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January 21, 2021 | https://www.sciencedaily.com/releases/2021/01/210121131726.htm | Diamonds need voltage | Diamond, like graphite, is a special form of carbon. Its cubic crystal structure and its strong chemical bonds give it its unique hardness. For thousands of years, it has also been sought after as both a tool and as a thing of beauty. Only in the 1950s did it become possible to produce diamonds artificially for the first time. | Most natural diamonds form in the Earth's mantle at depths of at least 150 kilometres, where temperatures in excess of 1500 degrees Celsius and enormously high pressures of several gigapascals prevail -- more than 10,000 times that of a well-inflated bicycle tyre. There are different theories for the exact mechanisms that are responsible for their formation. The starting material is carbonate-rich melts, i.e. compounds of magnesium, calcium or silicon which are rich in both oxygen and carbon.Because electro-chemical processes take place in the Earth's mantle and the melts and liquids that exist there can have a high electrical conductivity, researchers led by Yuri Palyanov of the V. S. Sobolev Institute of Geology and Mineralogy SB of the Russian Academy of Sciences Novosibirsk developed a model for the formation of diamonds in which highly localised electrical fields play a central role. According to this concept, applying less than even one volt -- a voltage lower than that provided by most household batteries -- provides electrons that trigger a chemical transformation process. These available electrons make it possible for certain carbon-oxygen compounds of the carbonates to become CO2 through a series of chemical reactions, ultimately leading to pure carbon in the form of diamond.To test their theory, the Russian research team developed a sophisticated experimental facility: A millimetre-sized platinum capsule was surrounded by a heating system which in turn was placed in a high-pressure apparatus needed to produce immense pressures of up to 7.5 gigapascals. Tiny, carefully constructed electrodes led into the capsule, which had been filled with carbonate or carbonate-silicate powders. Numerous experiments were run at temperatures between 1300 and 1600°C, some of which lasted for as long as 40 hours.The experiments conducted in Novosibirsk showed, as predicted, that tiny diamonds grow in the vicinity of the negative electrode over the course of several hours, but this happened only when a small voltage was applied; half a volt was already enough. With a diameter reaching a maximum of 200 micrometres, i.e. one fifth of a millimetre, the newly created crystals were smaller than a typical grain of sand. Furthermore, as expected, the other pure-carbon mineral graphite was found to form in experiments conducted at lower pressures. Further proof of the new mechanism came when the researcher reversed the voltage polarity -- diamonds then grew on the other electrode, exactly as expected. Without any voltage being suppled from outside the capsule neither graphite nor diamonds formed. In the vicinity of the diamonds, other minerals that are associated with the Earth's deep mantle were also found."The experimental facilities in Novosibirsk are absolutely impressive," says Michael Wiedenbeck, head of the SIMS laboratory at the GFZ, which is part of Potsdam's Modular Earth Science Infrastructure (MESI). He has been cooperating with the Russian researchers for more than ten years; he along with SIMS laboratory engineer Frédéric Couffignal, analysed diamonds produced by their Russian colleagues. In order to determine whether Yuri Palyanov's theory on diamond formation is completely correct, the isotopic composition of the diamonds had to be characterised very precisely.The Potsdam researchers used secondary ion mass spectrometry (SIMS) for this purpose. The Potsdam instrument is a highly specialized mass spectrometer, providing geoscientists from all over the world with high precision data from extremely small samples. "With this technology we can determine the composition of tiny areas on sub-millimetre samples with great precision," says Wiedenbeck. Thus, less than one billionth of a gram from a laboratory produced diamond needed to be removed using a very precisely targeted ion beam. Electrically charged atoms were then injected into a six metre long apparatus which separated each the billions of particles based on their individual mass. This technology makes it possible to separate chemical elements, and in particular it is possible to distinguish their lighter or heavier variants known as isotopes. "In this way we have shown that the ratio between the carbon isotopes 13C to 12C behaves exactly according the model developed by our colleagues in Novosibirsk. With this, we have contributed to the final piece of the puzzle, so to speak, to confirm this theory," says Wiedenbeck. However, it must be noted that this new method is not suitable for the mass production of large artificial diamonds."Our results clearly show that electric fields should be considered as an important additional factor that influences the crystallisation of diamonds. This observation may prove to be quite significant for understanding carbon isotope ratios shifts within the global carbon cycle," Yuri Polyanov sums up. | Climate | 2,021 |
January 21, 2021 | https://www.sciencedaily.com/releases/2021/01/210121131706.htm | Climate change puts hundreds of coastal airports at risk of flooding | Even a modest sea level rise, triggered by increasing global temperatures, would place 100 airports below mean sea level by 2100, a new study has found. | Scientists from Newcastle University modelled the risk of disruption to flight routes as a result of increasing flood risk from sea level rise.Publishing the findings in the journal They found that 269 airports are at risk of coastal flooding now. A temperature rise of 2C -- consistent with the Paris Agreement -- would lead to 100 airports being below mean sea level and 364 airports at risk of flooding. If global mean temperature rise exceeds this then as many as 572 airports will be at risk by 2100, leading to major disruptions without appropriate adaptation.The team developed a global ranking of airports at risk from sea level rise, which considers both the likelihood of flooding from extreme sea levels, level of flood protection, and the impacts in terms of flight disruption. Airports are at risk in Europe, North America and Oceania, with those in East and Southeast Asia and the Pacific dominating the top 20 list for airports at the highest risk.Suvarnabhumi Airport in Bangkok (BKK) and Shanghai Pudong (PVG) topped the list, while London City is the UK airport with the highest risk.Professor Dawson said: "These coastal airports are disproportionately important to the global airline network, and by 2100 between 10 and 20% of all routes will be at risk of disruption. Sea level rise therefore poses a serious risk to global passenger and freight movements, with considerable cost of damage and disruption.""Moreover, some airports, for example in low-lying islands, play critical roles in providing economic, social and medical lifelines"Adaptation options for coastal airports include increased flood protection, raising land and relocation.Professor Dawson added: "The cost of adaptation will be modest in the context of global infrastructure expenditure. However, in some locations the rate of sea level rise, limited economic resources or space for alternative locations will make some airports unviable." | Climate | 2,021 |
January 21, 2021 | https://www.sciencedaily.com/releases/2021/01/210121091332.htm | New eco-friendly way to make ammonia could be boon for agriculture, hydrogen economy | Chemical engineers at UNSW Sydney have found a way to make 'green' ammonia from air, water and renewable electricity that does not require the high temperatures, high pressure and huge infrastructure currently needed to produce this essential compound. | And the new production method -- demonstrated in a laboratory-based proof of concept -- also has the potential to play a role in the global transition towards a hydrogen economy, where ammonia is increasingly seen as a solution to the problem of storing and transporting hydrogen energy.In a paper published today in But since the beginning of the 1900s when it was first manufactured on a large scale, production of ammonia has been energy intensive -- requiring temperatures higher than 400oC and pressures greater than 200atm -- and all powered by fossil fuels.Dr Emma Lovell, a co-author on the paper from UNSW's School of Chemical Engineering, says the traditional way to make ammonia -- known as the Haber-Bosch process -- is only cost-effective when produced on a massive scale due to the huge amounts of energy and expensive materials required."The current way we make ammonia via the Haber-Bosch method produces more CO2 than any other chemical-making reaction," she says."In fact, making ammonia consumes about 2 per cent of the world's energy and makes 1 per cent of its CO2 -- which is a huge amount if you think of all the industrial processes that occur around the globe."Dr Lovell says in addition to the big carbon footprint left by the Haber-Bosch process, having to produce millions of tonnes of ammonia in centralised locations means even more energy is required to transport it around the world, not to mention the hazards that go with storing large amounts in the one place.She and her colleagues therefore looked at how to produce it cheaply, on a smaller scale and using renewable energy."The way that we did it does not rely on fossil fuel resources, nor emit CO2," Dr Lovell says."And once it becomes available commercially, the technology could be used to produce ammonia directly on site and on demand -- farmers could even do this on location using our technology to make fertiliser -- which means we negate the need for storage and transport. And we saw tragically in Beirut recently how potentially dangerous storing ammonium nitrate can be."So if we can make it locally to use locally, and make it as we need it, then there's a huge benefit to society as well as the health of the planet."ARC DECRA Fellow and co-author Dr Ali (Rouhollah) Jalili says trying to convert atmospheric nitrogen (N2) directly to ammonia using electricity "has posed a significant challenge to researchers for the last decade, due to the inherent stability of N2 that makes it difficult to dissolve and dissociate."Dr Jalili and his colleagues devised proof-of-concept lab experiments that used plasma (a form of lightning made in a tube) to convert air into an intermediary known among chemists as NOx -- either NO2- (nitrite) or NO3- (nitrate). The nitrogen in these compounds is much more reactive than N2 in the air."Working with our University of Sydney colleagues, we designed a range of scalable plasma reactors that could generate the NOx intermediary at a significant rate and high energy efficiency," he says."Once we generated that intermediary in water, designing a selective catalyst and scaling the system became significantly easier. The breakthrough of our technology was in the design of the high-performance plasma reactors coupled with electrochemistry."Professor Patrick Cullen, who led the University of Sydney team, adds: "Atmospheric plasma is increasingly finding application in green chemistry. By inducing the plasma discharges inside water bubbles, we have developed a means of overcoming the challenges of energy efficiency and process scaling, moving the technology closer to industrial adoption."Scientia Professor Rose Amal, who is co-director of ARC Training Centre for Global Hydrogen Economy, says in addition to the advantages of being able to scale down the technology, the team's 'green' method of ammonia production could solve the problem of storage and transport of hydrogen energy."Hydrogen is very light, so you need a lot of space to store it, otherwise you have to compress or liquify it," says Professor Amal."But liquid ammonia actually stores more hydrogen than liquid hydrogen itself. And so there has been increasing interest in the use of ammonia as a potential energy vector for a carbon-free economy."Professor Amal says ammonia could potentially be made in large quantities using the new green method ready for export."We can use electrons from solar farms to make ammonia and then export our sunshine as ammonia rather than hydrogen."And when it gets to countries like Japan and Germany, they can either split the ammonia and convert it back into hydrogen and nitrogen, or they can use it as a fuel."The team will next turn its attention to commercialising this breakthrough, and is seeking to form a spin-out company to take its technology from laboratory-scale into the field. | Climate | 2,021 |
January 21, 2021 | https://www.sciencedaily.com/releases/2021/01/210121131947.htm | Rocks show Mars once felt like Iceland | Once upon a time, seasons in Gale Crater probably felt something like those in Iceland. But nobody was there to bundle up more than 3 billion years ago. | The ancient Martian crater is the focus of a study by Rice University scientists comparing data from the Curiosity rover to places on Earth where similar geologic formations have experienced weathering in different climates.Iceland's basaltic terrain and cool weather, with temperatures typically less than 38 degrees Fahrenheit, turned out to be the closest analog to ancient Mars. The study determined that temperature had the biggest impact on how rocks formed from sediment deposited by ancient Martian streams were weathered by climate.The study by postdoctoral alumnus Michael Thorpe and Martian geologist Kirsten Siebach of Rice and geoscientist Joel Hurowitz of State University of New York at Stony Brook set out to answer questions about the forces that affected sands and mud in the ancient lakebed.Data collected by Curiosity during its travels since landing on Mars in 2012 provide details about the chemical and physical states of mudstones formed in an ancient lake, but the chemistry does not directly reveal the climate conditions when the sediment eroded upstream. For that, the researchers had to look for similar rocks and soils on Earth to find a correlation between the planets.The study published in The crater once contained a lake, but the climate that allowed water to fill it is the subject of a long debate. Some argue that early Mars was warm and wet, and that rivers and lakes were commonly present. Others think it was cold and dry and that glaciers and snow were more common."Sedimentary rocks in Gale Crater instead detail a climate that likely falls in between these two scenarios," said Thorpe, now a Mars sample return scientist at NASA Johnson Space Center contractor Jacobs Space Exploration Group. "The ancient climate was likely frigid but also appears to have supported liquid water in lakes for extended periods of time."The researchers were surprised that there was so little weathering of rocks on Mars after more than 3 billion years, such that the ancient Mars rocks were comparable to Icelandic sediments in a river and lake today."On Earth, the sedimentary rock record does a fantastic job of maturing over time with the help of chemical weathering," Thorpe noted. "However, on Mars we see very young minerals in the mudstones that are older than any sedimentary rocks on Earth, suggesting weathering was limited."The researchers directly studied sediments from Idaho and Iceland, and compiled studies of similar basaltic sediments from a range of climates around the world, from Antarctica to Hawaii, to bracket the climate conditions they thought were possible on Mars when water was flowing into Gale Crater."Earth provided an excellent laboratory for us in this study, where we could use a range of locations to see the effects of different climate variables on weathering, and average annual temperature had the strongest effect for the types of rocks in Gale Crater," said Siebach, a member of the Curiosity team who will be a Perseverance operator after the new lander touches down in February. "The range of climates on Earth allowed us to calibrate our thermometer for measuring the temperature on ancient Mars."The makeup of sand and mud in Iceland were the closest match to Mars based on analysis via the standard chemical index of alteration (CIA), a basic geological tool used to infer past climate from chemical and physical weathering of a sample."As water flows through rocks to erode and weather them, it dissolves the most soluble chemical components of the minerals that form the rocks," Siebach said. "On Mars, we saw that only a small fraction of the elements that dissolve the fastest had been lost from the mud relative to volcanic rocks, even though the mud has the smallest grain size and is usually the most weathered."This really limits the average annual temperature on Mars when the lake was present, because if it were warmer, then more of those elements would have been flushed away," she said.The results also indicated the climate shifted over time from Antarctic-like conditions to become more Icelandic while fluvial processes continued to deposit sediments in the crater. This shift shows the technique can be used to help track climate changes on ancient Mars.While the study focused on the lowest, most ancient part of the lake sediments Curiosity has explored, other studies have also indicated the Martian climate probably fluctuated and became drier with time. "This study establishes one way to interpret that trend more quantitatively, by comparison to climates and environments we know well on Earth today," Siebach said. "Similar techniques could be used by Perseverance to understand ancient climate around its landing site at Jezero Crater."In parallel, climate change, especially in Iceland, may shift the places on Earth best-suited for understanding the past on both planets, she said. | Climate | 2,021 |
January 21, 2021 | https://www.sciencedaily.com/releases/2021/01/210121131937.htm | Tree rings and the Laki volcano eruption: A closer look at climate | University of Arizona researchers read between the lines of tree rings to reconstruct exactly what happened in Alaska the year that the Laki Volcano erupted half a world away in Iceland. What they learned can help fine-tune future climate predictions. | In June 1783, Laki spewed more sulfur into the atmosphere than any other Northern Hemisphere eruption in the last 1,000 years. The Inuit in North America tell stories about the year that summer never arrived. Benjamin Franklin, who was in France at the time, noted the "fog" that descended over much of Europe in the aftermath, and correctly reasoned that it led to an unusually cold winter on the continent.Previous analyses of annual tree rings have shown that the entire 1783 growing season for the spruce trees in Alaska was colder than average. But Julie Edwards, a first-year doctoral student in the School of Geography, Development and Environment reasoned that since Laki erupted in June, it doesn't make sense to assume that the entire growing season, which starts in May for the trees they analyzed, was cooler than normal. So, she set out to solve the mystery.Edwards is lead author of a new paper published in the What happens to the climate a half a world away from the eruption reflects a combination of forces -- what the volcano did and the natural variability in the climate. To really understand how volcanoes affect the climate system, the UArizona team looked closely at the structure of tree rings to reveal what happened to the climate on a finer time scale.Edwards cut a very thin slice of tree ring and dyed it. Using computer software, she calculated the thickness of each of the stained cells. In warm years, the walls of these cells are thickened, and the wood appears darker. In cold years, however, the cell walls are thin, and the wood appears light and less dense."This is quantitative wood anatomy, and what we're doing is looking at cellular scale measurements on a cell-by-cell basis to see how climate is imprinting on cell growth throughout a season," Edwards said. "Using this technique, we can measure growth week by week."With this new way of seeing climate history, the researchers found that Alaskan trees in 1783 started off growing like they would in any normal year. A few months after Laki erupted, the trees suddenly stopped growing much earlier than in normal years, and only a very thin wall was formed in the last part of the ring."This suggests a sudden cooling at the end of the growing season, which is a different result than what you'd get by just looking at annual tree-ring width or wood density," said paper co-author Kevin Anchukaitis, an associate professor in the School of Geography, Development, and Environment and the Laboratory of Tree Ring Research. "What Julie's work shows is that using this fine-scale analysis, this week-to-week perspective from individual cells, it is possible to explain the previous and unexpected observation that the entire summer of 1783 was cold in Alaska and get a much better perspective on a truly extreme climate event."Edwards is one of only a few scientists in the United States to use the quantitative wood anatomy technique. The method has been previously used mostly in Europe, where she participated in a weeklong workshop in San Vito di Cadore, a small town in the Italian Alps, to learn the method from the people who perfected it.Edwards said it was also important for her and her collaborators to factor in natural variability in climate to check their result.Partnering with climate modeler Brian Zambri from the Massachusetts Institute of Technology, the team used a computer model to see how natural year-to-year variations in climate could have changed tree growth."The model was run a total of 80 times," Anchukaitis said. "The first 40 times, we allowed the eruption to occur. Then, the model was run another 40 times without the eruption, and we compared the results."The researchers saw a wide range of climate conditions following the eruptions. Some years were especially cold immediately following the eruption, but some were warm. Natural variability in the climate seems to overwhelm any cooling from the volcano."Many of the model runs agree with what the trees tell us," Anchukaitis said. "Summer starts normally and then a few months after the eruption, things rapidly get cold. This serves as independent evidence of what we interpret from the trees in 1783."The study demonstrates that the traditional way of studying tree rings doesn't always provide enough detail when studying rapid or extreme climate events, and also that natural variability in the system can be more important than once thought."We use these proxy measurements of past climate, including tree rings, as one way to validate our climate models," Edwards said. "We want to be able to look at these extreme scenarios and have our climate models accurately simulate them and understand the role of natural variability." | Climate | 2,021 |
January 21, 2021 | https://www.sciencedaily.com/releases/2021/01/210121131918.htm | World's largest lakes reveal climate change trends | NASA-funded research on the 11 largest freshwater lakes in the world coupled field and satellite observations to provide a new understanding of how large bodies of water fix carbon, as well as how a changing climate and lakes interact. | Scientists at the Michigan Tech Research Institute (MTRI) studied the five Laurentian Great Lakes bordering the U.S. and Canada; the three African Great Lakes, Tanganyika, Victoria and Malawi; Lake Baikal in Russia; and Great Bear and Great Slave lakes in Canada.These 11 lakes hold more than 50% of the surface freshwater that millions of people and countless other creatures rely on, underscoring the importance of understanding how they are being altered by climate change and other factors.The two Canadian lakes and Lake Tanganyika saw the greatest changes in primary productivity -- the growth of algae in a water body. Productivity fluctuations point to big changes in lake ecosystems."The base of the food chain in these lakes is algal productivity. These lakes are oceanic in size, and are teaming with phytoplankton -- small algae," said co-author Gary Fahnenstiel, a fellow at MTRI and recently retired senior research scientist for NOAA's Great Lakes Environmental Research Laboratory. "We measured the carbon fixation rate, which is the rate at which the algae photosynthesize in these lakes. As that rate changes, whether increasing or decreasing, it means the whole lake is changing, which has ramifications all the way up the food chain, from the zooplankton to the fish."Many factors affect these lakes. Climate change, increasing nutrients (eutrophication) and invasive species all combine to wreak systemwide change -- making it difficult to pinpoint specific causes, particularly from the ground with limited on-site observations.But satellite imagery has made sorting through the noise easier and provides insights over time and space. Michael Sayers, MTRI research scientist and study lead author, uses ocean color remote sensing -- making inferences about type and quantity of phytoplankton based on the color of the water -- to track freshwater phytoplankton dynamics."We've relied on NASA assets -- the MODIS satellite, which has been flying since 2002, to which we apply the algorithm and model we've been developing at MTRI for a decade," Sayers said. "When we start to tally the numbers of pixels as observations globally for 11 lakes for 16 years, it is really quite remarkable." The pixels observed per lake number "in the millions," he added.One of the most remarkable aspects of the results is just how fast changes in these freshwater lakes have occurred -- a noticeable amount in fewer than 20 years. The research contributes to NASA's Carbon Monitoring System's goal of determining how much freshwater lakes contribute to the global carbon cycle."Three of the largest lakes in the world are showing major changes related to climate change, with a 20-25% change in overall biological productivity in just the past 16 years," Fahnenstiel said.In the 16 years of data, Great Bear and Great Slave lakes in northern Canada saw the greatest increases in productivity, while Lake Tanganyika in southeastern Africa has seen decreases. The trends are linked to increases in water temperatures, as well as solar radiation and a reduction in wind speed.Sayers said looking at productivity, algal abundance, water clarity, water temperature, solar radiation and wind speeds at freshwater lakes provides a richer picture of the overall ecosystem."Temperature and solar radiation are factors of climate change," Sayers said. "Chlorophyll and water transparency changes are not necessarily caused by climate change, but could be caused by eutrophication or invasive species, like quagga mussels."The researchers used lake measurements performed by the Great Lakes Research Center research vessel fleet to ground truth the satellite observations and to provide input for model estimates.The article "Carbon Fixation Trends in Eleven of the World's Largest Lakes: 2003-2018" is published in the journal As the saying goes, water is life. Gaining a better understanding of how lake productivity changes affect the bodies of water so many people rely on is important to the communities who live on the lakeshores. It's also significant to the global community as we delve deeper into the role freshwater lakes play in the global carbon cycle and climate change.Phytoplankton are microscopic algae that photosynthesize, or make energy from sunlight. Carbon fixation is a part of photosynthesis -- inorganic carbon (particularly carbon dioxide) is converted into an organic compound by an organism. All living things on Earth contain organic carbon. The amount of phytoplankton and the rate at which they photosynthesize equal the carbon fixation rate in a lake. | Climate | 2,021 |
January 21, 2021 | https://www.sciencedaily.com/releases/2021/01/210121130827.htm | Climate-related species extinction possibly mitigated by newly discovered effect | Changes in climate that occur over short periods of time influence biodiversity. For a realistic assessment of these effects, it is necessary to also consider previous temperature trends going far back into Earth's history. Researchers from the University of Bayreuth and the University of Erlangen-Nuremberg show this in a paper for | The research team led by Bayreuth ecologist Prof. Dr. Manuel Steinbauer used palaeobiological and climate science models to investigate how a temperature trend over a long period of time and a subsequent short-term temperature change together affect species extinction. For this purpose, research data on eight different groups of marine and terrestrial animals were combined and analysed. In total, these groups include around 3,200 genera and more than 46,000 species. One of the key findings of the study was that the extent to which short-term temperature changes affect species diversity depends largely on the context of geographic and climatic history. If a long-lasting cooling is intensified by a subsequent short-term cooling, the climate-related extinction risk of the studied genera increases by up to 40 percent. However, this risk decreases if a long-term cooling of the Earth, such as occurred 40 million years ago up to the industrial age, is followed by a short-term warming.The researchers explain the effect they discovered by the fact that every species develops adaptations to certain climatic conditions in the course of its evolution. They retain these adaptations over a period of hundreds of thousands or millions of years. A long-term cooling therefore moves the species further and further away from the living conditions that are favourable for them and increases the risk of extinction. If a brief warming now follows, the habitat of the species will again approach the preferred climate. "Further studies are still needed to apply the results of our now published work to climate change as we are currently experiencing it. However, it seems very possible that human-induced global warming that began with the industrial age does not threaten global biodiversity as much as some predictions assume," explains Gregor Mathes M.Sc., first author of the study, who is currently writing a doctoral thesis in palaeobiology at the Universities of Bayreuth and Erlangen-Nuremberg."In the next two years, we wish to investigate even more closely the extent to which current forecasts of climate-induced species loss should be adjusted given that they ignore the context of geographic and climatic history. In the current biodiversity crisis, climate change is only one of many causes of species extinction. We humans are intervening in nature so extensively that a large number of species are endangered or have already disappeared from our planet forever as a result," Prof. Dr. Manuel Steinbauer from the Bayreuth Centre for Ecology and Environmental Research (BayCEER) adds. | Climate | 2,021 |
January 20, 2021 | https://www.sciencedaily.com/releases/2021/01/210120151017.htm | Late rainy season reliably predicts drought in regions prone to food insecurity | The onset date of the yearly rainy season reliably predicts if seasonal drought will occur in parts of Sub-Saharan Africa that are particularly vulnerable to food insecurity, and could help to mitigate its effects. Shraddhanand Shukla and colleagues at the University of California, Santa Barbara's Climate Hazards Center, present these findings in the open-access journal | Climate-driven seasonal drought can impact crop yields and is among major contributors to food insecurity, which can threaten people's lives and livelihoods. In the last five years, parts of Sub-Saharan Africa have experienced a significant rise in food insecurity, sometimes requiring emergency food assistance. Early warning systems that reliably predict conditions likely to lead to food insecurity could help drive timely actions to mitigate these effects.Shukla and colleagues hypothesized that the onset date of the rainy season, as calculated from precipitation data, could serve as such a warning. To explore this possibility, they analyzed the relationship between the onset date, drought conditions observed via satellite images of vegetation cover, and the risks of food insecurity based on quarterly reports on food insecurity in across Sub-Saharan Africa from April 2011 through February 2020.The analysis showed that a delay of about 10 days from the median date of onset of the rainy season was associated with a significantly higher likelihood of seasonal drought in regions with the highest risk of acutesevere food insecurity. A 20-day delay indicated a 50 percent chance of drought in those regions. Further analysis confirmed the predictive relationship between rainy season onset date and drought risk across Sub-Saharan Africa as a whole, and particularly in East Africa.These findings suggest that the onset date of the rainy season could be an important component of an early warning system for droughts likely to lead to food insecurity in Sub-Saharan Africa. Further research could examine the relationship between onset date and other food insecurity indicators, such as high-resolution data on crop yields and prices or mid-season livestock prices.The authors add: "Timing of rainfall onset can be tracked using remotely sensed observations and forecasted using climate models, and the results of this study show that it can be a reliable indicator of agricultural droughts, particularly in the most food insecure regions of Sub-Saharan Africa, which makes it a simple yet powerful tool to support effective early warning of food insecurity, thus saving lives and livelihood." | Climate | 2,021 |
January 21, 2021 | https://www.sciencedaily.com/releases/2021/01/210121092828.htm | Methane emissions from abandoned oil and gas wells underestimated | A recent McGill study published in Environmental Science and Technology finds that annual methane emissions from abandoned oil and gas (AOG) wells in Canada and the US have been greatly underestimated -- by as much as 150% in Canada, and by 20% in the US. Indeed, the research suggests that methane gas emissions from AOG wells are currently the 10th and 11th largest sources of anthropogenic methane emission in the US and Canada, respectively. Since methane gas is a more important contributor to global warming than carbon dioxide, especially over the short term, the researchers believe that it is essential to gain a clearer understanding of methane emissions from AOG wells to understand their broader environmental impacts and move towards mitigating the problem. | The researchers show that the difficulties in estimating overall methane emissions from AOG wells in both countries are due to a lack of information about both the quantities of methane gas being emitted annually from AOG wells (depending on whether and how well they have been capped), and about the number of AOG wells themselves."Oil and gas development started in the late 1850s both in Canada and the US," explains Mary Kang, the senior author on the paper and an assistant professor in the Department of Civil Engineering at McGill. "Many companies that dug wells have come and gone since then, so it can be hard to find records of the wells that once existed."To determine the number of AOG wells, the researchers analyzed information from 47 state, provincial or territorial databases as well as from research articles and national repositories of drilled and active wells in the US and Canada.They found that, of the over 4,000,000 AOG wells they estimate to exist in the US, more than 500,000 are undocumented by the relevant state agencies. A similar picture emerges in Canada. The Canadian Association of Petroleum Producers (CAPP) only has records going back to 1955 although historical documents confirm that oil and gas activity in Canada began in the 1850s. Based on the various sources they examined, the researchers estimate that there are over 370,000 AOG wells in Canada. Over 60,000 of are not included in databases of provincial or territorial agencies.To gain a better sense of exactly how much methane was being emitted from the wells, the researchers analyzed close to 600 direct measurements of methane emissions drawn from existing studies covering the AOG wells in the states of Ohio, Wyoming, Utah, Colorado, Oklahoma, West Virginia and Pennsylvania in the US and from British Columbia and New Brunswick in Canada. They developed different scenarios to attribute different levels of annual methane emissions to the wells, depending on what is known of the plugging status of the wells as well as whether they were oil or gas wells."We see that methane emissions from abandoned wells can vary regionally, highlighting the importance of gathering measurements from Texas and Alberta which have the highest percentage of wells in the U.S. and Canada and no prior measurements," adds James P. Williams, the first author on the study and a Ph.D. student in the Department of Civil Engineering at McGill.All five scenarios show annual emissions of methane gas from AOG wells in the US that are approximately 1/5th higher than the amount that the US EPA's estimates for 2018. In Canada, the study findings suggest that methane emissions from AOG wells in 2018 were nearly three times higher than estimated by Environment and Climate Change Canada."As society transitions away from fossil fuels, the millions of oil and gas wells around the world will be abandoned," says Kang. "It is critical to determine the climate, air, water and other environmental impacts of these wells quickly."The research was funded by Fonds de Recherche du Quebec Nature et Technologie, the McGill Engineering Doctoral Award and the McGill Graduate Mobility Award. | Climate | 2,021 |
January 21, 2021 | https://www.sciencedaily.com/releases/2021/01/210121091335.htm | As oceans warm, large fish struggle | Warming ocean waters could reduce the ability of fish, especially large ones, to extract the oxygen they need from their environment. Animals require oxygen to generate energy for movement, growth and reproduction. In a recent paper in the | The model is based on physicochemical principles that look at oxygen consumption and diffusion at the gill surface in relation to water temperature and body size. Predictions were compared against actual measurements from over 200 fish species where oxygen consumption rates were measured at different water temperatures and across individuals of different body sizes."Our data suggest that, as temperature increases, the demand for oxygen of many fish species will exceed their capacity to extract oxygen from the environment through their gills," explains Juan Rubalcaba, a Marie-Curie Postdoctoral Fellow at McGill, and lead author on the paper. "As a result, the aerobic capacity of fish decreases in warming waters, and this reduction may be more important in larger fishes. This tells us that global warming could limit the aerobic capacity of fish, impairing their physiological performance in the future.""Water temperature is already rising worldwide as a consequence of climate change and many fish species need to cope with this rapid temperature change, either by migrating toward colder regions or by adopting different life strategies such as shrinking in size over generations in order to avoid respiratory constraints," said Art Woods, a professor of biological sciences at the University of Montana, and the senior author on the paper. "By including oxygen, this model stands apart by predicting observed patterns of variation in metabolic rate among fishes worldwide than current theories, which focus primarily on body size and temperature."The research was funded by the European Commission's Marie Sk?odowska-Curie Individual Fellowship | Climate | 2,021 |
January 19, 2021 | https://www.sciencedaily.com/releases/2021/01/210119122100.htm | New carbon budget framework provides a clearer view of our climate deadlines | Just how close are the world's countries to achieving the Paris Agreement target of keeping climate change limited to a 1.5°C increase above pre-industrial levels? | It's a tricky question with a complex answer. One approach is to use the remaining carbon budget to gauge how many more tonnes of carbon dioxide we can still emit and have a chance of staying under the target laid out by the 2015 international accord. However, estimates of the remaining carbon budget have varied considerably in previous studies because of inconsistent approaches and assumptions used by researchers.The researchers estimate that between 230 and 440 billion more tonnes of CO"The wide range of carbon budget estimates in the literature has contributed to both confusion and inaction in climate policy circles," explains Matthews, the Concordia Research Chair in Climate Science and Sustainability. "This is the first time we have gone through all the uncertainties and included them in a single estimate."Matthews identifies five key uncertain parameters affecting the remaining carbon budget.The first is the amount of observed warming that has occurred to date; the second is the amount of COUsing a new set of equations, the researchers were able to relate these parameters to each other and calculate a unified distribution of the remaining carbon budget.The 440 billion tonnes of COThese numbers are based on accounting for geophysical uncertainties (those related to scientific understanding of the climate system), but not socioeconomic ones (those relating to human decisions and socioeconomic systems). The decisions humans make in the near-term matter greatly and have the potential to either increase or decrease the size of the remaining carbon budget. In the new framework, these decisions could add (or remove) as much as 170 billion tonnes of COThe COVID-19 pandemic has presented humans with an opportunity, Matthews argues. The year 2020 experienced a noticeable drop in emissions from 2019 due in large part to reduced human mobility. If we are able to direct recovery investments in ways that would continue this decrease (rather than allowing emissions to rebound) we would greatly increase our chances of remaining under the 1.5°C Paris Agreement target.Another source of cautious optimism lies with the incoming Biden administration in the United States, which has made climate change a priority."I am optimistic that having national leadership in the US that can mobilize efforts on climate change will make a big difference over the coming years," Matthews adds. "The momentum is shifting in the right direction, but it is still not happening fast enough." | Climate | 2,021 |
January 19, 2021 | https://www.sciencedaily.com/releases/2021/01/210119122046.htm | Acidification impedes shell development of plankton off the U.S. West Coast, study shows | Shelled pteropods, microscopic free-swimming sea snails, are widely regarded as indicators for ocean acidification because research has shown that their fragile shells are vulnerable to increasing ocean acidity. | A new study, published in the journal Sometimes called sea butterflies because of how they appear to flap their "wings" as they swim through the water column, fat-rich pteropods are an important food source for organisms ranging from other plankton to juvenile salmon to whales. They make shells by fixing calcium carbonate in ocean water to form an exoskeleton."It appears that pteropods make thinner shells where upwelling brings water that is colder and lower in pH to the surface, " said lead author Lisette Mekkes of Naturalis Biodiversity Centers and the University of Amsterdam in the Netherlands. Mekkes added that while some shells also showed signs of dissolution, the change in shell thickness was particularly pronounced, demonstrating that acidified water interfered with pteropods' ability to build their shells.The scientists examined shells of pteropods collected during the 2016 NOAA Ocean Acidification Program research cruise in the northern California Current Ecosystem onboard the NOAA Ship Ronald H. Brown. Shell thicknesses of 80 of the tiny creatures -- no larger than the head of a pin -- were analyzed using 3D scans provided by micron-scale computer tomography, a high-resolution X-ray technique. The scientists also examined the shells with a scanning electron microscope to assess if thinner shells were a result of dissolution. They also used DNA analysis to make sure the examined specimens belonged to a single population."Pteropod shells protect against predation and infection, but making thinner shells could also be an adaptive or acclimation strategy," said Katja Peijnenburg, group leader at Naturalis Biodiversity Center. "However, an important question is how long can pteropods continue making thinner shells in rapidly acidifying waters?"The California Current Ecosystem along the West Coast is especially vulnerable to ocean acidification because it not only absorbs carbon dioxide from the atmosphere, but is also bathed by seasonal upwelling of carbon-dioxide rich waters from the deep ocean. In recent years these waters have grown increasingly corrosive as a result of the increasing amounts of atmospheric carbon dioxide absorbed into the ocean."Our research shows that within two to three months, pteropods transported by currents from the open-ocean to more corrosive nearshore waters have difficulty building their shells," said Nina Bednarsek, a research scientist from the Southern California Coastal Water Research Project in Costa Mesa, California, a coauthor of the study.Over the last two-and-a-half centuries, scientists say, the global ocean has absorbed approximately 620 billion tons of carbon dioxide from emissions released into the atmosphere by burning fossil fuels, changes in land-use, and cement production, resulting in a process called ocean acidification."The new research provides the foundation for understanding how pteropods and other microscopic organisms are actively affected by progressing ocean acidification and how these changes can impact the global carbon cycle and ecological communities," said Richard Feely, NOAA Pacific Marine Environmental Laboratory and chief scientist for the cruise.This research was supported by NOAA's Ocean Acidification Program. | Climate | 2,021 |
January 18, 2021 | https://www.sciencedaily.com/releases/2021/01/210118113129.htm | Climate change will alter the position of the Earth's tropical rain belt | Future climate change will cause a regionally uneven shifting of the tropical rain belt -- a narrow band of heavy precipitation near the equator -- according to researchers at the University of California, Irvine and other institutions. This development may threaten food security for billions of people. | In a study published today in According to the study, a northward shift of the tropical rain belt over the eastern Africa and the Indian Ocean will result in future increases of drought stress in southeastern Africa and Madagascar, in addition to intensified flooding in southern India. A southward creeping of the rain belt over the eastern Pacific Ocean and Atlantic Ocean will cause greater drought stress in Central America."Our work shows that climate change will cause the position of Earth's tropical rain belt to move in opposite directions in two longitudinal sectors that cover almost two thirds of the globe, a process that will have cascading effects on water availability and food production around the world," said lead author Antonios Mamalakis, who recently received a Ph.D. in civil & environmental engineering in the Henry Samueli School of Engineering at UCI and is currently a postdoctoral fellow in the Department of Atmospheric Science at Colorado State University.The team made the assessment by examining computer simulations from 27 state-of-the-art climate models and measuring the tropical rain belt's response to a future scenario in which greenhouse gas emissions continue to rise through the end of the current century.Mamalakis said the sweeping shift detected in his work was disguised in previous modelling studies that provided a global average of the influence of climate change on the tropical rain belt. Only by isolating the response in the Eastern and Western Hemisphere zones was his team able to highlight the drastic alterations to come over future decades.Co-author James Randerson, UCI's Ralph J. & Carol M. Cicerone Chair in Earth System Science, explained that climate change causes the atmosphere to heat up by different amounts over Asia and the North Atlantic Ocean."In Asia, projected reductions in aerosol emissions, glacier melting in the Himalayas and loss of snow cover in northern areas brought on by climate change will cause the atmosphere to heat up faster than in other regions," he said. "We know that the rain belt shifts toward this heating, and that its northward movement in the Eastern Hemisphere is consistent with these expected impacts of climate change."He added that the weakening of the Gulf Stream current and deep-water formation in the North Atlantic is likely to have the opposite effect, causing a southward shift in the tropical rain belt across the Western Hemisphere."The complexity of the Earth system is daunting, with dependencies and feedback loops across many processes and scales," said corresponding author Efi Foufoula-Georgiou, UCI Distinguished Professor of Civil & Environmental Engineering and the Henry Samueli Endowed Chair in Engineering. "This study combines the engineering approach of system's thinking with data analytics and climate science to reveal subtle and previously unrecognized manifestations of global warming on regional precipitation dynamics and extremes."Foufoula-Georgiou said that a next step is to translate those changes to impacts on the ground, in terms of flooding, droughts, infrastructure and ecosystem change to guide adaptation, policy and management. | Climate | 2,021 |
January 18, 2021 | https://www.sciencedaily.com/releases/2021/01/210118113112.htm | Low-carbon policies can be 'balanced' to benefit small firms and average households | Some of the low-carbon policy options currently used by governments may be detrimental to the households and small businesses less able to manage added short-term costs from energy price hikes, according to a new study. | However, it also suggests that this menu of decarbonising policies, from quotas to feed-in tariffs, can be designed and balanced to benefit local firms and lower-income families -- vital for achieving 'Net Zero' carbon and a green recovery.University of Cambridge researchers combed through thousands of studies to create the most comprehensive analysis to date of widely used types of low-carbon policy, and compared how they perform in areas such as cost and competitiveness.The findings are published today in the journal "Preventing climate change cannot be the only goal of decarbonisation policies," said study lead author Dr Cristina Peñasco, a public policy expert from the University of Cambridge."Unless low-carbon policies are fair, affordable and economically competitive, they will struggle to secure public support -- and further delays in decarbonisation could be disastrous for the planet."Around 7,000 published studies were whittled down to over 700 individual findings. These results were coded to allow comparison -- with over half the studies analysed "blind" by different researchers to avoid bias.The ten policy "instruments" covered in the study include forms of investment -- targeted R&D funding, for example -- as well as financial incentives including different kinds of subsidies, taxes, and the auctioning of energy contracts.The policies also include market interventions -- e.g. emissions permits; tradable certificates for clean or saved energy -- and efficiency standards, such as those for buildings.Researchers looked at whether each policy type had a positive or negative effect in various environmental, industrial and socio-economic areas.When it came to "distributional consequences" -- the fairness with which the costs and benefits are spread -- the mass of evidence suggests that the impact of five of the ten policy types are far more negative than positive."Small firms and average households have less capacity to absorb increases in energy costs," said co-author Laura Diaz Anadon, Professor of Climate Change Policy."Some of the investment and regulatory policies made it harder for small and medium-size firms to participate in new opportunities or adjust to changes."If policies are not well designed and vulnerable households and businesses experience them negatively, it could increase public resistance to change -- a major obstacle in reaching net zero carbon," said Anadon.For example, feed-in tariffs pay renewable electricity producers above market rates. But these costs may bump energy prices for all if they get passed on to households -- leaving the less well-off spending a larger portion of their income on energy.Renewable electricity traded as 'green certificates' can redistribute wealth from consumers to energy companies -- with 83% of the available evidence suggesting they have a "negative impact," along with 63% of the evidence for energy taxes, which can disproportionately affect rural areas.However, the vast tranche of data assembled by the researchers reveals how many of these policies can be designed and aligned to complement each other, boost innovation, and pave the way for a fairer transition to zero carbon.For example, tailoring feed-in tariffs (FiTs) to be "predictable yet adjustable" can benefit smaller and more dispersed clean energy projects -- improving market competitiveness and helping to mitigate local NIMBYism*.Moreover, revenues from environmental taxes could go towards social benefits or tax credits e.g. reducing corporate tax for small firms and lowering income taxes, providing what researchers call a "double dividend": stimulating economies while reducing emissions.The researchers argue that creating a "balance" of well-designed and complementary policies can benefit different renewable energy producers and "clean" technologies at various stages.Government funding for research and development (R&D) that targets small firms can help attract other funding streams -- boosting both eco-innovation and competitiveness. When combined with R&D tax credits, it predominantly supports innovation in startups rather than corporations.Government procurement, using tiered contracts and bidding, can also improve innovation and market access for smaller businesses in "economically stressed" areas. This could aid the "levelling up" between richer and poorer regions as part of any green recovery."There is no one-size-fits-all solution," said Peñasco. "Policymakers should deploy incentives for innovation, such as targeted R&D funding, while also adapting tariffs and quotas to benefit those across income distributions."We need to spur the development of green technology at the same time as achieving public buy-in for the energy transition that must start now to prevent catastrophic global heating," she said. | Climate | 2,021 |
January 15, 2021 | https://www.sciencedaily.com/releases/2021/01/210115163350.htm | Scientists offer road map to improve environmental observations in the Indian Ocean | A group of more than 60 scientists have provided recommendations to improve the Indian Ocean Observing System (IndOOS), a basin-wide monitoring system to better understand the impacts of human-caused climate change in a region that has been warming faster than any other ocean. | The group, led by Lisa Beal, professor of ocean sciences at the University of Miami (UM) Rosenstiel School of Marine and Atmospheric Science, provides a road map for an enhanced IndOOS to better meet the scientific and societal needs for more reliable environmental forecasts in the next decade. The 136 actionable recommendations from the three-year, internationally coordinated review were published in the The scientists call for four major improvements to the current observing system:1) more chemical and biological measurements in at-risk ecosystems and fisheries;2) expansion into the western tropics to improve understanding of the monsoon;3) better-resolved upper ocean processes to improve predictions of rainfall, drought, and heat waves; and4) expansion into key coastal regions and the deep ocean to better constrain the basin-wide energy budget.Although the smallest of the major oceans on Earth, the Indian Ocean is home to roughly one-third of the global population living among the 22 countries that border its rim. Many of these countries are developing or emerging economies vulnerable to climate changes such as sea level rise and more extreme weather events. The Indian Ocean also influences climate globally and is thought to have played a key role in regulating global mean surface temperatures.The Indian Ocean Observing System, established in 2006, is a multinational network of sustained oceanic measurements that underpin understanding and forecasting of weather and climate for the Indian Ocean region and beyond. IndOOS is part of the Global Ocean Observing System (GOOS) which is coordinated through the World Meteorological Organization and the Intergovernmental Oceanographic Commission of the United Nations.IndOOS-2 will require new agreements and partnerships with and among Indian Ocean rim countries, creating opportunities for them to enhance their monitoring and forecasting capacity, said the authors. | Climate | 2,021 |
January 15, 2021 | https://www.sciencedaily.com/releases/2021/01/210115110333.htm | Stuck in a rut: Ocean acidification locks algal communities in a simplified state | Out with the old, in with the new, as the New Year's saying goes, but not where the marine environment is concerned. Researchers from Japan have discovered that ocean acidification keeps algal communities locked in a simplified state of low biodiversity. | In a study published on 11th January 2021 in Ocean acidification is the continuing increase in the acidity of the Earth's oceans, caused by the absorption of atmospheric carbon dioxide (CO"Ocean acidification is harmful to a lot of different marine organisms," says lead author of the study Professor Ben P. Harvey. "This affects not only ecosystem functions, but the goods and services that people get from marine resources."To examine the changes caused by CO"We found that the tiles ended up being taken over by turf algae in the acidified conditions, and the communities had lower diversity, complexity and biomass," explains Professor Harvey. "This pattern was consistent throughout the seasons, keeping these communities locked in simplified systems that had low biodiversity."The team also transplanted established communities between the two conditions. The transplanted communities ultimately matched the other communities around them (i.e., high biodiversity, complexity and biomass in the reference conditions, and vice versa for the acidified conditions)."By understanding the ecological processes that change community structure, we can better evaluate how ocean acidification is likely to alter communities in the future," says Professor Harvey.The results of this study highlight that if atmospheric CO | Climate | 2,021 |
January 15, 2021 | https://www.sciencedaily.com/releases/2021/01/210115110303.htm | Intertropical Convergence Zone limits climate predictions in the tropical Atlantic | El Niño or correctly El Niño -- Southern Oscillation (ENSO) is the strongest natural climate fluctuation on time scales of a few years. Through ocean and atmosphere interactions, El Niño (Spanish for The Christ Child) events cause significant warming of the eastern Pacific, accompanied by catastrophic rainfall over South America and droughts in the Indo-Pacific region. Powerful events have global effects that reach even into the extra-tropics. There is also an El Niño variant in the Atlantic, called the Atlantic Niño, which, for example, has effects on rainfall in West Africa as well as the development of tropical cyclones over the eastern tropical Atlantic. A better understanding of the poorly investigated little brother of the Pacific El Niño in the Atlantic could potentially improve climate forecasts in the region. The study now provides first results and suggests useful predictability of the Atlantic Niño. | "The Atlantic Niño, like its Pacific counterpart, exhibits a characteristic asymmetric structure in the changes of sea surface temperatures and surface winds from east to west, with the strongest warming occurring in the east. However, there are some differences: the Atlantic events are of smaller magnitude, shorter duration and less predictable, but the reasons for these differences are not fully understood," explains Mojib Latif from GEOMAR, co-author of the study. The researchers used data from various sources, including in situ observations, satellite and reanalysis products.Unlike the Pacific El Niño, which typically lasts for a year, the Atlantic Niño is limited to just a few months. The team of scientists have now been able to decipher the cause. "In our analyses, we identified the movement of the Intertropical Convergence Zone (ITCZ), a band of heavy rainfall stretching across the tropical Atlantic, as the reason," Latif continues. "The seasonal migration of the ITCZ has a significant influence on the interaction of sea surface temperature with the overlying atmosphere. Only when the ITCZ is very close to or over the equator the interaction is strong enough to cause large climate changes," explains Hyacinth Nnamchi, lead author of the study. "Or put another way: The fluctuations in sea surface temperature during the Atlantic Niño are not strong enough to keep the ITCZ at the equator, as in the case of its Pacific big brother," Nnamchi continues.The authors intend to use their new findings to represent the ITCZ more realistically in climate models in order to enhance prediction of tropical precipitation. "The ultimate goal is seasonal climate forecasts that enable, for example, planning for agriculture and water management in West Africa," says Latif. Unlike in mid-latitudes, this is certainly possible for the tropics, says the climate researcher. | Climate | 2,021 |
January 14, 2021 | https://www.sciencedaily.com/releases/2021/01/210114180617.htm | Climate change doesn't spare the insects | In a normal year, biologists Daniel Janzen and Winnie Hallwachs spend about six months in Costa Rica, where they conduct research and pursue conservation efforts in Área de Conservación Guanacaste (ACG), a World Heritage Site in the northwest that encompasses, a network of parks and preserves they helped establish in the 1980s and that has grown to more than 400,000 acres, including marine, dry forest, cloud forest, and rain forest environments. | In 2020 that is where the married couple was when the COVID-19 pandemic took hold of the world, and compelled them to extend their stay in the virus-free forest until the fall, when they felt safe enough to travel back to their other home in Philadelphia."With modern laptops and internet, we could watch the world go by from the safety of the forest," says Janzen, a biology professor in the School of Arts & Sciences.The extra time in the forest gave them added time for reflection, some of the fruits of which appear in a piece published this week in the Proceedings of the National Academy of Sciences, part of a special issue on global insect decline.Their contribution draws on data collected since the 1970s on insect abundance and diversity in the tropics, as well as on observations about climate change that go back even further. Although the ACG's protected status has effectively eliminated certain threats to biodiversity loss, such as fire, hunting, deforestation, and pesticide use, the creatures that dwell there are not exempt from what Janzen and Hallwachs call the "heterogenous blanket" of climate change effects."What we have seen and lived since the mid-1970s, unambiguously, in our Costa Rican tropical wild world is that the biomass and species richness of insect individuals and species, and their interactions with everything, are decomposing," they write.To respond to this decline, the scientists have focused their efforts locally. Keeping track of the effects of climate change through consistent monitoring is essential, they say, but what even more critical is engaging the people who own the preserved land: all five million Costa Ricans, in this case. Janzen and Hallwachs are internationally known for their work on this front, having created a model in ACG that empowers and employs local people in conservation work and attempts to facilitate the movement of these processes throughout the national park system and abroad.In their article, the researchers describe a new approach to expand on these successes: BioAlfa, a nationwide program designed to enlist Costa Ricans themselves in hands-on learning and research about their nation's wild ecosystems. The initiative's name comes from the Spanish for bioliterate, "bioalfabetizado.""The tradition in tropical countries is that when you want to know something about the biology of your country, expeditions from the North come and do studies of one sort or another and then they take the information home with them," Janzen and Hallwachs say. "What we said is, 'Look, you're capable of doing this all yourselves. You can find all the bugs and the plants and the birds and everything in your own country and, in the process, learn about them.'"Janzen and Hallwachs never intended to explicitly study climate change. But its effects have been impossible to ignore. They note that in the 1980s cloud cover was a constant presence over the aptly named cloud forests of ACG, shrouding peaks like Volcán Orosí and Volcán Cacao. Yet the cloud layer shrank by the 1990s and now,many days pass with no cloud cover whatsoever. The result is a drying of forest ecosystems to the detriment of insects and other wildlife that thrive in damp leaf litter and moist conditions, to say nothing of the drying waterways that used to adequately irrigate flatland crops and other development.The ACG now experiences far more days of temperatures that approach and exceed 90 degrees Fahrenheit than it did in past decades. In addition, a prolonged dry season and greater irregularities in rainfall amount and timing compound the stresses on the biodiversity that lives there. Essentially all tropical organisms use weather cues to guide their lives, and when these change and fracture everyone takes a hit.Janzen and Hallwachs note that these climatic perturbations have extracted a price on insect biodiversity, a bellwether for impacts on the food web bottom to top. In their report, they compare photos from moth surveys -- conducted at night by using a bright light to attract moths to a light-colored sheet, where they can be counted -- that indicate a dramatic drop in both moth numbers and species diversity since the 1980s.Looking at a different types of insects, they say that, despite a constant search effort by ACG's on-the-ground staff of trained and experienced neighbor researchers, the overall number of caterpillars found during regular surveys has fallen in half since 2005, a clear sign of decline.Supporting this finding, when caterpillars are found, they are now less likely to be parasitized by another insect species. About a fifth of caterpillars were found parasitized in 1985; that has fallen to just 5% in recent years. While this may be a good thing for individual caterpillars, it's a worrying sign overall. Because parasites are hyperspecialized to associate with particular caterpillar species, Janzen says that this lack of parasitized caterpillars suggests that caterpillar numbers are so few that the parasites are unable to locate their desired species and maintain their populations."When caterpillar density goes down, the parasites go extinct faster," Janzen says. "So now you've lost that carnivore. And you repeat that a thousand times, 10,000 times."Mitigating climate change can be an overwhelming task, and Janzen says that "little guys" -- like the economically-small but biodiversity-big country of Costa Rica -- are unlikely to make a big-picture impact, except by example. In his eyes, it's essential for small tropical nations to focus energy on creating the conditions that enable the survivors of climate change to maintain a foothold. And that is where BioAlfa comes in.While international conservation groups contribute money to preserve land in lush, biodiverse locales, such as ACG, the researchers argue that gaining buy-in from all levels of the owners of that preserved land, rather than outsiders who may never step foot in the country, is a necessary ingredient in tropical conservation."Charismatic vertebrates, tourist snapshots, and marketable big tree trunks are not even 0.001% of tropical biodiversity," Janzen and Hallwachs write. "The millions to billions of species, and billions of wild interactions still viable, are largely invisible without bioliteracy."That's why underscoring bioliteracy is the foundation of BioAlfa. The Penn scientists' vision is that, just as elementary school children are taught to read, they should also be taught about the biodiversity around them, and not just in a classroom but by going on the land and learning by doing. And like reading, this knowledge becomes something one takes into whatever social sector becomes home.This enhanced bioliteracy would then feed back into conservation, they say. Not only might a greater understanding of ecosystems among Costa Ricans translate into greater appreciation but concrete results by using biodiversity information wherever they are. Specifically, Janzen and Hallwachs want to expand the practice of having local researchers carry out their DNA barcoding work, in which species are identified by sequencing stretches of their genetic material.While the Costa Rican government has committed to the idea of BioAlfa, fully fleshing it out over 10 years will take an estimated $100 million, a hefty sum that Janzen and Hallwachs hope can come from both international governmental and private sources."Right now Costa Rica has the political permission for this project, but it also needs the financial permission," says Janzen.For their part, the couple continues to plug away at building their biodiversity inventory and studies in ACG, while sharing their successes at international meetings (for now virtually), hoping that other tropical nations will follow in their footsteps, protecting land to, in the words of their scientific paper, "be kind to the survivors" of climate change.As soon as they're vaccinated for the coronavirus, Janzen and Hallwachs plan to be back on the ground in Costa Rica, continuing to pursue that goal.Daniel Janzen is professor of biology and Thomas G. and Louise E. DiMaura Term Chair in the School of Arts & Sciences' Department of Biology at the University of Pennsylvania.Winnie Hallwachs is research biologist in the School of Arts & Sciences' Department of Biology at the University of Pennsylvania. | Climate | 2,021 |
January 14, 2021 | https://www.sciencedaily.com/releases/2021/01/210114163900.htm | Measuring the belowground world | If you asked people which group of animals is the most abundant on earth, hardly anyone would know the right answer. Ants? Fish? No, and not humans either. The answer is nematodes, also known as roundworms. Four out of five animals on earth belong to this group, and the reason hardly anyone is aware of the fact is that they live underground, invisible to us. Together with thousands of other soil organisms, they quietly, discreetly and constantly perform enormously important services for the world above them. | The soil is one of the most species-rich habitats in existence. Living under one square meter of healthy soil you can find up to 1.5 kilograms of organisms: among others, roundworms, earthworms, springtails, mites and insect larvae. There is also a multitude of microorganisms including bacteria, protists and fungi. They eat and transform living and dead animal and plant material into nutrients which become the basis for growth and new life. Without soil organisms, no plants would be able to grow and no humans could live.It is therefore all the more astonishing that soils have so far hardly featured in international strategies for protecting biodiversity. The authors of the new article in Healthy soils are becoming increasingly rare. They suffer the burden of intensive cultivation with heavy machinery, fertilisers and pesticides, are compacted, built over or are lost due to wind and water erosion. Global warming is putting them under additional pressure. According to the German Heinrich Böll Foundation, around 24 billion tons of fertile soil are lost worldwide every year. As a result, the soils' wide variety of services such as water purification and protection against plant diseases gradually decline. In addition, soils are the most important carbon reservoir on earth and therefore help slow global climate warming.According to the researchers, these services are given far too little attention in the political debate. "Up to now, soil conservation has been mostly reduced to the impacts related to soil erosion and its importance for agriculture," said first author Dr Carlos Guerra (iDiv, MLU). "It's about time that soil conservation policies consider the protection of soil organisms and ecosystem functions more than just for food production and other productive systems. Soil biodiversity monitoring and conservation can support the achievement and tracking of many sustainability goals, targeting areas such as climate, food and biodiversity protection.""Protection measures have so far mainly focused on life above ground, for example in the designation of protected areas," said senior author Dr Diana Wall from Colorado State University. However, since these do not necessarily benefit underground biodiversity, the specific needs of the biotic communities in the soil have to be taken into account.In order to be able to decide which regions of the world are particularly in need of protection, and which protective measures are appropriate, sufficient information must be available on the status and trends of biodiversity in soils. Since this has not been the case so far, the researchers launched the Soil BON monitoring network. "We want to move biodiversity in soils into the focus of conservation efforts. To do this, we must provide policymakers with the necessary information to support decision-making," said senior author Prof Nico Eisenhauer, research group leader at iDiv and Leipzig University. "Soil BON will produce and support the production of the relevant data to achieve this goal."The purpose of Soil BON is to help gather equivalent soil data, comprehensively and over extended periods of time. What is required is an internationally recognised standard which sets out what is to be recorded and how. The researchers propose a holistic system for this: the so-called Essential Biodiversity Variables (EBVs). EBVs are key parameters for measuring biodiversity. The concept was developed by, among others, iDiv and includes criteria such as soil respiration, nutrient turnover and genetic diversity. Indicators are derived from the EBVs which then serve as a basis for soil status evaluation and subsequent decisions regarding the level and type of protection necessary for the soils.According to the researchers, their proposed monitoring and indicator system will enable the worldwide condition of soils and their capacity to function to be recorded efficiently and monitored long term. They emphasise that it also serves as an important early warning system; with its help, it will be possible to identify, at an early stage, whether existing nature conservation goals can be achieved with current measures. | Climate | 2,021 |
January 14, 2021 | https://www.sciencedaily.com/releases/2021/01/210114163858.htm | Greenland melting likely increased by bacteria in sediment | Bacteria are likely triggering greater melting on the Greenland ice sheet, possibly increasing the island's contribution to sea-level rise, according to Rutgers scientists. | That's because the microbes cause sunlight-absorbing sediment to clump together and accumulate in the meltwater streams, according to a Rutgers-led study -- the first of its kind -- in the journal "These streams can be seen all over Greenland and they have a brilliant blue color, which leads to further melting since they absorb more sunlight than the surrounding ice," said lead author Sasha Leidman, a graduate student in the lab of co-author Asa K. Rennermalm, an associate professor in the Department of Geography in the School of Arts and Sciences at Rutgers University-New Brunswick. "This is exacerbated as dark sediment accumulates in these streams, absorbing even more sunlight and causing more melting that may increase sea-level rise."The Greenland ice sheet covers about 656,000 square miles -- most of the island and three times the size of Texas, according to the National Snow & Ice Data Center. The global sea level would rise an estimated 20 feet if the thick ice sheet melted.With climate change, sea-level rise and coastal storms threaten low-lying islands, cities and lands around the world.Most scientists ignore sediment in glacial streams that form on top of the Greenland ice sheet as meltwater flows to the ocean, but the Rutgers-led team wanted to find out why they accumulated so much sediment. In 2017, scientists flew drones over an approximately 425-foot-long stream in southwest Greenland, took measurements and collected sediment samples. They found that sediment covers up to a quarter of the stream bottom, far more than the estimated 1.2 percent that would exist if organic matter and cyanobacteria did not cause sediment granules to clump together. They also showed that streams have more sediment than predicted by hydrological models."We found that the only way for sediment to accumulate in these streams was if bacteria grew in the sediment, causing it to clump into balls 91 times their original size," Leidman said. "If bacteria didn't grow in the sediment, all the sediment would be washed away and these streams would absorb significantly less sunlight. This sediment aggregation process has been going on for longer than human history."The solar energy absorbed by streams likely depends on the health and longevity of the bacteria, and further warming in Greenland may lead to greater sediment deposits in glacial streams, the study says."Decreases in cloud cover and increases in temperature in Greenland are likely causing these bacteria to grow more extensively, causing more sediment-driven melting," Leidman said. "With climate change causing more of the ice sheet to be covered by streams, this feedback may lead to an increase in Greenland's contribution to sea-level rise. By incorporating this process into climate models, we'll be able to more accurately predict how much melting will occur, with the caveat that it is uncertain how much more melting will take place compared with what climate models predict. It will likely not be negligible." | Climate | 2,021 |
January 14, 2021 | https://www.sciencedaily.com/releases/2021/01/210114130153.htm | Accounting for the gaps in ancient food webs | If you want to understand an ecosystem, look at what the species within it eat. In studying food webs -- how animals and plants in a community are connected through their dietary preferences -- ecologists can piece together how energy flows through an ecosystem and how stable it is to climate change and other disturbances. Studying ancient food webs can help scientists reconstruct communities of species, many long extinct, and even use those insights to figure out how modern-day communities might change in the future. There's just one problem: only some species left enough of a trace for scientists to find eons later, leaving large gaps in the fossil record -- and researchers' ability to piece together the food webs from the past. | "When things die and get preserved as fossils, all the stuff that isn't bones and teeth and shells just decays," says the Santa Fe Institute's Vice President for Science Jennifer Dunne, a veteran food web researcher. "Organisms that are primarily soft-bodied, they usually just disappear from the record altogether."A new paper by paleoecologist Jack Shaw, a PhD student at Yale University who led the study, Dunne and other researchers shines a light on those gaps and points the way to how to account for them. "The missing components of the fossil record -- such as soft-bodied organisms -- represent huge gaps in understanding ancient ecology, but we haven't thought extensively about how those gaps are affecting our inferences," Shaw says. "We're taking the fossil record at face value without critically thinking about how face value might not be robust and accurate."Focusing on the absence of soft-bodied taxa in the fossil record, the study, published in But by drawing on network theory, the researchers were able to show that the inclusion of soft-bodied organisms is vital for realistic depictions of ancient food webs. They found that ecological differences between soft- and hard-bodied taxa appear in the record of an Early Eocene food web, but not in much older Cambrian food webs, suggesting that the differences between the groups have existed for at least 48 million years."Geologists and biologists assume that soft-bodied and hard-bodied things have distinct life habits -- where they live or who they eat -- but we actually quantify it here using network analysis," Shaw says.He and Dunne hope the study will help strengthen future research in the burgeoning field of ancient food web reconstruction. "This work is really important, because it's grappling with some of the fundamental uncertainty relating to the fossil record," says Dunne."The methodology can be applied to various other types of biases," not just the soft-bodied organism related bias, Shaw notes. "We're hoping to start being more critical of ancient food webs and perhaps opening them up to being more robust. A better grasp on how ancient food webs were affected by perturbations will allow us to make better predictions of what future ecosystems may look like." | Climate | 2,021 |
January 14, 2021 | https://www.sciencedaily.com/releases/2021/01/210114130128.htm | New classification marks paradigm shift in how conservationists tackle climate change | A new study co-authored by researchers from the Wildlife Conservation Society's (WCS) Global Conservation Program and the University of British Columbia (UBC) Faculty of Forestry introduces a classification called Resistance-Resilience-Transformation (RRT) that enables the assessment of whether and to what extent a management shift toward transformative action is occurring in conservation. The team applied this classification to 104 climate adaptation projects funded by the WCS Climate Adaptation Fund over the past decade and found differential responses toward transformation over time and across ecosystems, with more transformative actions applied in forested ecosystems. | The RRT classification addresses a continuum from actively resisting changes -- in order to maintain current or historical conditions -- through accelerating ecological transitions through approaches such as translocating species to new areas. Results show a shift from more resistance-type actions to transformative ones in recent years. Most transformation-oriented projects involved translocation of trees or other plants, commonly in forest ecosystems, with exceptions including, for example, translocating seabird species to habitat where they may be more likely to survive. Other ecosystems with more transformative projects occurred in coastal aquatic and urban/suburban ecosystems.Unprecedented environmental changes such as increased frequency and severity of heatwaves, droughts, storms, heavy rainfalls, and wildfires, have degraded ecosystems, disturbed the economy, and led to the loss of lives and livelihoods. Conventional conservation strategies may be ineffective in dealing with changing environmental conditions: wildfires could decimate protected old-growth forests and endangered species, and coastal conservation easements could become inundated by rising seas. Novel conservation actions aimed specifically at helping ecosystems adapt to the mounting impacts of climate change contrast with approaches that aim to maintain current or historical conditions. Transformative actions, such as species translocation, were once more controversial than they are today; they are now increasingly highlighted as necessary components of conservation in an effort to implement projects that are more robust to future climates. However, few studies have systematically examined on-the-ground conservation adaptation projects to assess the extent to which such transformational adaptation actions are being implemented, through what approaches, and in what ecosystems.This study, published in The interdisciplinary research team was supported by the Doris Duke Charitable Foundation, and the study was conducted in partnership with the IUCN Species Survival Commission's Climate Change Specialist Group.Precautionary actions aimed at resistance or resilience -- such as protecting intact ecosystems -- are incredibly valuable in the suite of responses needed to address current and future climate change. But the authors suggest that degraded ecosystems or working landscapes may require more transformative actions and the public support to do so, in an effort to meet the shifting goals in a changing climate. This research provides evidence of a paradigm shift, as practitioners and funders move more in this critical direction. | Climate | 2,021 |
January 14, 2021 | https://www.sciencedaily.com/releases/2021/01/210114085436.htm | Climate change is hurting children's diets, global study finds | A first-of-its-kind, international study of 107,000 children finds that higher temperatures are an equal or even greater contributor to child malnutrition and low quality diets than the traditional culprits of poverty, inadequate sanitation, and poor education. | The 19-nation study is the largest investigation of the relationship between our changing climate and children's diet diversity to date. It is believed to be the first study across multiple nations and continents of how both higher temperatures and rainfall -- two key results of climate change -- have impacted children's diet diversity."Certainly, future climate changes have been predicted to affect malnutrition, but it surprised us that higher temperatures are already showing an impact," said lead author Meredith Niles, an assistant professor of Nutrition and Food Sciences at the University of Vermont and a fellow at the university's Gund Institute for Environment.Led by University of Vermont researchers, the study examines diet diversity among 107,000 children 5 and under in 19 countries in Asia, Africa, and South America, using 30 years of geo-coded temperature and precipitation data, and socioeconomic, ecological, and geographic data.The study finds that the negative effects of climate -- especially higher temperature -- on diet diversity are greater in some regions than the positive effects of education, water and sanitation and poverty alleviation -- all common global development tactics. The findings were published today in Of the six regions examined -- Asia; Central and South America; North, West, and Southeast Africa, five had significant reductions in diet diversity associated with higher temperatures.Researchers focused on diet diversity, a metric developed by the United Nations to measure diet quality and micronutrient intake. Micronutrients, such as iron, folic acid, zinc, and vitamins A and D, are critical for child development. A lack of micronutrients is a cause of malnutrition, which affects one out of every three children under the age of five. Diet diversity is measured by counting the number of food groups eaten over a given time period.On average, children in the study had eaten food from 3.2 food groups (out of 10) -- including meat and fish, legumes, dark leafy greens and cereal greens -- in the previous 24 hours. By contrast, diet diversity in emerging economies or more affluent countries such as China have been more than double this average (6.8 for children 6 and under)."Diet diversity was already low for this group," said UVM co-author Brendan Fisher. "These results suggest that, if we don't adapt, climate change could further erode a diet that already isn't meeting adequate child micronutrient levels."Severe childhood malnutrition is a significant global challenge. According to the United Nations, 144 million children under age 5 were affected by stunting in 2019, an effect of chronic malnutrition. In 2019, 47 million children under 5 suffered from wasting, or acute undernutrition the UN says, a condition caused by limited nutrient intake and infection.The study also found that higher precipitation, another potential effect of climate change in some regions, was associated with higher child diet diversity. In some cases, the effect of higher precipitation had a greater impact on child diet diversity than education, improved sanitation or greater forest cover."Higher rainfall in the future may provide important diet quality benefits in multiple ways, but it also depends on how that rain comes," said co-author Molly Brown of the University of Maryland. "If it's more erratic and intense, as is predicted with climate change, this may not hold true."The study builds on UVM global research into how nature improves both children's health, their diets, and human well-being. The findings suggest that, in addition to addressing current needs, policy makers need to plan for improving diets across the most vulnerable in the future with a warming climate in mind."A warming climate has the potential undermine all the good that international development programs provide," said co-author Taylor Ricketts, Director of UVM's Gund Institute for Environment. "In fact, that is something we find again and again in this global research: continued environmental degradation has the potential to undermine the impressive global health gains of the last 50 years."The research team included Meredith Niles, Taylor Ricketts, Brendan Fisher and Serge Wiltshire (University of Vermont), Molly Brown (University of Maryland), and Benjamin Emery (Sandia National Laboratories). | Climate | 2,021 |
January 14, 2021 | https://www.sciencedaily.com/releases/2021/01/210114085420.htm | Human-induced climate change caused the northwestern Pacific warming record in August 2020 | August 2020 set new record high sea surface temperatures (SSTs) in the northwestern Pacific Ocean and around the Japan coasts. A new study led by National Institute for Environmental Studies (NIES) researchers revealed that this warming record could not happen without human-induced climate changes. | The northwestern Pacific sea surface becomes warm seasonally around August every year. However, it was unprecedentedly high in August 2020, according to the Japan Meteorological Agency and the National Oceanic and Atmospheric Administration. The extremely high SSTs exceeding 30°C, which lasted until mid-September, may have intensified tropical cyclones such as Typhoon Haisheng, causing severe damages to the East Asian countries. Although human-induced greenhouse gas emissions such as carbon dioxide have gradually warmed the northwestern Pacific Ocean since the mid-20th century, it remains unclear yet how much past human activities may increase the occurrence likelihood of such regional record-warm SSTs."Understanding the tropical warm water expansion in the Indo-Pacific and Atlantic Oceans is essential for projecting changes in the characteristics of tropical cyclones and other weather events in the future," said Hideo Shiogama, a co-author and the head of Climate Risk Assessment Section at the Center for Global Environmental Research, NIES. "A quantitative evaluation of what drives regional extreme temperatures happening recently is necessary to take appropriate measures to reduce greenhouse gas emissions and the impacts of global warming."The paper published in "The numerical climate model ensembles are powerful tools to quantitatively distinguish between natural variability of the Earth system and climate changes caused by human activities," said corresponding lead author Michiya Hayashi, a research associate at NIES. The ensemble of 31 climate models participating in the sixth phase of the Coupled Model Intercomparison Project (CMIP6) consists of a series of historical experiments and future scenario experiments forced by greenhouse gas- and aerosol emissions from human activities and natural volcanic and solar variations from 1850 to 2100. "We can compare the historical and future experiments with a sub-ensemble of the CMIP6 climate models forced only by the natural volcanic and solar activities to estimate to what extent human-caused climate changes have altered the northwestern Pacific Ocean condition until today.""The northwestern Pacific warming has proceeded clearly since the 1980s," stated Shiogama. "The warming speed has been accelerated in the last four decades as the reduced aerosol emissions do not cancel the warming signal forced by increasing greenhouse gas concentration anymore." The results show that the CMIP6 ensemble well reproduces the observed long-term change in the northwestern Pacific August SST within the range of 'once-in-20-year' events in the historical simulations. "The SSTs that exceed the pre-industrial range are rarely observed during the 20th century but have occurred frequently since 2010, indicating that human influences on the northwestern Pacific Ocean are already detectable in observations," noted a co-author Seita Emori, deputy director of the Center for Global Environmental Research at NIES.This new study estimates that the occurrence frequency of high northwestern Pacific SSTs exceeding the August 2020 level has been increased from once-in-600 years in the 20th century (1901-2000) to once-in-15 years in the present climate (2001-2020) using the CMIP6 ensemble. On the other hand, in the sub-ensemble forced only by natural volcanic and solar activities, the frequency for 2001-2020 is estimated to be once-in-1000 years or less. "The record high level of the northwestern Pacific SST in August could have occurred approximately once per 15 years in 2001-2020, as observed, but it never likely occurred without human-induced greenhouse gases or in the 20th century," said Hayashi.Importantly, the scientists also imply from the future scenario experiments that the 2020 record high SST is becoming a new normal climate condition in August at the northwestern Pacific region by 2031-2050 when the globally averaged air temperature relative to pre-industrial levels would exceed 1.5°C. In this case, the tropical warm sea surface water, exceeding 28°C, may reach Japan, the Korean Peninsula, the west coast of India, the east coast of the U.S. mainland, and the west of the Hawaiian Islands. "We might need to prepare for living with such warm ocean conditions even if we humans could achieve the 1.5°C goal of the Paris Agreement," said Hayashi."The human-induced ocean warming may have impacted tropical cyclones, heavy rainfall, and marine life from the past to present and will continue in the future unless tremendous mitigation measures would be implemented," added Emori. "It is time to take prompt actions to transform our society for reducing the greenhouse gas emissions and for adapting to a changing climate." | Climate | 2,021 |
January 14, 2021 | https://www.sciencedaily.com/releases/2021/01/210114085411.htm | Scientists discover the secret of Galápagos' rich ecosystem | New research has unlocked the mystery of how the Galápagos Islands, a rocky, volcanic outcrop, with only modest rainfall and vegetation, is able to sustain its unique wildlife habitats. | The Galápagos archipelago, rising from the eastern equatorial Pacific Ocean some 900 kilometres off the South American mainland, is an iconic and globally significant biological hotspot. The islands are renowned for their unique wealth of endemic species, which inspired Charles Darwin's theory of evolution and today underpins one of the largest UNESCO World Heritage Sites and Marine Reserves on Earth.Scientists have known for decades that the regional ecosystem is sustained by upwelling of cool, nutrient-rich deep waters, which fuel the growth of the phytoplankton upon which the entire ecosystem thrives.Yet despite its critical life-supporting role, the upwelling's controlling factors had remained undetermined prior to this new study. Establishing these controls, and their climate sensitivity, is critical to assessing the resilience of the regional ecosystem against modern climatic change.In this new research, published in This model showed that the intensity of upwelling around the Galápagos is driven by local northward winds, which generate vigorous turbulence at upper-ocean fronts to the west of the islands. These fronts are areas of sharp lateral contrasts in ocean temperature, similar in character to atmospheric fronts in weather maps, but much smaller.The turbulence drives upwelling of deep waters toward the ocean surface, thus providing the nutrients needed to sustain the Galápagos ecosystem.Alex Forryan of the University of Southampton, who performed the research, said: "Our findings show that Galápagos upwelling is controlled by highly localised atmosphere-ocean interactions. There now needs to be a focus on these processes when monitoring how the islands' ecosystem is changing, and in mitigating the ecosystem's vulnerability to 21st -century climate change."Professor Alberto Naveira Garabato, also of the University of Southampton, who led the project supporting the research, said: "This new knowledge of where and how the injection of deep-ocean nutrients to the Galapagos ecosystem happens is informing ongoing plans to expand the Galápagos Marine Reserve, and improve its management against the mounting pressures of climate change and human exploitation." | Climate | 2,021 |
January 14, 2021 | https://www.sciencedaily.com/releases/2021/01/210114111922.htm | Scientists reduce uncertainty in forest carbon storage calculations | Investors who bet on tropical forest conservation and reforestation to solve global warming by storing carbon in wood face huge uncertainties because the science behind predicting carbon stocks is still shaky. Even the best Earth Systems Models fail to predict how carbon stored by tropical forests varies from place to place. The | She worked with Kristina Anderson-Teixeira, also a STRI staff scientist at STRI's Center for Tropical Forest Science-Forest Global Earth Observatory (Smithsonian ForestGEO), post-doctoral fellows from Columbia University and Princeton University, and two STRI interns to sift through dozens of studies to synthesize patterns of how tropical forest productivity and carbon storage varies across the globe. They conclude that warm, wet tropical forests with moderately fertile soils store more carbon."Ecologists have been studying tropical forests for over a hundred years," said Muller-Landau, "but most studies focus on a single forest type or a single region, making it hard to see the big picture of how carbon flows through forests. We lacked a synthesis of how tropical forests vary with climate, soils, and disturbance regime, and of what we know about the mechanisms underlying this variation."The authors gathered studies from tropical forests around the world that measured variables such as carbon stocks, forest productivity and carbon residence time in eight or more sites differing in temperature, precipitation, elevation, and/or soil fertility. STRI interns Eva Arroyo and Bogumila Backiel contributed to the literature review and analyses.KC Cushman, a post-doctoral fellow with funding from the Next Generation Ecosystem Experiments-Tropics, U.S. Department of Energy, Office of Science, Office of Biological and Environmental Research determined the geographical location of each study and obtained climate information for every site from the global CHELSA climate datasets so the team could evaluate the ranges of climate variables for all of the studies."One of the challenges is that the older studies don't estimate carbon or report results in terms of carbon," Cushman said. "But they often report other quantities that are reasonably good proxies; for example, canopy height is a good predictor of forest carbon stocks."Some big take-away's emerged: In wet tropical forests, trees grow faster and store more carbon than in drier forests. Low elevation forests are taller and store more carbon than high elevation forests.And when soils are more fertile, trees are more productive, which would, all else being equal, be expected to lead to higher carbon stocks. But when soils are more fertile, trees also die faster, which, on its own, would lead to decreasing carbon stocks with higher fertility. But putting those two things together, carbon stocks should be greatest at intermediate fertility, which would explain why previous studies do not agree upon whether carbon stocks increase or decrease with soil fertility.Another big takeaway is that little is known about tree mortality, even though it is essential for predicting carbon stocks. In areas where the forest is disturbed more often, or tree mortality is higher for other reasons, less carbon is stored as biomass, and it flows through the system faster.Although the patterns of carbon storage in tropical forests differ from place to place, the general patterns are surprisingly consistent. African and Asian tropical forests have higher biomass in areas where the climate is similar to that in American forests, for example. Certainly, there are important exceptions to the rules-for example, some high-elevation forests are very high in biomass. But the exceptions help researchers to identify the general mechanisms underlying these patterns.As she began the review, Muller-Landau consulted former STRI staff scientist Egbert Leigh's classic text Tropical Forest Ecology, for a summary of general understanding before her synthesis. Leigh noted that dry forests (those with dry seasons of 5 or more months) had lower productivity and biomass, but considered all other lowland forests, including those with shorter dry seasons as well as ever-wet forests, to have similar leaf productivity, mortality and biomass. Her new synthesis shows that, in fact, there is a lot of variation among these forests, and that this variation is structured by climate and soils, with broadly consistent relationships across regions."This synthesis enormously widens our sense of how above-ground carbon stocks vary with climate and soil fertility," Leigh said when asked to comment, "and makes it much easier to ask questions about the causes of these relationships." | Climate | 2,021 |
January 13, 2021 | https://www.sciencedaily.com/releases/2021/01/210113144507.htm | Resilience to climate change? octopuses adapting to higher ocean acid levels | With the impact of climate change increasing by the day, scientists are studying the ways in which human behavior contributes to the damage. A recent study at Walla Walla University, by a collaboration of researchers from Walla Walla University and La Sierra University, examined the effects of acidic water on octopuses, potentially bringing new insight into both how our activities impact the world around us, and the way that world is adapting in response. | The study, "Impact of Short- and Long-Term Exposure to Elevated Seawater PCOInitial work in the field focused on the negative effects of ocean acidity: the impaired growth of affected species such as hermit crabs, for example, or reduced survival rates of certain types of fish over time. Adaptability, however, has not received as much attention, particularly when it comes to octopuses and other cephalopods. What studies have been conducted showed conflicting results, particularly when it comes to short-term vs. long-term exposure to increased ocean acidity (OA).For instance, studies on cuttlefish show no significant change in their metabolism after exposure to increased OA, while squid subjected to the same conditions showed a reduction in aerobic metabolism, indicating reduced oxygen circulation in the subjects.For purposes of this experiment, researchers used octopus rubescens a small and easily maintained species of octopus common to the west coast of North America. The subjects were exposed to increased COMetabolic rates are very telling in such circumstances because most significant physiological changes -- such as smaller organs or reduced growth -- are reflected in the shift in metabolism. (Changes in physiology are essentially changes in energy use, which can be observed by monitoring metabolism.)The results demonstrated a surprising amount of adaptability in the subjects, as well as possible causes for data variation in other experiments. The subjects experienced high levels of metabolic change within the first 24 hours of exposure to increased acidity: a departure from earlier studies on different cephalopods, which showed a decrease in metabolic change.However, when the same subjects were evaluated after one week, their RMR had returned to normal. The normal readings remained after 5 weeks as well, though their ability to function in low oxygen levels suffered in response to the increased acidity.The results suggest that octopuses may be better able to withstand changes in ocean-acidity levels, which may have long-term bearings on our understanding of climate change. It also marks the first study to compare long-term and short-term effects of increased acid exposure. Further research is needed to clarify the mechanism driving the change in RMR, but the experimental parameters -- and the use of octopus rubescens as test subjects -- provide an excellent model system for studying the effects of OA on cephalopods. | Climate | 2,021 |
January 13, 2021 | https://www.sciencedaily.com/releases/2021/01/210113144505.htm | Taking the lab into the ocean: A fleet of robots tracks and monitors microbial communities | Researchers from MBARI, the University of Hawai'i at M?noa (UH M?noa), and Woods Hole Oceanographic Institution, after years of development and testing, have successfully demonstrated that a fleet of autonomous robots can track and study a moving microbial community in an open-ocean eddy. The results of this research effort were recently published in | Autonomous robotic fleets enable researchers to observe complex systems in ways that are otherwise impossible with purely ship-based or remote sensing techniques. In a time when the COVID-19 pandemic is reducing opportunities for researchers to go to sea, autonomous fleets offer an effective way to maintain a persistent presence in features of interest.Oceanic microbes are essential players in the global climate system, producing roughly half of the world's oxygen, removing carbon dioxide, and forming the base of the marine food web. Open-ocean eddies can be over 100 kilometers (62 miles) across and last for months. Phytoplankton (a kind of microscopic algae) thrive when these eddies spin counterclockwise in the Northern Hemisphere and bring nutrient-rich water from the depths up toward the surface."The research challenge facing our interdisciplinary team of scientists and engineers was to figure out a way to enable a team of robots -- communicating with us and each other -- to track and sample the DCM," said Brett Hobson, a senior mechanical engineer at MBARI and a coauthor of this study. Researchers have struggled to study the DCM because at depths of more than 100 meters (328 feet), it can't be tracked with remote sensing from satellites. Moreover, the position of the DCM can shift more than 30 meters (98 feet) vertically in just a few hours. This variability in time and space requires technology that can embed itself in and around the DCM and follow the microbial community as it drifts in the ocean currents.Ed DeLong and David Karl, oceanography professors in the UH M?noa School of Ocean and Earth Science and Technology (SOEST) and co-authors of the study, have been researching these microbes for decades. DeLong noted that these teams of coordinated robotic vehicles offer a vital step toward autonomous and adaptive sampling of oceanographic features. "Open-ocean eddies can have a huge impact on microbes, but until now we haven't been able to observe them in this moving frame of reference," he explained.During the Simons Collaboration on Ocean Processes and Ecology (SCOPE) Eddy Experiment in March and April 2018, researchers used satellite imaging to locate an eddy north of the Hawaiian Islands. They deployed a hi-tech team of three robots -- two long-range autonomous underwater vehicles (LRAUVs) and one Wave Glider surface vehicle -- from the Schmidt Ocean Institute's (SOI) research vessel Falkor.The first LRAUV (named Aku) acted as the primary sampling robot. It was programmed to locate, track, and sample the DCM. Using an onboard 3rd-Generation Environmental Sample Processor (3G-ESP), Aku filtered and preserved seawater samples, allowing researchers to capture a series of snapshots of the organisms' genetic material and proteins.The second LRAUV (named Opah) acoustically tracked Aku and spiraled vertically around it to collect crucial information about the environment surrounding the DCM. LRAUVs Aku and Opah carried a suite of sensors to measure temperature, salinity, depth, dissolved oxygen, chlorophyll concentrations, optical backscatter, and photosynthetically active radiation. Aku remained submerged for several days at a time sampling the DCM, while Opah surfaced every few hours to relay information via satellite back to scientists on the ship. A Wave Glider surface robot (named Mola) also tracked Aku with sonar and communicated with the science team aboard the Falkor."This work is really the fulfillment of a decades-long vision," said MBARI President and CEO Chris Scholin. Scholin has been engaged in this effort since he was an MBARI postdoctoral researcher seeking to develop autonomous sampling technology for marine systems. "Coordinating a robotic fleet to show how microbial communities react to changing conditions is a game-changer when it comes to oceanographic research."The researchers determined that Aku accurately and consistently tracked the DCM over the course of its multi-day sampling missions. By tracking the temperature corresponding to the peak of chlorophyll (an indicator of phytoplankton) in the DCM, the LRAUV maintained its position within the DCM even as this biological feature moved as much as 36 meters (118 feet) vertically in four hours."Building an LRAUV with an integrated ESP that could track this feature was a milestone. Combining that sampling power with the agility of three different robots autonomously working together over the course of the experiment is a significant engineering and operations achievement," said Yanwu Zhang, a senior research engineer at MBARI and the lead author of this study.Beyond the extraordinary engineering feat of organizing this robot ballet, the study also offers key takeaways related to how the biological community behaves inside a swirling eddy. RNA measurements reveal that as the eddy weakened into the second leg of the experiment, the phytoplankton biomass in the DCM decreased. "Much like our own team of researchers, each of the robots in the fleet is a specialist contributing to the experiment," said John Ryan, a senior research specialist at MBARI and a coauthor of the study. "This adaptive approach gives us a new perspective on the environmental processes going on inside and around this plankton community."These robotic fleets are now also being used to monitor other key disturbances to ocean health like harmful algal blooms and oil spills. "Given the rapid changes our ocean is undergoing as a result of human activities such as climate change, pollution and overfishing, this technology has the potential to transform our ability to understand and predict ocean health," said Scholin.This research is supported by the National Science Foundation, the Simons Foundation, the Gordon and Betty Moore Foundation, the Schmidt Ocean Institute, the David and Lucile Packard Foundation, and the State of Hawai'i. | Climate | 2,021 |
January 13, 2021 | https://www.sciencedaily.com/releases/2021/01/210113144456.htm | Earth to reach temperature tipping point in next 20 to 30 years, new study finds | Earth's ability to absorb nearly a third of human-caused carbon emissions through plants could be halved within the next two decades at the current rate of warming, according to a new study in | The terrestrial biosphere -- the activity of land plants and soil microbes -- does much of Earth's "breathing," exchanging carbon dioxide and oxygen. Ecosystems across the globe pull in carbon dioxide through photosynthesis and release it back to the atmosphere via the respiration of microbes and plants. Over the past few decades, the biosphere has generally taken in more carbon than it has released, mitigating climate change.But as record-breaking temperatures continue to spread across the globe, this may not continue; the NAU, Woodwell Climate and Waikato researchers have detected a temperature threshold beyond which plant carbon uptake slows and carbon release accelerates.Lead author Katharyn Duffy, a postdoctoral researcher at NAU, noticed sharp declines in photosynthesis above this temperature threshold in nearly every biome across the globe, even after removing other effects such as water and sunlight."The Earth has a steadily growing fever, and much like the human body, we know every biological process has a range of temperatures at which it performs optimally, and ones above which function deteriorates," Duffy said. "So, we wanted to ask, how much can plants withstand?"This study is the first to detect a temperature threshold for photosynthesis from observational data at a global scale. While temperature thresholds for photosynthesis and respiration have been studied in the lab, the Fluxnet data provide a window into what ecosystems across Earth are actually experiencing and how they are responding."We know that the temperature optima for humans lie around 37 degrees Celsius (98 degrees Fahrenheit), but we in the scientific community didn't know what those optima were for the terrestrial biosphere," Duffy said.She teamed up with researchers at Woodwell Climate and the University of Waikato who recently developed a new approach to answer that question: MacroMolecular Rate Theory (MMRT). With its basis in the principles of thermodynamics, MMRT allowed the researchers to generate temperature curves for every major biome and the globe.The results were alarming.The researchers found that temperature "peaks" for carbon uptake -- 18 degrees C for the more widespread C3 plants and 28 degrees C for C4 plants -- are already being exceeded in nature, but saw no temperature check on respiration. This means that in many biomes, continued warming will cause photosynthesis to decline while respiration rates rise exponentially, tipping the balance of ecosystems from carbon sink to carbon source and accelerating climate change."Different types of plants vary in the details of their temperature responses, but all show declines in photosynthesis when it gets too warm," said NAU co-author George Koch.Right now, less than 10 percent of the terrestrial biosphere experiences temperatures beyond this photosynthetic maximum. But at the current rate of emissions, up to half the terrestrial biosphere could experience temperatures beyond that productivity threshold by mid-century -- and some of the most carbon-rich biomes in the world, including tropical rainforests in the Amazon and Southeast Asia and the Taiga in Russia and Canada, will be among the first to hit that tipping point."The most striking thing our analysis showed is that the temperature optima for photosynthesis in all ecosystems were so low," said Vic Arcus, a biologist at the University of Waikato and co-author of the study. "Combined with the increased rate of ecosystem respiration across the temperatures we observed, our findings suggest that any temperature increase above 18 degrees C is potentially detrimental to the terrestrial carbon sink. Without curbing warming to remain at or below the levels established in the Paris Climate Accord, the land carbon sink will not continue to offset our emissions and buy us time."Funding for this research was provided by the National Aeronautics and Space Administration (grant NNX12AK12G), National Science Foundation (NSF) East-Asia Pacific Summer Institute Fellowship (1614404), the Royal Society of New Zealand Foreign Partnership Programme (EAP- UOW1601) and the New Zealand Marsden Fund (grant 16-UOW-027). This work used eddy covariance data acquired and shared by the FLUXNET community, including AmeriFlux, AfriFlux, AsiaFlux, CarboAfrica, CarboEuropeIP, CarboItaly, CarboMont, ChinaFlux, Fluxnet-Canada, GreenGrass, ICOS, KoFlux, LBA, NECC, OzFlux-TERN, TCOS-Siberia and USCCC networks. | Climate | 2,021 |
January 13, 2021 | https://www.sciencedaily.com/releases/2021/01/210113144428.htm | Physical weathering of rock breakdown more important than previously recognized | Research led by the University of Wyoming shows that physical weathering is far more important than previously recognized in the breakdown of rock in mountain landscapes. Because it is difficult to measure, physical weathering has commonly been assumed to be negligible in previous studies. | Cliff Riebe, a professor in UW's Department of Geology and Geophysics, headed a research group that discovered that climate and erosion rates strongly regulate the relative importance of subsurface physical and chemical weathering of saprolite, the zone of weathered rock that retains the relative positions of mineral grains of the parent bedrock and lies between the layer of soil and harder rock underneath. Saprolite is much like the weathered granite found on the flat areas surrounding the hard granite of Vedauwoo."Our work shows that physical strain can no longer be ignored in studies of subsurface weathering. It's not just a chemical process. It is physical as well," Riebe says. "What we found is that anisovolumetric weathering is much more common than previously thought, and that variations in this process can be explained by climate and erosion."Riebe is lead author of a paper, titled "Anisovolumetric Weathering in Granitic Saprolite Controlled by Climate and Erosion Rates," which was published in the Jan. 12 issue of The study looked at three sites -- with differing climates and elevations of granitic bedrock -- of the Sierra Nevada, a mountain range in California.In the lingo of geochemists, weathering has long been assumed to be "isovolumetric," meaning without a change in volume caused by physical strain."Our work shows that, to the contrary, weathering is commonly 'anisovolumetric,' meaning that strain caused by physical weathering is important," Riebe says.Riebe credits some of the tools and instruments that were purchased from the Wyoming Center for Environmental Hydrology and Geophysics (WyCEHG) EPSCoR (Established Program to Stimulate Competitive Research) project that ended a few years ago as the reason his team could measure both physical and chemical weathering at several sites in California."The reason why weathering was difficult to measure in the past is you have to be able to access the deep subsurface and sample it without disturbing it," Riebe explains. "You need a Geoprobe push coring system, which is basically a big track-mounted drill rig, to do this."It's expensive work, especially if you do not happen to own a Geoprobe and have to hire someone to do the work," he continues. "Fortunately, we have access to this equipment and the expertise to operate it through Wyoming's Near Surface Geophysics facility, which is ably managed by Brad Carr, one of the study's co-authors."The research was funded by grants from the National Science Foundation (NSF), NASA and the Natural Sciences and Engineering Research Council of Canada.Riebe says there is a direct correlation between the research in this paper and the $5.33 million NSF grant he received last September. The grant focuses on connections among rock, water and life at Earth's surface."This research is partly supported by that grant and also helped inspire it," Riebe says. | Climate | 2,021 |
January 13, 2021 | https://www.sciencedaily.com/releases/2021/01/210113132413.htm | Study looks at how land acquisitions affect climate change | In 2007, an increase in world food prices led to a global rush for land in the form of land grabs or large-scale land acquisitions. Over the last two decades, such acquisitions have resulted in millions of hectares of land changing hands in developing nations. Although such changeover can increase the cultivation of crops needed to feed the world's growing population and spark new agricultural practices and technologies, it can also lead to environmental degradation, increased carbon emissions and threats to the livelihoods of smallholder farmers. | The socioeconomic and environmental consequences of such large-scale land acquisitions have been studied, but the effect of land grabs on carbon emissions has not, at least until now.In a newly published study in the journal "Overall, the findings suggest there is a cost-effective way to produce more food while minimizing carbon emissions from this process," said Chuan Liao, assistant professor in ASU's School of Sustainability and lead author of the study."It's unrealistic to say that we can't convert more land given that the world's population is growing especially in developing countries, but we still must minimize carbon emissions while pursuing agricultural development," he said.The study researchers analyzed countries that were engaged in over 1,000 transnational, large-scale land acquisitions. They identified three distinct geographic areas where land grabs take place including coastal West Africa and the East African Rift Valley; Southeast Asia; Central-South Latin America; and Eastern Europe and western Russia.The study showed that the quest for resources, like arable land and water, drives large-scale land acquisitions. That is, countries with low or medium-low arable land availability are usually investors, whereas those with medium-high or high arable land serve as hosts, said Liao. Likewise, countries with less water scarcity often supply land, whereas those countries with higher water scarcity invest in land.The researchers also estimated carbon emissions from nearly 1,500 cases of large-scale land acquisitions under two agricultural-development scenarios, including business as usual and enforcement of environmental regulations.In analyzing those emissions, the researchers found that the business-as-usual scenario, that is, clearing all vegetation from 37 million hectares of land, would emit approximately 2.26 gigatons of carbon. In contrast, implementing environmental regulations to constrain land conversion and save high-carbon-value forests would reduce emissions to 0.81 gigatons.The study also found that enforcing environmental regulation policies does not reduce the amount of land that can be used for agricultural development at the same proportion as the reduction in carbon emission."Instead, we allow agricultural development on lands that have lower carbon values," explained Liao. "Our strategy is to better manage these tradeoffs because food security and carbon emission mitigation are both important." | Climate | 2,021 |
January 13, 2021 | https://www.sciencedaily.com/releases/2021/01/210113120719.htm | Wetland methane cycling increased during ancient global warming event | Wetlands are the dominant natural source of atmospheric methane, a potent greenhouse gas which is second only to carbon dioxide in its importance to climate change. Anthropogenic climate change is expected to enhance methane emissions from wetlands, resulting in further warming. However, wetland methane feedbacks were not fully assessed in the Intergovernmental Panel on Climate Change (IPCC) Fifth Assessment Report, posing a challenge to meeting the global greenhouse gas mitigation goals set under the Paris Agreement. | To understand how wetland methane cycling may evolve and drive climate feedbacks in the future, scientists are increasingly looking to Earth's past."Ice core records indicate that atmospheric methane is very sensitive to climate, but we cannot measure atmospheric methane concentrations beyond them, prior to about 1 million years ago," said Dr Gordon Inglis, lead author and Royal Society Dorothy Hodgkin Fellow at the University of Southampton."Instead, we must rely on indirect 'proxies' preserved within the sedimentary record. Proxies are surrogates for climate variables that cannot be measured directly, including geochemical data stored in fossils, minerals or organic compounds."The study, which was published in The authors used a geochemical tool developed at the University of Bristol to analyse organic compounds made by microbes living in ancient soils and peats. During the PETM, they found the ratio of two carbon isotopes changed in these compounds -- a change that was likely due to an increased amount of methane in the microbes' diet."We show that the PETM was associated with an increase in wetland methane cycling; if some of this methane escaped into the atmosphere, it would have led to additional planetary warming. Crucially, this could foreshadow changes that the methane cycle will experience in the future due to anthropogenic emissions," said Dr Gordon Inglis."Our colleagues have previously shown the inclusion of methane emissions in climate model simulations is critical for interpreting past warmth. However, until recently, there have been no tools to test these predictions. This study confirms that methane cycling increased during the PETM, and perhaps during other warming events in Earth history," said Professor Rich Pancost, Head of the School of Earth Sciences at the University of Bristol.Intriguingly, proxies for temperature and methane cycling are only coupled at the onset of this ancient warming event, with the methane proxies rapidly returning to pre-event values even though temperatures remain high for the duration of the PETM. This suggests it is the onset of rapid global warming that is particularly disruptive to methane cycling in wetlands, a finding that is particularly concerning given the rapid global warming we are experiencing now. | Climate | 2,021 |
January 13, 2021 | https://www.sciencedaily.com/releases/2021/01/210113120704.htm | Pollinators not getting the 'buzz' they need in news coverage | A dramatic decline in bees and other pollinating insects presents a threat to the global food supply, yet it's getting little attention in mainstream news. That's the conclusion of a study from researchers at the University of Illinois Urbana-Champaign, published this week in a special issue of the | The study, titled "No buzz for bees," was led by Scott Althaus, the director of the U. of I. Cline Center for Advanced Social Research, and May Berenbaum, a leading expert on pollinator declines, head of Illinois' entomology department and one of three editors of the The research utilized the Cline Center's Global News Index, a unique database of millions of news items from thousands of global news sources, published over decades."No study like this, and certainly not at this scale, has ever been done before," said Althaus, also an expert on news coverage and its effects. "There simply has not been academic research on the evolving nature of news coverage given to pollinator declines, despite the importance of that topic within the scientific community."The study also analyzed decades of coverage in three English-language wire services based abroad: Agence France Presse, in France; Deutsche Presse Agentur, in Germany; and Xinhua General News Service, in China. Berenbaum, often described as an "ambassador for insects," initiated the project out of a desire to gauge public awareness of the pollinator-decline issue. She said she was startled by the results."As much as the entomological community is gripped by this impending crisis, it appears the public isn't paying much attention," she said. "It's not that people are indifferent, it's just that they don't even know about it." And they need to know about it, she said, because "it's a serious problem for everybody. Insects provide essential ecosystem services that people aren't aware of and take for granted, and for which we have no substitutes."The Cline Center researchers, including study co-authors Jenna Jordan and Dan Shalmon, found that the minimal amount of news coverage on pollinator decline that appeared in the six news outlets was concentrated in The New York Times and The Washington Post, and then most often was relegated to science or other specialty sections. Rarely did pollinator news appear on the front page, Althaus said. "It's not making it into the mainstream of public affairs news coverage. As we look at wire service reporting in the U.S., we hardly see any coverage of this topic at all."That was also true for the three English-language foreign-based wire services they looked at, Althaus said. "It's really difficult for us to know whether there might be specialty publications within these countries that are taking the issue up. But from what we can see for the broad-based wire service reporting, it is simply not on the radar screens of major news organizations in these other parts of the world."Since the vast majority of studies on pollinator decline have been done in Europe and North America, Berenbaum said, "we don't even know how serious the problem is. Most insect biodiversity, including pollinator diversity, is in the tropics."As for the factors contributing to pollinator decline, and insect decline generally, Berenbaum pointed to the introductory article for the special issue of On an individual level, Berenbaum said, "we can make a difference in the decisions we make about what flowers we plant in our gardens, which weeds we tolerate in our yards, even how we manage insect pests. A single backyard bug zapper, for instance, can kill tens of thousands of harmless insects over the course of a summer, including many pollinators, while killing barely a thimble-full of mosquitoes." | Climate | 2,021 |
January 13, 2021 | https://www.sciencedaily.com/releases/2021/01/210113120658.htm | Red and green snow algae increase snowmelt in the Antarctic Peninsula | Red and green algae that grow on snow in the Antarctic Peninsula (AP) cause significant extra snowmelt on par with melt from dust on snow in the Rocky Mountains, according to a first-of-its-kind scientific research study led by Alia Khan, affiliate research scientist at the National Snow and Ice Data Center (NSIDC) and assistant professor at Western Washington University. Algal blooms are likely to increase in Antarctica as the planet continues to warm, which will further exacerbate seasonal snowmelt and contribute to the expansion of ice-free areas in the AP region. This could have serious impacts on regional climate, snow and ice melt, freshwater availability and ecosystems, yet is not accounted for in current global climate models. Results of the research were published on January 13, 2021, in the European Geosciences Union's | "Warming along the Antarctic Peninsula is causing drastic changes in snow and ice melt, as well as ecosystem responses," said Khan. "We are seeing these algae blooms spread across wide areas along the coast. The blooms can be so intense and dark, like wearing a dark T-shirt on a sunny day, that they warm up the surface and cause more melting. The warming is likely expanding and strengthening the snow algae bloom season, which could continue to increase in this region of Antarctica as the climate continues to warm."The researchers investigated the impacts of red and green algae on albedo, which is how much light the surface of the snow reflects back to space, and radiative forcing, which is how much energy the surface absorbs. Darker surfaces decrease albedo and increase radiative forcing, and positive radiative forcing causes the planet to warm. This is the first time that radiative forcing effects from algae have been estimated in the AP region. The scientists conducted this research by taking ground-based spectral albedo measurements of red and green snow algae at three sites in January 2018 and then modeled the radiative forcing using historical multi-year measurements of solar radiation at Palmer Station in Antarctica. Two of the ground sites were on King George Island, north of Palmer Station, and one was on Nelson Island. Because algal blooms are linked to animal waste, which produces the nutrients that the algae need to grow, the researchers chose sites that seals, penguins and other birds frequent.When compared with clean snow, the scientists found that green algae patches reduce snow albedo by 40 percent, and red algae patches reduce albedo by 20 percent. Green snow algae contain more chlorophyll than red snow algae and therefore absorb more solar radiation, reducing albedo by a greater amount for the same concentration of algae in the snow. As a result, radiative forcing averages are twice as high for green patches compared with red patches. During peak growing season, in austral summer, the increase in radiative forcing is about 26 watts per square meter, and about 13 watts per square meters for red algae. These amounts of radiative forcing are comparable to those caused by dust on snow in the mid-latitudes, such as in the Rocky Mountains, which advances snowmelt there. In the AP, algal blooms result in about 3,700 cubic meters, or over a million gallons of additional snow melt per year."Antarctica is already an incredibly beautiful place, and snow algae blooms add an extra artistic dimension," said Ted Scambos, a polar researcher at the Cooperative Institute for Research in the Environmental Sciences (CIRES) at the University of Colorado Boulder and co-author of the study. "But like so many natural systems, the change in climate is pushing things to new extremes, with some unwanted consequences. We're seeing that these new darker and more widespread blooms are having a knock-on effect of accelerating melting, a feedback that makes the ice retreat a little faster."The results of this research show that snow algae play a significant role in snowmelt in the AP regions where they occur, and should be accounted for in future estimates of ice-free expansion in the AP region. Future research will focus on a wider mapping the spread of algae blooms, and on the climate events that create the most intense blooms. | Climate | 2,021 |
January 13, 2021 | https://www.sciencedaily.com/releases/2021/01/210113120656.htm | Melting icebergs key to sequence of an ice age | Scientists claim to have found the 'missing link' in the process that leads to an ice age on Earth. | Melting icebergs in the Antarctic are the key, say the team from Cardiff University, triggering a series of chain reactions that plunges Earth into a prolonged period of cold temperatures.The findings have been published today in It has long been known that ice age cycles are paced by periodic changes to Earth's orbit of the sun, which subsequently changes the amount of solar radiation that reaches the Earth's surface.However, up until now it has been a mystery as to how small variations in solar energy can trigger such dramatic shifts in the climate on Earth.In their study, the team propose that when the orbit of Earth around the sun is just right, Antarctic icebergs begin to melt further and further away from Antarctica, shifting huge volumes of freshwater away from the Southern Ocean and into the Atlantic Ocean.As the Southern Ocean gets saltier and the North Atlantic gets fresher, large-scale ocean circulation patterns begin to dramatically change, pulling CO2 out of the atmosphere and reducing the so-called greenhouse effect.This in turn pushes the Earth into ice age conditions.As part of their study the scientists used multiple techniques to reconstruct past climate conditions, which included identifying tiny fragments of Antarctic rock dropped in the open ocean by melting icebergs.The rock fragments were obtained from sediments recovered by the International Ocean Discovery Program (IODP) Expedition 361, representing over 1.6 million years of history and one of the longest detailed archives of Antarctic icebergs.The study found that these deposits, known as Ice-Rafted Debris, appeared to consistently lead to changes in deep ocean circulation, reconstructed from the chemistry of tiny deep-sea fossils called foraminifera.The team also used new climate model simulations to test their hypothesis, finding that huge volumes of freshwater could be moved by the icebergs.Lead author of the study Aidan Starr, from Cardiff University's School of Earth and Environmental Sciences, said: "We were astonished to find that this lead-lag relationship was present during the onset of every ice age for the last 1.6 million years. Such a leading role for the Southern Ocean and Antarctica in global climate has been speculated but seeing it so clearly in geological evidence was very exciting."Professor Ian Hall, co-author of the study and co-chief scientist of the IODP Expedition, also from the School of Earth and Environmental Sciences, said: "Our results provide the missing link into how Antarctica and the Southern Ocean responded to the natural rhythms of the climate system associated with our orbit around the sun."Over the past 3 million years the Earth has regularly plunged into ice age conditions, but at present is currently situated within an interglacial period where temperatures are warmer.However, due to the increased global temperatures resulting from anthropogenic CO2 emissions, the researchers suggest the natural rhythm of ice age cycles may be disrupted as the Southern Ocean will likely become too warm for Antarctic icebergs to travel far enough to trigger the changes in ocean circulation required for an ice age to develop.Professor Hall believes that the results can be used to understand how our climate may respond to anthropogenic climate change in the future."Likewise as we observe an increase in the mass loss from the Antarctic continent and iceberg activity in the Southern Ocean, resulting from warming associated with current human greenhouse-gas emissions, our study emphasises the importance of understanding iceberg trajectories and melt patterns in developing the most robust predictions of their future impact on ocean circulation and climate," he said.Professor Grant Bigg, from the University of Sheffield's Department of Geography, who contributed to the iceberg model simulations, said: "The groundbreaking modelling of icebergs within the climate model is crucial for identifying and supporting the ice-rafted debris hypothesis of Antarctic iceberg meltwater impacts which are leading glacial cycle onsets."The Cardiff University-led study was funded by NERC. | Climate | 2,021 |
January 13, 2021 | https://www.sciencedaily.com/releases/2021/01/210113100827.htm | Copper-indium oxide: A faster and cooler way to reduce our carbon footprint | Emergent e-fuel technologies often employ the reverse water-gas shift (RWGS) reaction to convert atmospheric CO | With ever-worsening climate change, there is a growing need for technologies that can capture and use up the atmospheric COTo tackle these problems, scientists developed a modified chemical-looping version of the RWGS reaction that converts COIn a recent study published in The scientists carried out X-ray-based analyses and found that the sample initially contained a parent material, Cu2InThe kinetics investigations provided further insights into the reaction. The reduction step revealed that Cu was responsible for the reduction of indium oxide at low temperatures, while the oxidation step showed that the Cu-In alloy surface preserved a highly reduced state while its bulk got oxidized. This allowed the oxidation to happen twice as quickly as that of other oxides. The team attributed this peculiar oxidation behavior to a rapid migration of negatively charged oxygen ions from the Cu-In alloy surface to its bulk, which assisted in the preferential bulk oxidation.The results have, quite expectedly, excited scientists about the future prospects of copper-indium oxides. "Given the current situation with carbon emission and global warming, a high-performance carbon dioxide conversion process is greatly desired. Although the chemically looped RWGS reaction works well with many oxide materials, our novel Cu-In-oxide here shows a remarkably higher performance than any of them. We hope that this will contribute significantly to reducing our carbon footprint and driving humankind towards a more sustainable future," concludes Sekine. | Climate | 2,021 |
January 13, 2021 | https://www.sciencedaily.com/releases/2021/01/210113090922.htm | Expert prognosis for the planet - we're on track for a ghastly future | A loss of biodiversity and accelerating climate change in the coming decades coupled with ignorance and inaction is threatening the survival of all species, including our very own, according to the experts from institutions including Stanford University, UCLA, and Flinders University. | The researchers state that world leaders need a 'cold shower' regarding the state of our environment, both to plan and act to avoid a ghastly future.Lead author Professor Corey Bradshaw of Flinders University in Australia says he and his colleagues have summarised the state of the natural world in stark form to help clarify the gravity of the human predicament."Humanity is causing a rapid loss of biodiversity and, with it, Earth's ability to support complex life. But the mainstream is having difficulty grasping the magnitude of this loss, despite the steady erosion of the fabric of human civilization" Professor Bradshaw says."In fact, the scale of the threats to the biosphere and all its lifeforms is so great that it is difficult to grasp for even well-informed experts."The problem is compounded by ignorance and short-term self-interest, with the pursuit of wealth and political interests stymying the action that is crucial for survival" he says.Professor Paul Ehrlich of Stanford University says that no political or economic system, or leadership, is prepared to handle the predicted disasters, or even capable of such action."Stopping biodiversity loss is nowhere close to the top of any country's priorities, trailing far behind other concerns such as employment, healthcare, economic growth, or currency stability."While it is positive news that President-elect Biden intends to reengage the US in Paris Climate accord within his first 100 days of office, it is a minuscule gesture given the scale of the challenge."Humanity is running an ecological Ponzi scheme in which society robs nature and future generations to pay for short-term economic enhancement today.""Most economies operate on the basis that counteraction now is too costly to be politically palatable. Combined with disinformation campaigns to protect short-term profits it is doubtful that the scale of changes we need will be made in time" Professor Ehrlich says.Professor Dan Blumstein from UCLA says the scientists are choosing to speak boldly and fearlessly because life literally depends on it."What we are saying might not be popular, and indeed is frightening. But we need to be candid, accurate, and honest if humanity is to understand the enormity of the challenges we face in creating a sustainable future."Without political will backed by tangible action that scales to the enormity of the problems facing us, the added stresses to human health, wealth, and well-being will perversely diminish our political capacity to mitigate the erosion of the Earth's life-support system upon which we all depend."Human population growth and consumption continues to escalate, and we're still more focused on expanding human enterprise than we are on devising and implementing solutions to critical issues such as biodiversity loss. By the time we fully comprehend the impact of ecological deterioration, it will be too late."Without fully appreciating and broadcasting the scale of the problems and the enormity of the solutions required, society will fail to achieve even modest sustainability goals, and catastrophe will surely follow" Professor Blumstein concludes.The experts say their 'perspective' paper, which cites more than 150 studies, seeks to outline clearly and unambiguously the likely future trends in biodiversity decline, mass extinction, climate disruption, planetary toxification, all tied to human consumption and population growth to demonstrate the near certainty that these problems will worsen over the coming decades, with negative impacts for centuries to come. It also explains the impact of political impotence and the ineffectiveness of current and planned actions to address the ominous scale of environmental erosion. | Climate | 2,021 |
January 12, 2021 | https://www.sciencedaily.com/releases/2021/01/210112173803.htm | No-till practices in vulnerable areas significantly reduce soil erosion | Soil erosion is a major challenge in agricultural production. It affects soil quality and carries nutrient sediments that pollute waterways. While soil erosion is a naturally occurring process, agricultural activities such as conventional tilling exacerbate it. Farmers implementing no-till practices can significantly reduce soil erosion rates, a new University of Illinois study shows. | Completely shifting to no-till would reduce soil loss and sediment yield by more than 70%, says Sanghyun Lee, doctoral student in the Department of Agricultural and Biological Engineering at U of I and lead author on the study, published in But even a partial change in tilling practices could have significant results, he adds."If we focus on the most vulnerable area in terms of soil erosion, then only 40% no-till shows almost the same reduction as 100% no-till implementation," Lee says.The study used physical data and computer modeling to estimate soil erosion in the Drummer Creek watershed, which is part of the Upper Sangamon River watershed in Central Illinois. The area's main crops are corn and soybeans, and tillage is a predominant agricultural practice."The rate of soil erosion is increased and accelerated by unsustainable agricultural production. One of the main reasons is conventional tillage in the field," Lee says. "Our model provides a tool to estimate the impacts of tilling on soil erosion across the watershed."Lee and co-authors Maria Chu, Jorge Guzman, and Alejandra Botero-Acosta developed the modeling framework, coupling a hydrological model (MIKE SHE) with the Water Erosion Prediction Project (WEPP) to examine the impacts of no-till practice in the watershed. The WEPP model provided the sediment sources from the agricultural fields under different tillage practices and the hydrologic model simulated sediment transport across the watershed.The researchers included historical data on climate, soil properties, sediment sample data, and other relevant measures, then used the coupled model to predict how different management practices affect soil erosion rates."Farmers may prefer tilling because wet climate conditions cause compacted soil," Lee says. "However, soil erosion removes topsoil, which contains lots of nutrients, and this may reduce yield in the long term. Soil erosion also affects water quality, both locally over time and at a distance."Therefore, farmers need to weigh the benefits of tilling with the consequences of soil erosion and choose the best management strategies."The modeling framework can help identify the most vulnerable areas, so producers can implement sustainable management practices where it matters most, Lee notes. | Climate | 2,021 |
January 12, 2021 | https://www.sciencedaily.com/releases/2021/01/210112163630.htm | Wildfire smoke is more cooling on climate than computer models assume | A study of biomass burning aerosols led by University of Wyoming researchers revealed that smoke from wildfires has more of a cooling effect on the atmosphere than computer models assume. | "The study addresses the impact of wildfires on global climate, and we extensively used the NCAR-Wyoming supercomputer (Cheyenne)," says Shane Murphy, a UW associate professor of atmospheric science. "Also, the paper used observations from UW and other teams around the world to compare to the climate model results. The main conclusion of the work is that wildfire smoke is more cooling than current models assume."Murphy was a contributing author of a paper, titled "Biomass Burning Aerosols in Most Climate Models Are Too Absorbing," that was published Jan. 12 (today) in Hunter Brown, who graduated from UW in fall 2020 with a Ph.D. in atmospheric science, was the paper's lead author. Other contributors to the paper included researchers from Texas A&M University; North Carolina A&T State University; the University of Georgia; the Finnish Meteorological Institute; the Center for International Climate and Environmental Science, and Norwegian Meteorological Institute, both in Oslo, Norway; the University of Reading in the United Kingdom; North-West University in South Africa; the University of Science and Technology of China in Hefei, China; and Pacific Northwest National Laboratory in Richland, Wash.The composition, size and mixing state of biomass burning aerosols determine the optical properties of smoke plumes in the atmosphere which, in turn, are a major factor in dictating how these aerosols perturb the energy balance in the atmosphere."We found that many of the most advanced climate models simulate biomass burning aerosols or smoke that is darker, or more light absorbing, than what we see in observations," says Brown, of Juneau, Alaska. "This has implications for the climate predictions made by these models."Observations and models used in the study covered a wide temporal range. Africa, South America and Southeastern Asia, in addition to boreal fire regions, were chosen because these are the largest contributors to biomass burning smoke emissions in the world, Brown says.The National Center for Atmospheric Research (NCAR)-Wyoming Supercomputing Center (NWSC) in Cheyenne was used for all of the data processing and the model sensitivity simulations, Brown says. Some of the other model data used for comparison in this study were generated elsewhere."When we compare global observations of wildfire smoke to simulated wildfire smoke from a collection of climate models, the vast majority of the models have smoke that is more light absorbing than the observations," Brown explains. "This means that more energy from the sun is going toward warming the atmosphere in these models, as opposed to what we see in these field campaigns and laboratory studies, which report less absorbing smoke that has more of a cooling effect by scattering light away from the Earth and back to space."How absorbing these aerosols are in the atmosphere depends on the type of fuel that is burning, as well as the climate of the fire region. Generally, hot, dry grassland fires in Africa and Australia tend to have much darker smoke, which is more absorbing, while cooler, wetter boreal forest fires in North America and Northern Asia tend to have much brighter smoke, which is less absorbing.After researchers made aerosol improvements to the model, African wildfire smoke still tended to be more absorbing than observations. This might be explained by simplifications in how aerosols evolve over time in the model, or it may be due to a lack of observations from this part of the world biasing the results toward the boreal fire regime, Brown explains."We were able to trace the disagreement between the model and observations to how the models represented the individual smoke particles, or aerosols, in the model," Brown says. "This came down to how the model characterized their makeup, their size and the mixtures of different types of biomass burning aerosol. When we changed these variables in one of the models, we saw considerable improvement in the simulated smoke."This comparison of computer models and global observations is valuable for model development groups and may help reduce uncertainty in biomass burning aerosol climate impacts in models, Brown says. | Climate | 2,021 |
January 12, 2021 | https://www.sciencedaily.com/releases/2021/01/210112125215.htm | Soil degradation costs U.S. corn farmers a half-billion dollars every year | One-third of the fertilizer applied to grow corn in the U.S. each year simply compensates for the ongoing loss of soil fertility, leading to more than a half-billion dollars in extra costs to U.S. farmers every year, finds new research from the University of Colorado Boulder published last month in | Long-term soil fertility is on the decline in agricultural lands around the world due to salinization, acidification, erosion and the loss of important nutrients in the soil such as nitrogen and phosphorus. Corn farmers in the U.S. offset these losses with nitrogen and phosphorus fertilizers also intended to boost yields, but scientists have never calculated how much of this fertilizer goes into just regaining baseline soil fertility -- or how much that costs."We know there's land degradation going on even in U.S. modern agriculture, but it's really difficult to pin down how much and what impact it has," said Jason Neff, corresponding author on the paper and director of the Sustainability Innovation Lab at Colorado (SILC). "These findings provide more information to farmers so they can make decisions that benefit them economically, but also support a more sustainable form of high-yield agriculture."The U.S. is one of the most productive countries in the world when it comes to corn, growing more than 4.46 tons per acre farmed. In the 2018-19 growing season alone, U.S. farms produced more than 366 million metric tons of corn which generated $14.5 billion in revenue. The U.S. is also one of the world's largest users of fertilizer, applying more nitrogen and phosphorus per acre than its high-yield agricultural counterparts in the European Union.But using fertilizer doesn't just cost farmers and governments money. It also comes at an environmental cost. A large portion of the global greenhouse gas emissions caused by agriculture -- 24% of global emissions in 2010 and 10% of U.S. emissions in 2018 -- comes from fertilizer production. This means that steps taken to reduce fertilizer use also help address rising greenhouse gases.Excess nitrogen and phosphorus that runs off fields and into rivers and lakes also creates unhealthy conditions for freshwater and marine life, and is responsible for the Dead Zone in the Gulf of Mexico -- a large area depleted of oxygen and devoid of ocean life, including many commercially important species. When we consider not only dollars spent by farmers but also nutrient loss and impacts to the Mississippi River, the costs go from billions to over a trillion dollars every year, said Neff."If you can drop the fertilization, while maintaining the yields that we need and the economic outcomes that farmers want, then why not, right? That's a win-win," said Neff.To separate out this true cost of fertilizer from other modern agricultural inputs, Neff and his colleagues ran a series of scenario-based model analyses using the Environmental Policy Integrated Climate (EPIC) model, a widely used agronomic model used to estimate crop growth and how crop growth responds to variables like fertilizer, irrigation and climate."Doing that lets us then untangle, what's going on with degradation," he said. "What's going on when you change a system from natural to agricultural, and how much of an impact does that have on the nutrients available for plant growth?"The researchers used four scenarios in this model to compare how using no fertilizer or irrigation -- as is in done in many developing economies -- differed from using only one or the other, or both (which is common practice in the U.S.). Irrigation was an important component of the analyses because while it can increase yields, it also increases erosion and fertilizer runoff.By separating the impacts of fertilizer and irrigation, the researchers could see in different regions of the U.S. where each was more important than the other for agricultural success. In California, farmers add more water. In Ohio, fertilizer additions are more important than irrigation. But across the country, they found that it took a whopping one third of fertilizer presently added to cornfields to simply break even, bringing soil fertility back to pre-farmed levels.While this may sound like bad news, Neff sees it as a golden opportunity: with more information, farmers can make better decisions."Farmers do what makes sense to grow crops. When you're not able to see the cumulative effects of degradation, you have to add fertilizers but you're not going to know what the financial impact of that underlying degradation is," said Neff.Practices like regenerative agriculture, which restore soil fertility on lands actively being farmed, will also reduce the costs and environmental impacts of fertilizer use. Healthier, more fertile soils can also capture more carbon, hold more water and keep excess nutrients from running off into ecosystems that can't handle them.Farmers can reduce how often they till their fields, add and increase erosion control measures, as well as use more organic fertilizers, like compost. These can actually help reduce the amount of inorganic fertilizers -- nitrogen and phosphorus -- needed in the soil."My hope is that this information supports national and international efforts to build back soil fertility," said Neff. | Climate | 2,021 |
January 12, 2021 | https://www.sciencedaily.com/releases/2021/01/210112110109.htm | A bucket of water can reveal climate change impacts on marine life in the Arctic | Climate changes prompt many important questions. Not least how it affects animals and plants: Do they adapts, gradually migrate to different areas or become extinct? And what is the role played by human activities? This applies not least to Greenland and the rest of the Artic, which are expected to see the greatest effects of climate changes. | 'We know surprisingly little about marine species and ecosystems in the Arctic, as it is often costly and difficult to do fieldwork and monitor the biodiversity in this area', says Associate Professor of marine mammals and instigator of the study Morten Tange Olsen from the GLOBE Institute at the Faculty of Health and Medical Sciences, University of Copenhagen.To address these questions, researchers from the University of Copenhagen, Aarhus University and the Greenland Institute of Natural Resources collected water samples in West Greenland with the help of local hunters and fishermen. Their method is simple: Go out to sea in a small boat and collect water in bottles. The content, however, is far more complex. The bottles with seawater contain so-called environmental DNA, which can provide insight into how climate changes and human activities impact the biodiversity. The researchers have chosen to focus on the bowhead whale, which constitutes a key species in the Arctic ecosystem and therefore is a good indicator of changes in water temperatures and sea ice cover.'The water samples contain enough DNA from bowhead whales to determine their presence, genetic diversity, the composition of the population and patterns of migration. You can actually monitor the marine biodiversity of the Arctic simply by going out in a small boat and collecting water in bottles, which is subsequently analysed in the DNA laboratory. This way, we are able to keep an eye on how humans and climate changes impact the bowhead whale and other marine life in the Arctic', says Morten Tange Olsen.Together with local hunters and fishermen in Qeqertarsuaq (Godhavn), the researchers collected more than 100 one-litre water samples from Disko Bay in West Greenland in May 2017 and 2018. In May, the sea ice has just broken up and bowhead whales visit the area to forage. The samples were collected from small boats along transects and specifically in the 'footprint' of bowhead whales -- the small ripples on the water surface created when the whales come up to breathe and dive again.'There is a lot more bowhead whale DNA in such a footprint than in a random water sample collected at the same time in the same area. You can find bowhead whale DNA in a footprint at least 10 minutes after the whale dove', says Natasja Lykke Corfixen, who helped initiate the study as part of her master's thesis at the Faculty of Science at the University of Copenhagen and the Greenland Institute of Natural Resources.By optimising the DNA methods in the laboratory, the researchers hope to be able to sequence the whale's entire genome based on water samples. 'So far we have managed to sequence mitochondrial genomes from the water samples, and we are currently testing various methods for capturing the whale's entire genome, as well as the genomes of the algae and crustaceans that form part of their food chain', says PhD Student at the GLOBE Institute Dóra Székely.The researchers hope that by optimising DNA extraction and sequencing protocols, and learning more about the connection between genes, behaviour and health, they will eventually be able to use the method to monitor the health status of the bowhead whale and many other animals.'The field of Environmental DNA is seeing rapid development and is increasingly used for biodiversity monitoring in lakes, rivers, wetlands and, to some extent, the sea. We have shown that the method is also useful in the Arctic, and that it can be used to monitor not just the presence of a species, but also its diversity and patterns of movement. By further developing this simple method we are able to significantly increase our knowledge of marine biodiversity, and hopefully the impact of both climate changes and human activities', says Morten Tange Olsen. | Climate | 2,021 |
January 12, 2021 | https://www.sciencedaily.com/releases/2021/01/210112085411.htm | New study of Earth's crust shows global growth spurt three billion years ago | Curtin University researchers have used ancient crystals from eroded rocks found in stream sediments in Greenland to successfully test the theory that portions of Earth's ancient crust acted as 'seeds' from which later generations of crust grew. | The findings not only advance an understanding of the production of the Earth's crust through deep time, along with its structure and composition, but reveal a planet-wide crustal growth spurt three billion years ago when mantle temperatures peaked.Lead author Professor Chris Kirkland, from Curtin University's Timescales of Mineral Systems Group, said the research used the chemistry of old crystals preserved within stream sediments in arctic Greenland to test the idea that portions of ancient crust served as seeds for later growth of continents."We found there was a widespread bloom in crust production three billion years ago, during a peak in mantle temperatures," Professor Kirkland said."Three-billion-year-old magmas from the mantle had penetrated even more ancient four-billion-year-old crust to create rocks of mixed composition."Old crust appeared to be critical in continent production as it acted much like a life raft to preserve crust through later stages of earth history."The spike in the age of crust production in Greenland matches other regions across the globe and points to a significant widespread event that formed crust relatively early in the history of our planet."Professor Kirkland said understanding the production of crust improved the understanding of its structure and composition."The Earth's crust hosts concentrations of economically valuable ores and minerals but finding them is becoming increasingly challenging as more near-surface deposits are exhausted," Professor Kirkland said."Understanding that later crust is 'seeded' on older pre-existing crust refines our understanding of the generation of where certain metals are hosted and ultimately explains the habitable part of our planet." | Climate | 2,021 |
January 12, 2021 | https://www.sciencedaily.com/releases/2021/01/210112085357.htm | Climate change reduces the abundance and diversity of wild bees | Wild bees are more affected by climate change than by disturbances to their habitats, according to a team of researchers led by Penn State. The findings suggest that addressing land-use issues alone will not be sufficient to protecting these important pollinators. | "Our study found that the most critical factor influencing wild bee abundance and species diversity was the weather, particularly temperature and precipitation," said Christina Grozinger, Distinguished Professor of Entomology and director of the Center for Pollinator Research, Penn State. "In the Northeastern United States, past trends and future predictions show a changing climate with warmer winters, more intense precipitation in winter and spring, and longer growing seasons with higher maximum temperatures. In almost all of our analyses, these conditions were associated with lower abundance of wild bees, suggesting that climate change poses a significant threat to wild bee communities."According to Melanie Kammerer, graduate student in entomology, Penn State, few studies have considered the effects of both climate and land use on wild bees."We thought this was an oversight because, like many organisms, bees are experiencing habitat loss and climate change simultaneously," she said. "By looking at both factors in the same study, we were able to compare the relative importance of these two stressors."To conduct their study, the researchers analyzed a 14-year United States Geological Survey data set of wild bee occurrences from more than 1,000 locations in Maryland, Delaware and Washington, D.C., specifically examining how different bee species and communities respond to land-use and climate factors."To really understand the effects of weather and climate, particularly as weather patterns become more variable with climate change, we need to use these very large, long-term data sets," said Grozinger. "We hope that our study, and others like it, will help encourage the collection and integration of these data sets for future research."Using land cover maps and spatial models, the team described the landscape surrounding each of the sampling locations, including the habitat size and available floral and nesting resources. The team's results appear today (Jan. 12) in "We found that temperature and precipitation patterns are very important drivers of wild bee communities in our study, more important than the amount of suitable habitat or floral and nesting resources in the landscape," said Kammerer.Interestingly, added Grozinger, different bee species were most affected by different weather conditions. For example, she said, areas with more rain had fewer spring bees."We think the rain limits the ability of spring bees to collect food for their offspring," said Grozinger. "Similarly, a very hot summer, which might reduce flowering plants, was associated with fewer summer bees the next year."In addition, warm winters led to reduced numbers of some bee species."This result coincides with studies showing that, with earlier spring onset, overwintering adults had higher pre-emergence weight loss and mortality and shorter life span post-emergence," Grozinger said.Kammerer noted that these weather changes will likely worsen in the coming years."In the future, warm winters and long, hot summers are predicted to occur more frequently, which we expect will be a serious challenge to wild-bee populations," she said. "We are just beginning to understand the many ways that climate influences bees, but in order to conserve these essential pollinators, we need to figure out when, where and how changing climate disrupts bee life cycles, and we need to move from considering single stressors to quantifying multiple, potentially interacting pressures on wild-bee communities."According to the researchers, the study is part of the their larger Beescape project, which allows individuals -- including growers, conservationists and gardeners -- to explore the landscape quality at their site and potentially make adjustments to improve conditions for bees. Given their new findings, the researchers plan to expand Beescape to include weather and climate conditions.Other authors on the paper include Sarah Goslee, ecologist, United States Department of Agriculture Agricultural Research Service; Margaret Douglas, assistant professor of environmental studies, Dickinson College; and John Tooker, professor of entomology, Penn State.The U.S. Department of Agriculture National Institute for Food and Agriculture, the Foundation for Food and Agriculture Research and the College of Agricultural Sciences and Intercollege Graduate Degree Program in Ecology at Penn State supported this research. | Climate | 2,021 |
January 12, 2021 | https://www.sciencedaily.com/releases/2021/01/210112085353.htm | Future too warm for baby sharks | New research has found as climate change causes the world's oceans to warm, baby sharks are born smaller, exhausted, undernourished and into environments that are already difficult for them to survive in. | Lead author of the study Carolyn Wheeler is a PhD candidate at the ARC Centre of Excellence for Coral Reef Studies at James Cook University (Coral CoE at JCU) and the University of Massachusetts. She examined the effects of increased temperatures on the growth, development and physiological performance of epaulette sharks -- an egg-laying species found only on the Great Barrier Reef. She and her team studied the sharks as embryos and as hatchlings."We tested shark embryos in waters up to 31°C," Ms Wheeler said."The hotter the conditions, the faster everything happened, which could be a problem for the sharks. The embryos grew faster and used their yolk sac quicker, which is their only source of food as they develop in the egg case. This led to them hatching earlier than usual."This meant hatchlings were not only smaller, they needed to feed almost straight away -- while lacking significant energy.Co-author Associate Professor Jodie Rummer, also from Coral CoE at JCU, says the waters of the Great Barrier Reef will likely experience summer averages close to or even in excess of 31°C by the end of the century.Since sharks don't care for their eggs after they are laid, a shark egg must be able to survive unprotected for up to four months. Dr Rummer flags rising ocean temperatures as a major concern for the future of all sharks -- both egg-laying and live-bearing species."The epaulette shark is known for its resilience to change, even to ocean acidification," Dr Rummer said. "So, if this species can't cope with warming waters then how will other, less tolerant species fare?" she said.Sharks and the class of animals they belong to, which includes rays and skates, are slow growing. They also don't reproduce that often compared to other fishes. The populations of these creatures are already threatened across the globe.The study suggests the sharks of the future will be born -- or hatch, in this case -- not only at a disadvantage but into environments that are already at the warmest they can tolerate."The study presents a worrying future given that sharks are already threatened," Ms Wheeler said."Sharks are important predators that keep ocean ecosystems healthy. Without predators, whole ecosystems can collapse, which is why we need to keep studying and protecting these creatures.""Our future ecosystems depend us taking urgent action to limit climate change," Dr Rummer said.The research was a collaborative effort between the Anderson Cabot Center for Ocean Life and the husbandry staff at the New England Aquarium in Boston. The New England Aquarium has a successful breeding program for epaulette sharks. | Climate | 2,021 |
January 11, 2021 | https://www.sciencedaily.com/releases/2021/01/210111190141.htm | Climate change has caused billions of dollars in flood damages | In a new study, Stanford researchers report that intensifying precipitation contributed one-third of the financial costs of flooding in the United States over the past three decades, totaling almost $75 billion of the estimated $199 billion in flood damages from 1988 to 2017. | The research, published Jan. 11 in the journal "The fact that extreme precipitation has been increasing and will likely increase in the future is well known, but what effect that has had on financial damages has been uncertain," said lead author Frances Davenport, a PhD student in Earth system science at Stanford's School of Earth, Energy & Environmental Sciences (Stanford Earth). "Our analysis allows us to isolate how much of those changes in precipitation translate to changes in the cost of flooding, both now and in the future."The global insurance company Munich Re calls flooding "the number-one natural peril in the U.S." However, although flooding is one of the most common, widespread and costly natural hazards, whether climate change has contributed to the rising financial costs of flooding -- and if so, how much -- has been a topic of debate, including in the most recent climate change assessments from the U.S. government and the Intergovernmental Panel on Climate Change.At the crux of that debate is the question of whether or not the increasing trend in the cost of flooding in the U.S. has been driven primarily by socioeconomic factors like population growth, housing development and increasing property values. Most previous research has focused either on very detailed case studies (for example, of individual disasters or long-term changes in individual states) or on correlations between precipitation and flood damages for the U.S. overall.In an effort to close this gap, the researchers started with higher resolution climate and socioeconomic data. They then applied advanced methods from economics to quantify the relationship between historical precipitation variations and historical flooding costs, along with methods from statistics and climate science to evaluate the impact of changes in precipitation on total flooding costs. Together, these analyses revealed that climate change has contributed substantially to the growing cost of flooding in the U.S., and that exceeding the levels of global warming agreed upon in the United Nations Paris Agreement is very likely to lead to greater intensification of the kinds of extreme precipitation events that have been most costly and devastating in recent decades."Previous studies have analyzed pieces of this puzzle, but this is the first study to combine rigorous economic analysis of the historical relationships between climate and flooding costs with really careful extreme event analyses in both historical observations and global climate models, across the whole United States," said senior author and climate scientist Noah Diffenbaugh, the Kara J. Foundation Professor at Stanford Earth."By bringing all those pieces together, this framework provides a novel quantification not only of how much historical changes in precipitation have contributed to the costs of flooding, but also how greenhouse gases influence the kinds of precipitation events that cause the most damaging flooding events," Diffenbaugh added.The researchers liken isolating the role of changing precipitation to other questions of cause and effect, such as determining how much an increase in minimum wage will affect local employment, or how many wins an individual player contributes to the overall success of a basketball team. In this case, the research team started by developing an economic model based on observed precipitation and monthly reports of flood damage, controlling for other factors that might affect flooding costs like increases in home values. They then calculated the change in extreme precipitation in each state over the study period. Finally, they used the model to calculate what the economic damages would have been if those changes in extreme precipitation had not occurred."This counterfactual analysis is similar to computing how many games the Los Angeles Lakers would have won, with and without the addition of LeBron James, holding all other players constant," said study co-author and economist Marshall Burke, an associate professor of Earth system science.Applying this framework, the research team found that -- when totaled across all the individual states -- changes in precipitation accounted for 36 percent of the actual flooding costs that occurred in the U.S. from 1988 to 2017. The effect of changing precipitation was primarily driven by increases in extreme precipitation, which have been responsible for the largest share of flooding costs historically."What we find is that, even in states where the long-term mean precipitation hasn't changed, in most cases the wettest events have intensified, increasing the financial damages relative to what would have occurred without the changes in precipitation," said Davenport, who received a Stanford Interdisciplinary Graduate Fellowship in 2020.The researchers emphasize that, by providing a new quantification of the scale of the financial costs of climate change, their findings have implications beyond flooding in the U.S."Accurately and comprehensively tallying the past and future costs of climate change is key to making good policy decisions," said Burke. "This work shows that past climate change has already cost the U.S. economy billions of dollars, just due to flood damages alone."The authors envision their approach being applied to different natural hazards, to climate impacts in different sectors of the economy and to other regions of the globe to help understand the costs and benefits of climate adaptation and mitigation actions."That these results are as robust and definitive as they are really advances our understanding of the role of historical precipitation changes in the financial costs of flooding," Diffenbaugh said. "But, more broadly, the framework that we developed provides an objective basis for estimating what it will cost to adapt to continued climate change and the economic value of avoiding higher levels of global warming in the future." | Climate | 2,021 |
January 11, 2021 | https://www.sciencedaily.com/releases/2021/01/210111125605.htm | Number of people suffering extreme droughts will double | Michigan State University is leading a global research effort to offer the first worldwide view of how climate change could affect water availability and drought severity in the decades to come. | By the late 21st century, global land area and population facing extreme droughts could more than double -- increasing from 3% during 1976-2005 to 7%-8%, according to Yadu Pokhrel, associate professor of civil and environmental engineering in MSU's College of Engineering, and lead author of the research published in "More and more people will suffer from extreme droughts if a medium-to-high level of global warming continues and water management is maintained at its present state," Pokhrel said. "Areas of the Southern Hemisphere, where water scarcity is already a problem, will be disproportionately affected. We predict this increase in water scarcity will affect food security and escalate human migration and conflict."The research team, including MSU postdoctoral researcher Farshid Felfelani, and more than 20 contributing authors from Europe, China and Japan are projecting a large reduction in natural land water storage in two-thirds of the world, also caused by climate change.Land water storage, technically known as terrestrial water storage, or TWS, is the accumulation of water in snow and ice, rivers, lakes and reservoirs, wetlands, soil and groundwater -- all critical components of the world's water and energy supply. TWS modulates the flow of water within the hydrological cycle and determines water availability as well as drought."Our findings are a concern," Pokhrel said. "To date, no study has examined how climate change would impact land water storage globally. Our study presents the first, comprehensive picture of how global warming and socioeconomic changes will affect land water storage and what that will mean for droughts until the end of the century."Felfelani said the study has given the international team an important prediction opportunity."Recent advances in process-based hydrological modeling, combined with future projections from global climate models under wide-ranging scenarios of socioeconomic change, provided a unique foundation for comprehensive analysis of future water availability and droughts," Felfelani said. "We have high confidence in our results because we use dozens of models and they agree on the projected changes."The research is based on a set of 27 global climate-hydrological model simulations spanning 125 years and was conducted under a global modeling project called the Inter-Sectoral Impact Model Intercomparison Project. Pokhrel is a working member of the project."Our findings highlight why we need climate change mitigation to avoid the adverse impacts on global water supplies and increased droughts we know about now," Pokhrel said. "We need to commit to improved water resource management and adaptation to avoid potentially catastrophic socio-economic consequences of water shortages around the world." | Climate | 2,021 |
January 11, 2021 | https://www.sciencedaily.com/releases/2021/01/210111094250.htm | Impacts of climate change on our water and energy systems: it's complicated | As the planet continues to warm, the twin challenges of diminishing water supply and growing energy demand are intensifying. But because water and energy are inextricably linked, as we try to adapt to one challenge -- say, by getting more water via desalination or water recycling -- we may be worsening the other challenge by choosing energy-intensive processes. | So, in adapting to the consequences of climate change, how can we be sure that we aren't making problems worse?Now, researchers at the Department of Energy's Lawrence Berkeley National Laboratory (Berkeley Lab), UC Berkeley, and UC Santa Barbara have developed a science-based analytic framework to evaluate such complex connections between water and energy, and options for adaptations in response to an evolving climate. Their study, "Evaluating cross-sectoral impacts of climate change and adaptations on the energy-water nexus: A framework and California case study," was published recently in the open-access journal "There have been many analyses on how climate change could affect the water and energy sectors separately, but those studies were not typically looking at interactions and feedbacks between the two," said lead author Julia Szinai of Berkeley Lab's Climate and Ecosystem Sciences Division. "Our paper develops a generalized framework that identifies how climate change affects these coupled water and electricity systems, and potential adaptations to future gaps in supply and demand. By doing so, we illustrate often-overlooked tradeoffs and synergies in adapting to climate change.""In developing this project, Julia led a remarkable effort to integrate the climate impacts and feedbacks between the energy and water sectors," said co-author Daniel Kammen, a professor of energy and resources at UC Berkeley. "What is critical to planning our future under climate change is to capture -- in both simplified and full dynamical models ¬- how interdependent are our infrastructure choices."In applying the framework they developed to California, which relies on the snowpack for a good deal of its water and expends significant amounts of energy to transport water from the northern to the southern part of the state, they found that there are two possible adaptation pathways: one that is energy intensive and one that can actually save both water and energy."One of the most important points of the paper is that adapting our water system to climate change can either significantly exacerbate electricity grid stress, or on the flip side, it could help to alleviate it," said co-author and Berkeley Lab climate scientist Andrew Jones. "If we focus on adapting the water system by using big transfers of water across basins, or by using energy-intensive desalination, that's just going to make the electricity problem much more difficult. If, on the other hand, we adapt the water system by conserving water, it's actually a win-win situation because you're also reducing the energy required for water."Currently, a staggering 19% of California's electricity consumption goes toward water-related applications, such as treating it, transporting it, pumping it, and heating it. Additionally, about 15% of in-state electricity generation comes from hydropower. Such interdependencies are referred to as the water-energy nexus. The state has already seen some impacts that climate change could have on these highly interdependent water-energy systems; for example, extended droughts and reduced snowpack have resulted in spikes in electricity consumption from groundwater pumping and hydropower deficits, which were made up by generating electricity using dirtier fossil fuels.Looking ahead, the researchers integrated data across a number of fragmented studies to estimate the overall range of possible water and energy futures under various climate scenarios for the state at the end of the century. Their analysis found that the greatest direct climate change impact on the electricity sector in California will likely come from two factors: higher air conditioning loads and decreased hydropower availability. In the water sector, the greatest and most uncertain impact of climate change is on future water supplies. In the worst case, available water supplies could decrease 25%, and in the best case could increase 46%.Applying their framework to California's water-energy future, they found that, if the state were to adapt to the worst-case water scenario by choosing the most energy-intensive technologies, it could result in an energy imbalance as large as that caused by climate change itself (increased air conditioning use and decreased hydropower availability being the climate change factors having the greatest direct energy imbalance impact)."I think this is the first study to show that water sector adaptation can have as large of an impact on the electricity sector as the direct effect of climate change itself," said Jones. "So, if we pursued the energy-intensive path to water sector adaptation then it is as large as the direct effect of climate change, in the worst case."Co-author Ranjit Deshmukh, a professor of environmental studies at UC Santa Barbara and faculty scientist at Berkeley Lab, noted, "Going forward, the electricity sector could leverage its close coupling with the water sector to enable balancing of increasing wind and solar generation in California as the state strives to meet its low-carbon-emission goals. For example, energy-intensive equipment such as water pumps or desalination plants, with adequate water storage, could be operated during times of plentiful solar and wind energy, and turned off at other times."Next, Szinai, a UC Berkeley graduate student, said she plans to develop detailed models of both water and electricity systems so researchers can run simulations under various climate change and climate change adaptation scenarios, ultimately aiding planners in building out both the electrical grid and water resources."This study has highlighted the benefit of coordinated adaptation planning between the two sectors, so we're now linking a more detailed water resources management model and an electricity planning model that can demonstrate resilient pathways for building out electricity infrastructure in the Western U.S. when climate change impacts are included from the water sector," she said. | Climate | 2,021 |
January 11, 2021 | https://www.sciencedaily.com/releases/2021/01/210111084220.htm | Understanding origins of Arizona's Sunset Crater eruption of 1,000 years ago | Around 1085 AD, along the southern rim of Northern Arizona's elevated Colorado Plateau, a volcano erupted, forever changing ancient Puebloan fortunes and all nearby life. Among the 600 or so volcanoes that dot the landscape of the San Francisco volcanic fields, this one blew. It was the very first (and last) eruption for what came to be known as Sunset Crater, aptly named for its multi-hued, 1,000-foot-tall cinder cone. | Today, ASU School of Earth and Space Exploration scientist Amanda Clarke and her team have been working to solve the mysterious root cause of the Sunset Crater eruption and any lessons learned to better understand the threats similar volcanoes may pose around the world today."This is a common thing in volcanology, to reconstruct past eruptions to try to understand what the volcano or region might do in the future," said Clarke. "We did the field work and we combined data from a previous study and used some modern techniques to put the story together."Working alongside several collaborators, they have painstakingly mapped every fissure, eruption deposit, and ancient lava flow of Sunset Crater to reconstruct the complete splatter patterns and geochemical compositions of all ejected materials, or tephra, from the eruption."When you visit the site, there are these lava flows that are obvious, but also this big tephra blanket that extends far beyond the volcanic edifice itself, way beyond the vent," said Clarke. "My interest was first piqued when I learned on a field trip many years ago with former ASU professor Stephen Self, that Sunset Crater had an explosive past."In a previous study, Clarke's group first showed that the volcanic activity developed in seven or eight distinct phases: initial fissure phases, followed by highly explosive phases, and finally, low-explosivity, waning phases. "It's not clear how this happens, but eventually, the eruption settled on this single pipeline to the surface, and that's where a lot of our work picks up the story," said Clarke.At several points during the explosive phase, the sky was filled with basaltic, cindery ash up to 20 to 30km high, making it one of the most explosive volcanic eruptions of its kind ever documented in the world."People in Winslow [100km away] would have been able to see it," said Clarke. To give one an idea of the eruption size, they measured the total volume of eruption material, or 0.52 km3 dense rock equivalent (DRE) -- -which, by comparison, turned out to be similar to the volume of the infamous 1980 Mount St. Helens eruption. "It was very similar to Mt. St. Helens in terms of height and volume," said Clarke. "You think these things that are cinder cones are going to be something like Stromboli in Italy -- -a fire fountain of a couple of hundred meters and people might be able to watch it from their terrace -- -but this peak phase was St. Helens scale."But as to why it erupted, that has remained a mystery, until now. "The science question is how these more liquidy magmas behave like viscous magmas," said Clarke. The study, published in the journal Measuring the factors that led to the Sunset Crater eruption 1,000 years later is an extremely difficult task because the gases that make up the magma usually escape into the sky during the eruption, forever lost in time. But to better reconstruct the past, the group have taken advantage of extensive microanalyses from the tiniest blobs and bubbles that are the best representation of the composition of magma from Sunset Crater before the eruption, known as melt inclusions. Roggensack is recognized as a world expert in innovative melt inclusion analysis, especially in basaltic magmas.How tiny? Melt inclusions are less than a thousandth of an inch across. They become embedded in time within growing crystals of the magma plumbing system that forms before a volcano erupts. "They've been liberated from the magma in the explosion," said Clarke.They are like a fizzy, soda concoction of trapped gas, frozen in time from the surrounding magma as they crystalize, yet able to reveal the gas composition and secret history of an eruption so long ago.Think of the basaltic Sunset Crater having more of a maple syrup consistency versus the peanut butter variety of the rhyolite magma of Mt. St. Helens. "Those are viscous magmas that can have a lot of water stuffed in them," said Clarke."That leads to the big questions of what is the volatile content of the magma because that is going to control the explosivity," said Clarke. "To answer the questions, you have to dig down deep into the plumbing system, and that's what we did."Clarke's group is among the first to show the importance of carbon dioxide in volcanic eruptions, partly because it wasn't easy task to measure in the first place. "We think this eruption could have pumped a fair amount of carbon dioxide and also sulfur dioxide into the atmosphere," said Clarke."Water is usually the main component [as in Mt. St. Helens] but what we are finding at Sunset is that carbon dioxide is very abundant and that tends to be more critical in the deeper part of the system to get the magma moving toward the surface. We think that played a big role in this. And the carbon dioxide is probably coming from deep in the mantle within the source area."The melt inclusions (MIs) were specifically chosen to provide a representative sample of textural features observed in the Sunset Crater eruption (e.g., varying bubble volumes, sizes and shapes). Some of the tools of the trade used were microscopes to bring the details of crystallization and bubble formation for each tiny melt inclusion to life, as well as sensitive instruments to measure the amount of volatiles trapped in the quenched glass."That can tell us some of the details of the last moments of the magma before it was quenched."Using a custom-built Raman spectrometer at ASU in the LeRoy Eyring Center for Solid State Science (LE-CSSS), Chelsea Allison set up the melt inclusion analysis in which samples are first excited using a blue sapphire laser. High-quality melt inclusions were polished and imaged with a petrographic microscope in preparation for Raman analysis.Like a Russian doll, nestled inside the little crystal is this little melt inclusion (now glass), and then inside the melt inclusion is a bubble, and inside the bubble is carbon dioxide."Raman spectroscopy can be used to measure the density of carbon dioxide, and then from the volume and density of the bubble, you can use that to calculate a mass," said Clarke. "Allison had to do all kinds of stuff including creating standards to ensure what she was measuring was accurate. She used known amounts of carbon dioxide inside little glass tubes to make a calibration curve.""People used to ignore the bubbles, thinking there was nothing important inside, but it turns out it was almost all carbon dioxide," said Clarke. "We've added that carbon dioxide inside the bubble to the total carbon dioxide budget of the magma.""That all ties together, because once you have the volumes of the eruption, and the total volatile content of the magma, you can start understanding how much got ejected into the atmosphere, and what does that look like compared to other eruptions."The carbon dioxide gas phase played a critical role in driving the explosive eruption, with the gas stored in the magma of Sunset Crater as deep as 15km below the surface."We think that magma was bubbling already at 15km deep, and that's not what people typically think about magma systems with these volcanoes. It has been demonstrated before that you have a bubble phase. And if you have a system that is already bubbly and that deep, it means you might have a really rapid ascent."Although, the impact of basaltic volcanism on the global atmospheric system is largely unknown, this high carbon dioxide and sulfur from the eruption could have also had a large impact on the atmosphere at the time of the eruption.They also compared the magmatic volatiles at Sunset Crater to those in explosive caldera-forming silicic eruptions such as the Bishop Tuff to highlight differences in their abundance and composition. This comparison suggested that the carbon dioxide rich phase is a critical pre-eruptive condition that drives highly explosive basaltic eruptions.Explosive silicic eruptions, although still much larger in terms of erupted volume, are better analogies to the dynamics of the Sunset Crater eruption. Two such historical eruptions, the 1991 eruption at Pinatubo (Philippines) and the 1815 eruption of trachyandesite at Tambora (Indonesia), resulted in profound atmospheric impacts.The Pinatubo eruption, which had significant impact on global climate for three years post-eruption, erupted 10 times the mass of magma (5 km3 DRE) as Sunset Crater (0.5 km3 DRE), but released just ~3 times the mass of sulfur dioxide. The Tambora eruption was responsible for the "year without a summer," and while it erupted ~60 times the mass of magma (30 km3 DRE) as Sunset Crater, it released only ~9 times the mass of sulfur dioxide.The lessons learned from Sunset Crater and its type of basaltic volcanism could still inform us today."Now we can ask, are the conditions that led to the Sunset Crater eruption really that unusual?" said Clarke. "How common is it for us to see a basaltic cinder cone that we think should be a gentle, observable eruption turn into something that is much more hazardous to aircraft flying overhead or to the people around it? We can start to apply these concepts to active systems.""And remember, though the vent at Sunset Crater is not going to erupt again, the San Francisco field is still active. There will probably be another eruption there. It could be anywhere, and probably in the eastern sector, but we don't know where and when. It could be on a scale of thousands of years." | Climate | 2,021 |
January 10, 2021 | https://www.sciencedaily.com/releases/2021/01/210110192431.htm | Positive 'tipping points' offer hope for climate | Positive "tipping points" could spark cascading changes that accelerate action on climate change, experts say. | A tipping point is a moment when a small change triggers a large, often irreversible, response.Professor Tim Lenton, Director of the Global Systems Institute (GSI) at the University of Exeter, has previously warned the world is "dangerously close" to several tipping points that could accelerate climate change.But in a new paper in the journal They highlight examples of such tipping points that have contributed to the world's fastest low-carbon transitions in road transport and power generation -- and say "small coalitions of countries" could trigger "upward-scaling tipping cascades" to achieve more."We have left it too late to tackle climate change incrementally," said Professor Lenton."Limiting global warming to well below 2°C now requires transformational change, and a dramatic acceleration of progress."For example, the power sector needs to decarbonise four times faster than its current rate, and the pace of the transition to zero-emission vehicles needs to double."Many people are questioning whether this is achievable. But hope lies in the way that tipping points can spark rapid change through complex systems."The authors highlight two examples where policy interventions have already triggered pertinent tipping points at a national scale.For each, they explain how further actions could turn these into "cascades" that change the global economy:These positive tipping cascades are by no means inevitable -- policies will be required to overcome the many barriers to transition.But the beauty of tipping points is that thanks to reinforcing feedbacks, a relatively small number of initial actions could catalyse large changes at the global scale.The paper encourages potential partners to work together to make these tipping cascades a reality."If either of these efforts -- in power or road transport -- succeed, the most important effect could be to tip perceptions of the potential for international cooperation to tackle climate change," Professor Lenton said.The paper is entitled: "Upward-scaling tipping cascades to meet climate goals: plausible grounds for hope." | Climate | 2,021 |
January 8, 2021 | https://www.sciencedaily.com/releases/2021/01/210108111048.htm | Scientists develop a cheaper method that might help create fuels from plants | Scientists have figured out a cheaper, more efficient way to conduct a chemical reaction at the heart of many biological processes, which may lead to better ways to create biofuels from plants. | Scientists around the world have been trying for years to create biofuels and other bioproducts more cheaply; this study, published today in the journal "The process of converting sugar to alcohol has to be very efficient if you want to have the end product be competitive with fossil fuels," said Venkat Gopalan, a senior author on the paper and professor of chemistry and biochemistry at The Ohio State University. "The process of how to do that is well-established, but the cost makes it not competitive, even with significant government subsidies. This new development is likely to help lower the cost."At the heart of their discovery: A less expensive and simpler method to create the "helper molecules" that allow carbon in cells to be turned into energy. Those helper molecules (which chemists call cofactors) are nicotinamide adenine dinucleotide (NADH) and its derivative (NADPH). These cofactors in their reduced forms have long been known to be a key part of turning sugar from plants into butanol or ethanol for fuels. Both cofactors also play an important role in slowing the metabolism of cancer cells and have been a target of treatment for some cancers.But NADH and NADPH are expensive."If you can cut the production cost in half, that would make biofuels a very attractive additive to make flex fuels with gasoline," said Vish Subramaniam, a senior author on the paper and recently retired professor of engineering at Ohio State. "Butanol is often not used as an additive because it's not cheap. But if you could make it cheaply, suddenly the calculus would change. You could cut the cost of butanol in half, because the cost is tied up in the use of this cofactor."To create these reduced cofactors in the lab, the researchers built an electrode by layering nickel and copper, two inexpensive elements. That electrode allowed them to recreate NADH and NADPH from their corresponding oxidized forms. In the lab, the researchers were able to use NADPH as a cofactor in producing an alcohol from another molecule, a test they did intentionally to show that ¬the electrode they built could help convert biomass -- plant cells -- to biofuels. This work was performed by Jonathan Kadowaki and Travis Jones, two mechanical and aerospace engineering graduate students in the Subramaniam lab, and Anindita Sengupta, a postdoctoral researcher in the Gopalan lab.But because NADH and NADPH are at the heart of so many energy conversion processes inside cells, this discovery could aid other synthetic applications.Subramaniam's previous work showed that electromagnetic fields can slow the spread of some breast cancers. He retired from Ohio State on Dec. 31.This finding is connected, he said: It might be possible for scientists to more easily and affordably control the flow of electrons in some cancer cells, potentially slowing their growth and ability to metastasize.Subramaniam also has spent much of his later scientific career exploring if scientists could create a synthetic plant, something that would use the energy of the sun to convert carbon dioxide into oxygen. On a large enough scale, he thought, such a creation could potentially reduce the amount of carbon dioxide in the atmosphere and help address climate change."I've always been interested in that question of, 'Can we make a synthetic plant? Can we make something that can solve this global warming problem with carbon dioxide?'" Subramaniam said. "If it's impractical to do it with plants because we keep destroying them via deforestation, are there other inorganic ways of doing this?"This discovery could be a step toward that goal: Plants use NADPH to turn carbon dioxide into sugars, which eventually become oxygen through photosynthesis. Making NADPH more accessible and more affordable could make it possible to produce an artificial photosynthesis reaction.But its most likely and most immediate application is for biofuels.That the researchers came together for this scientific inquiry was rare: Biochemists and engineers don't often conduct joint laboratory research.Gopalan and Subramaniam met at a brainstorming session hosted by Ohio State's Center for Applied Plant Sciences (CAPS), where they were told to think about "big sky ideas" that might help solve some of society's biggest problems. Subramaniam told Gopalan about his work with electrodes and cells, "and the next thing we knew, we were discussing this project," Gopalan said. "We certainly would not have talked to each other if it were not for the CAPS workshop." | Climate | 2,021 |
January 8, 2021 | https://www.sciencedaily.com/releases/2021/01/210108084110.htm | New analysis highlights importance of groundwater discharge into oceans | An invisible flow of groundwater seeps into the ocean along coastlines all over the world. Scientists have tended to disregard its contributions to ocean chemistry, focusing on the far greater volumes of water and dissolved material entering the sea from rivers and streams, but a new study finds groundwater discharge plays a more significant role than had been thought. | The new findings, published January 8 in "It's really hard to characterize groundwater discharge, so it has been a source of uncertainty in the modeling of global cycles," said first author Kimberley Mayfield, who led the study as a graduate student at UC Santa Cruz. "It took a large effort by researchers around the world who came together to make this happen."The researchers focused on five key elements -- lithium, magnesium, calcium, strontium, and barium -- measuring concentrations and isotope ratios in coastal groundwater at 20 sites around the world, and using previously published data from additional sites."Those elements are important because they come from the weathering of rocks, and weathering of silicate rocks accounts for a huge uptake of carbon dioxide from the atmosphere over long time scales," Mayfield explained.Coauthor Adina Paytan, a research professor in UCSC's Institute of Marine Sciences, said groundwater is an important source of inputs to the oceans, but has been easy to ignore because it is unseen and hard to measure."This is the first global assessment of groundwater discharge for most of these elements," Paytan said. "This information is useful for our understanding of how weathering of rock is related to climate, not only in the present but also in the past."The study estimated that the amount of these elements entering the sea from groundwater is at least 5%, and up to 16%, of the contributions from rivers based on the latest global groundwater flux estimates. The results also showed that the isotopic composition of groundwater discharge can be different from that of rivers."The composition of groundwater discharge is very dependent on coastal geology, whereas river water is more influenced by the interiors of continents," Mayfield said. "It's important to recognize that groundwater makes a difference globally, and now that we have this large data set, people can keep improving it with more sampling and develop better models of global groundwater discharge." | Climate | 2,021 |
January 7, 2021 | https://www.sciencedaily.com/releases/2021/01/210107135710.htm | Research confirms increase in river flooding and droughts in US, Canada | The number of "extreme streamflow" events observed in river systems have increased significantly across the United States and Canada over the last century, according to a study from Dartmouth College. | In regions where water runoff from snowmelt is a main contributor to river streamflow, the study found a rise in extreme events, such as flooding.In drought-prone regions in the western and southeastern U.S., the study found that the frequency of extreme low-flow events has also become more common, particularly during summer and fall.The research, published in "Floods and droughts are extremely expensive and often life-threatening events," said Evan Dethier, a postdoctoral researcher at Dartmouth and the lead author of the paper. "It's really important that we have good estimates of how likely extreme events are to occur and whether that likelihood is changing."Although changes in precipitation and extreme streamflows have been observed in the past, there has been no research consensus on whether droughts and floods have actually increased in frequency.Past research efforts have mostly focused on annual peak flows, potentially missing important seasonal changes to extreme low-flow events that can be pulled from daily streamflow records. Those efforts have also been hampered by the mixing of data from regions that have different precipitation patterns and natural seasonal cycles.According to the research paper: the results demonstrate that "increases in the frequency of both high- and low-flow extreme streamflow events are, in fact, widespread.""Previous attempts to analyze regional pattern in streamflow were usually based on fixed geographical regions that were largely unsuccessful," said Carl Renshaw, a professor of earth sciences at Dartmouth. "The novel clustering approach used in this research defines regions based on the hydrology -- not geographical or political boundaries -- to better reveal the significant shifts occurring for both high and low streamflows."The Dartmouth study combined 541 rivers in the U.S. and Canada into 15 hydrological regions organized by seasonal streamflow characteristics, such as whether streams flood due to tropical storms or rain falling on melting snow. This grouping allowed for more sensitive detection of trends in extreme flow events on both an annual and seasonal basis.Out of the 15 "hydro-regions" created, 12 had enough rivers to be analyzed in the study. The rivers studied were judged to be minimally affected by human activity and included extensive records that span 60 or more years."The shifts toward more extreme events are especially important given the age of our dams, bridges, and roads. The changes to river flows that we found are important for those who manage or depend on this type of infrastructure," said Dethier.According to the study, in the regions where streamflow changes were found to be statistically significant, floods and droughts have, on average, doubled in frequency relative to the period of 1950 to 1969.Significant changes in the frequency of floods were found to be most common in the Canadian and northern U.S. regions where annual peak flows are consistently associated with spring snowmelt runoff.The increase in flooding has come despite reduction in snowpack caused by warming winter temperatures. The research team believes that the increases in extreme precipitation during the high-flow season may make up for the reduction in snowpack storage.Changes in drought and extreme low-flow frequency were found to be more variable.While floods were found to be more localized, droughts were found to be "generally reflective of large-scale climatic forcing" and more likely to be widespread across a region. | Climate | 2,021 |
January 7, 2021 | https://www.sciencedaily.com/releases/2021/01/210107125239.htm | Power, water and climate | As the planet continues to warm, the twin challenges of diminishing water supply and growing energy demand will intensify. But water and energy are inextricably linked. For instance, nearly a fifth of California's energy goes toward water-related activities, while more than a tenth of the state's electricity comes from hydropower. As society tries to adapt to one challenge, it needs to ensure it doesn't worsen the other. | To this end, researchers from UC Santa Barbara, Lawrence Berkeley National Laboratory and UC Berkeley have developed a framework to evaluate how different climate adaptations may impact this water-energy nexus. Their research appears in the open access journal "Electricity and water systems are linked in many different ways," said coauthor Ranjit Deshmukh, an assistant professor in the environmental studies department. "Climate change is expected to stress these links so we presented a framework that maps these interdependencies and will enable us to understand and quantify its impacts on the energy-water nexus."Although it's not the first study to look at these topics, it takes a more nuanced approach than the papers that have come before. "There have been many analyses on how climate change could affect the water and energy sectors separately, but those studies were not typically looking at interactions and feedbacks between the two," said lead author Julia Szinai of Berkeley Lab's Climate and Ecosystem Sciences Division. "Our paper develops a generalized framework that identifies how climate change affects these coupled water and electricity systems and potential adaptations to future gaps in supply and demand. By doing so we illustrate often overlooked tradeoffs and synergies in adapting to climate change."The framework uses systems analysis to identify the biggest potential climate stressors on the water and energy sectors. It quantifies actions that will be needed to adapt to climate change, and examines the feedbacks that would result from these actions."For example, our framework shows how increased temperatures due to climate change will likely increase electricity demand for air conditioning and water demand for irrigation," Deshmukh explained. "Whereas snowpack loss in the Sierras and variable precipitation will affect the water supply, not just for urban and agricultural use, but also for hydropower generation and thermal power plant cooling."California relies on snowpack in the Sierra Nevadas to slowly mete out water over the course of the year.The team applied the framework they developed to California, which relies on the snowpack for a good deal of its water and expends significant amounts of energy to transport water from the north to the southern part of the state. They examined multiple adaptation strategies in the water sector and found that some are energy intensive while others can actually save both water and energy.The researchers integrated data across a number of fragmented studies to estimate the overall range of possible water and energy futures for the state under various climate scenarios at the end of the century. Their analysis found that two factors will likely dominate climate change's direct impacts on California's electricity sector: higher air conditioning loads and decreased hydropower availability."One of the most important points of the paper is that adapting our water system to climate change can either significantly exacerbate electricity grid stress, or on the flip side, it could help to alleviate it," said co-author and Berkeley Lab climate scientist Andrew Jones. "If we focus on adapting the water system by using big transfers of water across basins, or by using energy-intensive desalination, that's just going to make the electricity problem much more difficult. If, on the other hand, we adapt the water system by conserving water, it's actually a win-win situation because you're also reducing the energy required for water."Currently, a staggering 19% of California's electricity consumption goes toward water-related applications, such as treating, transporting, pumping and heating. Additionally, about 15% of in-state electricity generation comes from hydropower.The state has already seen some impacts of climate change on its water-energy systems. Extended droughts exacerbated by climate change have led to spikes in electricity consumption for groundwater pumping, and corresponding hydropower deficits have required replacement by dirtier fossil fuels.The team is certain that the climate crisis will have a huge impact on the state's future water supplies. That said, the effect is wildly uncertain. In the worst case, available water supplies could decrease 25%; however, they could increase 46%."There are significant uncertainties in the climate model projections for precipitation," said Deshmukh. "But irrespective of those uncertainties, the adaptation measures offer significant co-benefits." Conserving water would save energy as well as money for consumers, and allow for greater flow in the state's natural streams and rivers.When the team applied their framework to the worst-case scenario, they found that choosing the most energy-intensive adaptation strategies in the water sector could result in an energy imbalance as large as that caused directly by climate change."I think this is the first study to show that water sector adaptation can have as large of an impact on the electricity sector as the direct effect of climate change itself," said Jones."This study has highlighted the benefit of coordinated adaptation planning between the two sectors," added lead author Szinai, "so we're now linking a more detailed water resources management model and an electricity planning model that can demonstrate resilient pathways for building out electricity infrastructure in the Western U.S. when climate change impacts are included from the water sector."Deshmukh is currently leading a team to explore the connections between energy, water and the climate by quantifying the impacts of climate change on hydropower dams and thermal power plants in 12 countries across southern Africa. He hopes to identify optimal investments in electricity infrastructure."California has a choice in how it wants to adapt its water sector to the impacts of climate change," Deshmukh stated. "The state can either pursue energy intensive climate adaptation measures such as desalination or develop a portfolio of measures that maximize water conservation potential. Planners and policymakers in the water and energy sectors need to coordinate their actions and plans for adapting to climate change."The study was supported by the Department of Energy Office of Science and the National Science Foundation. It is part of DOE's HyperFACETS project. | Climate | 2,021 |
January 7, 2021 | https://www.sciencedaily.com/releases/2021/01/210107112405.htm | Rising lizard temperatures may change predator-prey relationship with snakes | In a study spanning four decades, researchers from the University of Hong Kong's Research Division for Ecology & Biodiversity (HKU) in the Faculty of Science, and Toho University's Department of Biology (Toho), Japan, have discovered that predation by snakes is pushing lizards to be active at warmer body temperatures on islands where snakes are present, in comparison to islands free from snakes. Their work also detected significant climatic warming throughout the years and found lizard body temperatures to have also increased accordingly. The findings show that lizard thermal biology is highly dependent on predation pressures and that body temperatures are rising suggest that such ectothermic predator-prey relationships may be changing under climatic warming. | The research published in the journal In this system, one dominant lizard species is found on all these islands; Okada's five-lined skink (Plestiodon latiscutatus). Its mainland predator, the Japanese four-lined rat snake (Elaphe quadrivirgata), is found on most but not all of the islands. This has resulted P. latiscutatus populations that have experienced different evolutionary pressures, either free from or subject to predation by E. quadrivirgata.The research was conducted by PhD student Félix LANDRY YUAN (HKU) and PhD Candidate Shun ITO (Tohoku University's Graduate School of Life Science) and led by Dr Timothy BONEBRAKE (HKU) and Professor Masami HASEGAWA (Toho). Initial observation and data collection was first started by Professor HASEGAWA in the early 1980's, when he first noticed lizard behaviour differed on islands with and without snakes. Professor Hasegawa has since continually visited the islands annually to catch lizards and snakes for body temperature and morphological measurements. The researchers have accordingly detected that annual temperatures across the Izu Islands had increased by just over 1°C since Professor Hasegawa first started his observations, and that lizard body temperature had also increased with the same magnitude.In addition to body temperature measurements, in 2018 and 2019 Félix Landry Yuan carried a portable racetrack, tripod and camera to the islands to measure the speed at which lizards ran at different temperatures. By analyzing thermally dependent running speeds of over 150 lizards across the islands, the researchers were able to establish how predation by snakes affected lizard thermal biology and the probable consequences for their fitness. Dr Bonebrake notes that: "by racing lizards of different temperatures down a track, Félix was able to show that optimal temperatures were higher for lizards on the island with snakes, consistent with the high body temperatures observed on the island. Shun Ito was also able to identify differences in lizard hind leg length that had consequences for survival. Thus, the higher body temperatures and morphological differences help the lizards run faster and better escape the snakes. The exciting and unique aspect of this work is how the experimental work matches and supports the extensive natural history data and observation."With climate change ongoing, the dynamics of this prey-predator relationship could be affected on islands with snakes, as lizard body temperatures are likely to continue to rise. In addition, as predation has considerable consequences for the thermal biology of its prey, the presence or absence of snake predators could differentially influence general vulnerability of lizards to climatic warming across islands.The Izu Islands demonstrate the value of island systems in teasing apart mechanisms through which predation directly influences behaviour, morphology and physiology of prey species. On the other hand, understanding the ways in which predation can affect prey responses to climate change requires long-term study. This international collaboration between HKU and Toho used these unique properties of this system (and Professor Hasegawa's forethought and intensive data collections since the 80s) to show how predator-prey relationships may be vulnerable in a warming climate. "It is a great pleasure to reveal ecological and evolutionary responses among prey and predator interactions by this international research team. I'm very hopeful that the Izu islands become a key model island system to study ongoing evolution under global environmental change by attracting ambitious young Asian biologists to research this further." Professor HASEGAWA said. | Climate | 2,021 |
January 7, 2021 | https://www.sciencedaily.com/releases/2021/01/210107112400.htm | Native biodiversity collapse in the Eastern Mediterranean | The coastline of Israel is one of the warmest areas in the Mediterranean Sea. Here, most marine species have been at the limits of their tolerance to high temperatures for a long time -- and now they are already beyond those limits. Global warming has led to an increase in sea temperatures beyond those temperatures that Mediterranean species can sustain. Consequently, many of them are going locally extinct. | Paolo Albano's team quantified this local extinction for marine molluscs, an invertebrate group encompassing snails, clams and mussels. They thoroughly surveyed the Israeli coastline and reconstructed the historical species diversity using the accumulations of empty shells on the sea bottom.The shallow habitats at scuba diving depths are affected most. Here, the researchers were not able to find living individuals of up to 95 per cent of the species whose shells were found in the sediments. The study suggests that most of this loss has occurred recently, presumably in just the last few decades.Additionally, most of the species still found alive cannot grow enough to reproduce, "a clear sign that the biodiversity collapse will further continue," says Albano. In contrast, the tropical species that enter from the Suez Canal thrive. The warm waters in the Eastern Mediterranean are very suitable habitats for them. Indeed, they occur in large populations and their individuals are fully fit to reproduce."For anyone accustomed to snorkel or dive in the Mediterranean," explains the researcher, "the underwater scenario in Israel is unrecognisable: The most common species are missing, while in contrast tropical species are everywhere."The future perspectives for the Mediterranean are not good. The sea will continue to warm even if we would stop carbon dioxide emissions today. This is due to the inertia of the system, the long braking distance, so to speak.It is thus likely that the biodiversity collapse will continue to spread. It may already be occurring in other eastern Mediterranean areas not surveyed yet, and it will expand to the West and intensify. Only intertidal organisms, which are to some extent pre-adapted to temperature extremes, and habitats in deeper water, where the temperature is markedly lower, will continue to persist -- at least for some time."But the future is dim unless we immediately act to reduce our carbon emissions and to protect marine habitats from other pressures which contribute to biodiversity loss," says Paolo Albano, "The changes that already occurred in the warmest areas of the Mediterranean may not be reversible, but we would be able to save large parts of the rest of the basin."Methodologically, the study was also interesting due to its interdisciplinary character: "These results came from the cooperation of scientists with very different backgrounds," says Martin Zuschin, Head of the Department of Palaeontology and co-author of the study -- "In particular, the cooperation between ecologists and palaeontologists is providing unique new views on how humankind is impacting biodiversity." | Climate | 2,021 |
January 7, 2021 | https://www.sciencedaily.com/releases/2021/01/210107112416.htm | Hawai'i drought during El Niño winter? Not always, according to new research | El Niño events have long been perceived as a driver for low rainfall in the winter and spring in Hawai'i, creating a six-month wet-season drought. However, a recent study by researchers in the University of Hawai'i at Manoa School of Ocean and Earth Science and Technology (SOEST) revealed the connection between Hawai'i winter rainfall and El Niño is not as straightforward as previously thought. | Studies in the past decade suggested that there are at least two types of El Niño: the Eastern Pacific and Central Pacific, when the warmest pool of water is located in the eastern or central portions of the ocean basin, respectively. El Niño events usually begin in summer and last for about one year.The UH M?noa team of atmospheric scientists analyzed data on the large-scale circulation patterns over the eastern and central Pacific to find that Hawai'i drought is only associated with the Eastern Pacific El Niño. For the central Pacific El Niño events, deficient rainfall in Hawaii occurred only 60% of the time. Therefore, a winter drought is not guaranteed following a Central Pacific El Niño.The differences in how the Eastern and Central Pacific El Niño affect rainfall can be critical for proper planning and water resource management."This new result is a boon for many agencies in Hawai'i, for example, the Board of Water Supply, Hawai'i Department of Land and Natural Resources, and Hawai'i Department of Agriculture," said Pao-Shin Chu, SOEST professor, Hawai'i State Climatologist and co-author of the study. "Beyond these agencies, ranchers, flower growers, and other stakeholders that are concerned with the relationship between El Niño and water supply in Hawai'i may also benefit from the new findings."Given that El Niño is a recurring phenomenon, knowing the type of El Niño that occurs will allow researchers and resource managers to more easily evaluate and prepare for Hawaiian regional climate in winter.The team continues their research to explore other large-scale climate factors dominating the Hawaiian regional climate and affecting trade winds and rainfall patterns.This study was also co-authored by SOEST atmospheric scientists Bo-Yi Lu, doctoral candidate and lead author; postdoctoral researcher Sung-Hun Kim; and associate professor Christina Karamperidou. | Climate | 2,021 |
January 6, 2021 | https://www.sciencedaily.com/releases/2021/01/210106142656.htm | Modern microbes provide window into ancient ocean | Step into your new, microscopic time machine. Scientists at the University of Colorado Boulder have discovered that a type of single-celled organism living in modern-day oceans may have a lot in common with life forms that existed billions of years ago -- and that fundamentally transformed the planet. | The new research, which will appear Jan. 6 in the journal These single-celled, photosynthetic organisms, also known as "blue-green algae," can be found in almost any large body of water today. But more than 2 billion years ago, they took on an extra important role in the history of life on Earth: During a period known as the "Great Oxygenation Event," ancient cyanobacteria produced a sudden, and dramatic, surge in oxygen gas."We see this total shift in the chemistry of the oceans and the atmosphere, which changed the evolution of life, as well," said study lead author Sarah Hurley, a postdoctoral research associate in the departments of Geological Sciences and Biochemistry. "Today, all higher animals need oxygen to survive."To date, scientists still don't know what these foundational microbes might have looked like, where they lived or what triggered their transformation of the globe.But Hurley and her colleagues think they might have gotten closer to an answer by drawing on studies of naturally-occurring and genetically-engineered cyanobacteria. The team reports that these ancient microbes may have floated freely in an open ocean and resembled a modern form of life called beta-cyanobacteria.Studying them, the researchers said, offers a window into a time when single-celled organisms ruled the Earth."This research gave us the unique opportunity to form and test hypotheses of what the ancient Earth might have looked like, and what these ancient organisms could have been," said co-author Jeffrey Cameron, an assistant professor of biochemistry.You can still make the case that cyanobacteria rule the planet. Hurley noted that these organisms currently produce about a quarter of the oxygen that comes from the world's oceans.One secret to their success may lie in carboxysomes -- or tiny, protein-lined compartments that float inside all living cyanobacteria. These pockets are critical to the lives of these organisms, allowing them to concentrate molecules of carbon dioxide within their cells."Being able to concentrate carbon allows cyanobacteria to live at what are, in the context of Earth's history, really low carbon dioxide concentrations," Hurley said.Before the Great Oxidation Event, it was a different story. Carbon dioxide levels in the atmosphere may have been as much as 100 times what they are today, and oxygen was almost nonexistent. For that reason, many scientists long assumed that ancient microorganisms didn't need carboxysomes for concentrating carbon dioxide."Cyanobacteria have persisted in some form over two billion years of Earth's history," she said. "They could have been really different than today's cyanobacteria."To find out how similar they were, the researchers cultured jars filled with bright-green cyanobacteria under conditions resembling those on Earth 2 billion years ago.Hurley explained that different types of cyanobacteria prefer to digest different forms, or "isotopes," of carbon atoms. As a result, when they grow, die and decompose, the organisms leave behind varying chemical signatures in ancient sedimentary rocks."We think that cyanobacteria were around billions of years ago," she said. "Now, we can get at what they were doing and where they were living at that time because we have a record of their metabolism."In particular, the team studied two different types of cyanobacteria. They included beta-cyanobacteria, which are common in the oceans today. But the researchers also added a new twist to the study. They attempted to bring an ancient cyanobacterium back from the dead. Hurley and her colleagues used genetic engineering to design a special type of microorganism that didn't have any carboxysomes. Think of it like a zombie cyanobacterium."We had the ability to do what was essentially a physiological resurrection in the lab," said Boswell Wing, a study coauthor and associate professor of geological sciences.But when the researchers studied the metabolism of their cultures, they found something surprising: Their zombie cyanobacterium didn't seem to produce a chemical signature that aligned with the carbon isotope signatures that scientists had previously seen in the rock record. In fact, the best fit for those ancient signals were likely beta-cyanobacteria -- still very much alive today.The team, in other words, appears to have stumbled on a living fossil that was hiding in plain sight. And, they said, it's clear that cyanobacteria living around the time of the Great Oxygenation Event did have a structure akin to a carboxysome. This structure may have helped cells to protect themselves from growing concentrations of oxygen in the air."That modern organisms could resemble these ancient cyanobacteria -- that was really counterintuitive," Wing said.Scientists, they note, now have a much better idea of what ancient cyanobacteria looked like and where they lived. And that means that they can begin running experiments to dig deeper into what life was like in the 2 billion-year-old ocean."Here is hard evidence from the geological record and a model organism that can shed new light on life on ancient Earth," Cameron said.Other coauthors on the new paper included CU Boulder undergraduate student Claire Jasper and graduate student Nicholas Hill. | Climate | 2,021 |
January 6, 2021 | https://www.sciencedaily.com/releases/2021/01/210106112006.htm | Will global warming bring a change in the winds? Dust from the deep sea provides a clue | The westerlies -- or westerly winds -- play an important role in weather and climate both locally and on a global scale, by influencing precipitation patterns, impacting ocean circulation and steering tropical cyclones. So, finding a way to assess how they will change as the climate warms is crucial. | Typically, the westerlies blow from west to east across the planet's middle latitudes. But scientists have noticed that over the last several decades, these winds are changing, migrating poleward. Research suggests this is because of climate change. But, scientists have been debating whether the poleward movement of the westerlies will continue as temperatures and atmospheric carbon dioxide (COIn a paper published January 6 in The finding represents a breakthrough in our understanding of how the winds changed in the past, and how they may continue to change in the future.By using dust in ancient, deep sea sediments as an indirect tracer of wind, the researchers were able to reconstruct wind patterns that occurred three to five million years ago. Knowing that winds -- in this case the westerlies -- transport dust from desert regions to faraway locations, the authors examined cores from the North Pacific Ocean. This area is downwind from Eastern Asia, one of the largest dust sources today and a known dust-generating region for the past several million years. By measuring the dust in cores from two different sites thousands of kilometers apart, the researchers were able to map changes in dust, and in turn the westerly winds."We could immediately see the patterns. The data are so clear. Our work is consistent with modern observations, and suggests that wind patterns will change with climate warming," said Abell.They found that during the warm parts of the Pliocene (a period three to five million years ago, when the Earth was about two to four degrees Celsius warmer than today but had approximately the same concentration of CO"By using the Pliocene as an analogue for modern global warming, it seems likely that the movement of the westerlies towards the poles observed in the modern era will continue with further human-induced warming," explained Winckler.The movement of these winds have huge implications for storm systems and precipitation patterns. And while this research does not indicate exactly where it will rain more or less, it confirms that the wind and precipitation patterns will change with climate warming."In the Earth history record, tracking down movements of wind and how they've changed, that's been elusive because we didn't have a tracer for it," said Winckler. "Now we do."Robert Anderson from Columbia University's Lamont-Doherty Earth Observatory and Brown University's Timothy Herbert were co-authors on this study. | Climate | 2,021 |
January 6, 2021 | https://www.sciencedaily.com/releases/2021/01/210106095312.htm | The new face of the Antarctic | In the future, the Antarctic could become a greener place and be colonised by new species. At the same time, some species will likely disappear. 25 researchers recently presented these and many other findings in a major international project, in which they analysed hundreds of articles on the Antarctic published in the past ten years. By doing so, the team have provided an exceptionally comprehensive assessment of the status quo and future of Antarctica and the Southern Ocean that surrounds it. | Never before have researchers arrived at so many new findings on the biological and biochemical processes at work in the Antarctic than in the past ten years. Now 25 experts, led by the Alfred Wegener Institute Helmholtz Centre for Polar and Marine Research (AWI), have analysed and compiled these findings in the project "AnT-ERA." Having ultimately processed several hundred articles on the Antarctic, the team have now distilled the content into ten core messages addressing a broad range of aspects, e. g. ocean acidification, biodiversity, and the significance of sea ice for various organisms. "If you look at the timeframe from 1970 to the present, roughly 80 percent of all academic publications on biology and biochemistry in the Antarctic were released between 2010 and 2020. That's what moved us to condense this enormous amount of knowledge into a single article," says marine biologist and project coordinator Julian Gutt from the AWI. The project outcomes have just been published in the journal One major finding is that the waters of the Antarctic are very likely to grow warmer due to climate change, which in turn increases the probability that plant and animal species from warmer regions will migrate to the Antarctic. In this regard, not just the temperature, but also the future sea-ice cover will be crucial. For example, in the decades to come, the experts expect to see a more intense greening of ice-free coastal areas during the southern summer, as new mosses or lichens migrate. Initially, there will likely be a rise in biodiversity. However, a prolonged warming would have grave consequences for those species that are adapted to extremely low temperatures. "We believe these species will retreat to the last remaining extremely cold regions of the Antarctic," says Gutt. "That also means we'll need to protect the regions in order to save these species."When it comes to ocean acidification, the study's forecast is bleak: by the end of the century, the experts expect the waters of the Antarctic to be extensively acidified. "There can be no doubt that especially those organisms that form calcareous shells are going to have serious problems," Gutt explains. "We can't yet say for certain if they will all go extinct, or if some species will manage to adapt their metabolisms to the new conditions." A surprising finding from research conducted in the past ten years: the ostensibly docile organisms that live on the floor of the Antarctic Ocean, e.g. some sponges and ascidians, respond rapidly to improved conditions -- by growing quickly or reproducing intensively. The downside: they are equally sensitive to poor environmental conditions. Given the major changes that climate change will entail, these species could also be in danger.Whereas the Antarctic Peninsula, which extends into the South Atlantic, has been warming for some time now, in the past three years the warming, and therefore the loss of sea ice, has spread to East Antarctica. The experts can't yet say whether this is the beginning of a long-term trend, or only a short-term variation. In either case, this change in the physical environmental parameters is troubling, because it could have a substantial impact on the future development of life in the Southern Ocean.It also remains unclear whether or not the loss of sea ice will mean that the waters of the Antarctic, due to intensified algal growth, absorb more carbon dioxide from the atmosphere. Principally speaking, most experts assume that algal growth increases when sea ice retreats, because the algae e. g. are exposed to more sunlight. Since algae absorb carbon dioxide from the atmosphere via photosynthesis when they grow, this process can improve the ocean's absorption of COThe experts chiefly attribute the fact that so many new insights have been gathered in recent years to technological advances -- e. g. in molecular biological methods, new ships and stations, and remotely operated underwater vehicles, some of which can even navigate below the ice. In addition, new numerical and conceptual models are helping us to understand interconnections in the ecosystem. In Julian Gutt's view, the study's greatest contribution is the fact that the 25 authors successfully agreed upon ten core messages that succinctly convey the central findings and offer a glimpse of the future. | Climate | 2,021 |
January 5, 2021 | https://www.sciencedaily.com/releases/2021/01/210105160816.htm | Dungeness crab fishing industry response to climate shock | Fishermen contend with regulations, natural disasters, and the ups and downs of the stocks they fish, along with many other changes. As a result, fishing communities are quite resilient. That is, they can withstand, recover from, and adapt to change. | But how much pressure can they stand? The 2014-2016 North Pacific marine heatwave, known as the Blob, led to a harmful algal bloom of unprecedented scale. It necessitated substantial delays in the opening of the 2015-16 U.S. West Coast Dungeness crab fishery. The fishery is vital to West Coast communities. It produces around 26 percent of all annual fishing revenue and supports more than 30 percent of all commercial fishing vessels.Previous studies have documented the devastating economic impacts from the 2015-16 event on Dungeness crab fishermen. Members of affected coastal communities attest that these socioeconomic effects rippled through associated industries and coastal communities. But can changes in fishing practices in response to this significant climate shock be quantified?"We wanted to examine the extent to which the Dungeness crab fishery delays affected participation in other fisheries, and the duration of those changes," said Mary Fisher, a doctoral student at the University of Washington. Fisher did the work as a National Science Foundation Graduate Research Internship Program Fellow at NOAA's Northwest Fisheries Science Center.Fisher and her colleagues at NOAA Fisheries, University of Washington, and Oregon State University studied the impacts on more than 2,500 vessels across seven California fishing communities. The researchers wanted to see how a climate-related shock (like the heatwave and associated harmful algal bloom) can impact communities' use of ocean resources.The researchers used 10 years of fishery landings data to map resource use networks for seven California port groups where Dungeness crab is an important revenue source. The networks visualize the portfolio of fisheries that a community harvests and how vessels move between fisheries. The network visualization is similar to a food web, except that the connections represent harvest by fishing vessels rather than predator-prey relationships.Researchers found that 71 percent of California Dungeness crab fishing vessels temporarily left the industry and stopped fishing altogether during the delays. The two other strategies that fishermen used to cope with the disruption were:These strategies significantly changed communities' resource use patterns, but some communities were more affected by the climate shock than others. Researchers could predict which communities would be least sensitive to the shock by looking at their resource use patterns before the 2015-16 season.These communities, located in central California, were less dependent on Dungeness crab and had shorter fishery delays. In these communities, fishermen had access to more open fisheries during the winter months and were more flexible in how they fished previously. These characteristics provided more options, buffering fishermen from the disruption to the Dungeness crab fishing season.No matter how central Dungeness crab was to a community's fisheries portfolio, the researchers didn't observe any significant, lasting changes in how vessels participated in fisheries after the closures lifted. This suggests fishing communities may mostly return to "normal" fishing practices relatively quickly after short-term disturbances like climate shocks, provided those changes don't pile up one after the other.The results highlight the importance of nearshore groundfish fisheries like sablefish, rockfish, and lingcod as alternatives to the Dungeness crab fishery. "Most of the crab vessels that stayed out on the water were using pot or hook-and-line gear to fish groundfish," says Fisher. "I think we can expect access to these fisheries to continue to be important during crab season delays."Fishermen with larger vessels also landed their catch at different ports, a strategy less common among smaller vessels. This was possible in part because regulations only restricted fishing in delayed areas at the district level. In 2018, the California Department of Fish and Wildlife amended these rules, called the Fair Start Provisions. The amendments provide more protection to fishermen at a finer scale than districts in the event of future delays. | Climate | 2,021 |
January 5, 2021 | https://www.sciencedaily.com/releases/2021/01/210105135702.htm | Identifying Canada's key conservation hot spots highlights problem | To stop biodiversity loss, Canada recently committed to protecting 30% of its land and sea by 2030. But making conservation decisions about where to locate new protected areas is complicated. It depends on data both about biodiversity and about a range of benefits (e.g. freshwater, climate regulation, recreation) that people get from nature. Surprisingly, despite the size of the country, new mapping suggests that less than 1% of Canada's land (0.6% of total area or approximately 56,000 km2) is a hot spot, providing all these benefits in one place. Moreover, the study published today in | "This research is especially timely as it should help all levels of government design conservation plans that ensure that both people and nature thrive," says Elena Bennett, from McGill University's Bieler School of the Environment and one of the authors in a multi-institutional team that included researchers from Universities of British Columbia, McGill and Carleton and from the Yellowstone to Yukon Conservation Initiative (Y2Y).The paper highlights multiple places across Canada as important for one or more ecosystem services that include providing freshwater (such as for irrigation, drinking or hydroelectricity), climate regulation (as in the case of forests and wetlands that act as carbon sinks), or for nature-based human recreation. These include the forests of British Columbia and the Hudson Bay lowlands for above- and below-ground carbon; north-central Quebec, the eastern mountains of British Columbia, the eastern slopes of the Rockies in Alberta, and the north shore of Lake Superior for freshwater; and the Rocky Mountains, eastern Ontario, and southern Quebec for nature-based recreation."Canada is grappling with where and how to protect nature. Just one example of how this research could be used is in western Alberta. Our research shows that the Eastern Slopes of the Rockies is one of the most important places across the whole country for its combination of freshwater, carbon storage, and recreation -- not to mention important wildlife habitat -- and yet the same area is at risk from open-pit coal mining and other threats," says Dr. Aerin Jacob, co-author and conservation scientist, at the Yellowstone to Yukon Conservation Initiative.Crucially and unusually, the mapping methods included both nature's capacity to supply these benefits as well as the human access and demand for them."Most research that studies the benefits people get from nature only evaluates where nature has the potential to supply these benefits. For example, where rain falls. Because our work also models and maps human access and demand, we could identify where people actually receive these benefits from nature. For example, the key locations producing water that people use for drinking, farming, or hydroelectricity," says Dr. Matthew Mitchell, lead author and Research Associate, Institute for Resources, Environment, and Sustainability, University of British Columbia. "Governments need to know both of these things in order to take action that protects human well-being. Research like this can help society do that." | Climate | 2,021 |
January 5, 2021 | https://www.sciencedaily.com/releases/2021/01/210105130131.htm | Climate change caused mangrove collapse in Oman | Most of the mangrove forests on the coasts of Oman disappeared about 6,000 years ago. Until now, the reason for this was not entirely clear. A current study of the University of Bonn (Germany) now sheds light on this: It indicates that the collapse of coastal ecosystems was caused by climatic changes. In contrast, falling sea level or overuse by humans are not likely to be the reasons. The speed of the mangrove extinction was dramatic: Many of the stocks were irreversibly lost within a few decades. The results are published in the journal | Mangroves are trees that occupy a very special ecological niche: They grow in the so-called tidal range, meaning coastal areas that are under water at high tide and dry at low tide. Mangroves like a warm climate; most species do not tolerate sea surface temperatures below 24 °C (75°F). They are tolerant to salt, but only up to a tolerance limit that varies from species to species. "This is why we find them nowadays mostly in regions where enough rain falls to reduce salinization of the soil," explains Valeska Decker of the Institute for Geosciences at the University of Bonn, the lead author of the study.Fossil finds prove that there used to be many mangrove lagoons on the coast of Oman. However, some 6,000 years ago these suddenly largely vanished - the reasons for this were previously disputed. Over the past few years, Decker traveled several times to the easternmost country of the Arabian Peninsula to pursue this question for her doctoral thesis. With the support of her doctoral supervisor Prof. Gösta Hoffmann, she compiled numerous geochemical, sedimentological and archaeological findings into an overall picture. "From our point of view, everything suggests that the collapse of these ecosystems has climatic reasons," she says.Along the equator there is a low pressure trough, the Intertropical Convergence Zone, which is situated a little further north or south depending on the season. The Indian summer monsoon, for example, is linked to this zone. It is believed that about 10,000 years ago this zone was much further north than today, which meant the monsoon affected large parts of the Arabian Peninsula. Just over 6,000 years ago this low-pressure trough then shifted to the south, but the reason for this and how fast is still not completely clear."That this was the case has been well documented for several years," explains Decker. "Our results now indicate that this climate change had two effects: On the one hand, it caused salinization of the soil, which put the mangroves under extreme stress. On the other hand, the vegetation cover in the affected areas decreased in general due to the greater drought." This increased erosion: The wind carried large amounts of the barren soil into the lagoons. These silted up and successively dried up. The whole thing happened surprisingly fast: "The ecosystems probably disappeared within a few decades," stresses Decker. According to previous studies, the environmental changes were gradual. The mangrove ecosystems struggled till a certain threshold was reached and then collapsed within decades. Nowadays, the only mangroves in Oman are those of a particularly robust species and are found only in a few places.She was able to exclude other possible causes for the disappearance of the mangroves in her study. For example, the researchers found no evidence of a drop in sea level 6,000 years ago that could have triggered the mangrove extinction. "Archaeological findings also speak against a man-made ecological catastrophe," she says. "It is true that there were humans living in the coastal regions who used the mangroves as firewood. However, they were nomads who did not build permanent settlements. This meant that their need for wood was relatively low - low enough to rule out overuse as a cause."Decker and her colleagues now want to further investigate how much the annual precipitation changed and what impact this had on the region. To this end, the researchers plan to study the pollen that has persisted in the lagoon sediment for thousands of years. They want to find out how the vegetation changed as a result of the drought. The results could also be relevant for us: In many regions of the world, the climate is changing at a dramatic pace. Germany has also suffered increasingly from long droughts in recent years. Foresters are therefore already planning to plant more drought-resistant species in this country; this is a consequence of climate change that may leave long-term marks in the history of vegetation. | Climate | 2,021 |
January 5, 2021 | https://www.sciencedaily.com/releases/2021/01/210105130123.htm | Leaf fossils show severe end-Cretaceous plant extinction in southern Argentina | The asteroid impact 66 million years ago that ushered in a mass extinction and ended the dinosaurs also killed off many of the plants that they relied on for food. Fossil leaf assemblages from Patagonia, Argentina, suggest that vegetation in South America suffered great losses but rebounded quickly, according to an international team of researchers. | "Every mass extinction event is like a reset button, and what happens after that reset depends on which organisms survive and how they shape the biosphere," said Elena Stiles, a doctoral student at the University of Washington who completed the research as part of her master's thesis at Penn State. "All the biodiversity that we observe today is related to the organisms that made it past the last big reset 66 million years ago."Stiles and her colleagues examined more than 3,500 leaf fossils collected at two sites in Patagonia to identify how many species from the geologic period known as the Cretaceous survived the mass extinction event into the Paleogene period. Although plant families in the region fared well, the scientists found a surprising species-level extinction rate that may have reached as high as 92% in Patagonia, higher than previous studies have estimated for the region."There's this idea that the Southern Hemisphere got off easier from the Cretaceous-Paleogene extinction than the Northern Hemisphere because we keep finding plant and animal groups that no one thought survived," said Peter Wilf, professor of geosciences at Penn State and associate in the Earth and Environmental Systems Institute. "We went into this study expecting that Patagonia was a refuge, and instead we found a complex story of extinction and rebound."Researchers from Penn State; the Museo Paleontologico Egidio Feruglio (MEF), Chubut, Argentina; Universidad Nacional del Comahue INIBIOMA, Rio Negro, Argentina; and Cornell University had been collecting the fossils for years from the two sites, in what is now Chubut province. Unlike North America, where the Cretaceous-Paleogene (K-Pg) boundary is well known from many sites in the western United States, the fossil record from this period is fragmented across the Southern Hemisphere, a result of rapidly changing ancient environments."Most of the Cretaceous-Paleogene boundary interval known from the Southern Hemisphere is marine," said Ari Iglesias, a researcher at Universidad Nacional del Comahue INIBIOMA. "We were interested in obtaining the continental record, what happened on land. So, in this study we tried to get as close to the K-Pg boundary as possible, and we reached it in a small area in Chubut province. There we found floras right before the K-Pg boundary, or Maastrichtian floras, and right after the K-Pg boundary, so Danian age floras."The assemblages that the team obtained constitute the most complete collection of late Cretaceous and early Paleogene fossil floras in the Southern Hemisphere, added Iglesias.The researchers studied the assemblages for survivor pairs -- plants that grew in both the Cretaceous and Paleogene periods -- and found few species-level matches. They then compared their findings to previous pollen and insect herbivory studies from the same area and to North American fossil records. Their study, which is the first of its kind in the Southern Hemisphere, appears in the journal Paleobiology."The 92% extinction estimate we get when we consider fossil leaf species across the K-Pg boundary should be taken as a maximum" Stiles said. "We were surprised to find such high extinction levels compared with the 60% extinction rate seen in North America. Nonetheless, we observed a sharp drop in plant species diversity and a high species-level extinction."Ecosystem recovery likely took millions of years, added Stiles, which is a small fraction of Earth's nearly 4.5-billion-year history.Stiles also led a novel morphospace analysis to identify changes in leaf shape from the Cretaceous to the Paleogene, as such changes could provide clues to the kinds of environmental and climatic occurrences that took place across the boundary interval. She studied each leaf fossil for nearly 50 features, including shape, size and venation patterns.The analysis showed a higher diversity of leaf forms in the Paleogene, which surprised the researchers given the high species-level extinction and drop in number of species at the end of the Cretaceous. They also found an increase in the proportion of leaf shapes typically found in cooler environments, which suggests that climatic cooling occurred after the end-Cretaceous extinction event.The researchers' findings, combined with those of previous studies, suggest that despite the high species-level extinction at the end of the Cretaceous, South American plant families largely survived and grew more diverse during the Paleogene. Among the survivors were the laurel family, which today includes plants such as bay leaves and avocados, and the rose family, which includes fruit like raspberries and strawberries."Plants are often overlooked in these big events in geologic history," Stiles said. "But really, because plants are the primary producers on terrestrial landscapes and sustain all other life forms on Earth, we should be paying closer attention to the plant fossil record. It can tell us how the landscape changed and how those changes affected different groups of organisms."The Geological Society of America, Mid-American Paleontological Society, National Science Foundation and Penn State, through a Charles E. Knopf, Sr. Memorial Scholarship and the Paul D. Krynine Memorial Fund, supported this research. | Climate | 2,021 |
January 5, 2021 | https://www.sciencedaily.com/releases/2021/01/210105130112.htm | Drought of the century in the Middle Ages -- with parallels to climate change today? | The transition from the Medieval Warm Period to the Little Ice Age was apparently accompanied by severe droughts between 1302 and 1307 in Europe; this preceded the wet and cold phase of the 1310s and the resulting great famine of 1315-21. In the journal | The Great Famine (1315-1321) is considered the largest pan-European famine of the past millennium. It was followed a few years later by the Black Death (1346-1353), the most devastating pandemic known, which wiped out about a third of the population. At least partially responsible for both of these crises was a phase of rapid climate change after 1310, called the "Dantean Anomaly" after the contemporary Italian poet and philosopher Dante Alighieri. The 1310s represent a transitional phase from the High Medieval Climate Anomaly, a period of relatively high temperatures, to the Little Ice Age, a long climatic period characterized by lower temperatures and advancing glaciers.The Leipzig-based researchers are studying the regions of northern Italy, southeastern France, and east central Europe. These areas have been little studied with regard to the Great Famine thus far, but offer a variety of historical sources for the reconstruction of extreme meteorological events and their socio-economic effects, including how vulnerable societies were at the time. "We want to show that historical climate change can be reconstructed much better if written historical sources are incorporated alongside climate archives like tree rings or sediment cores. The inclusion of humanities research clearly contributes to a better understanding of the social consequences of climate change in the past and to drawing conclusions for the future," explains Dr Martin Bauch from the GWZO, who heads the junior research group.The study now published evaluates a large number of historical sources: chronicles from present-day France, Italy, Germany, Poland, and the Czech Republic. Regional and municipal chronicles provided information on historical city fires, which were an important indicator of droughts. Administrative records from Siena (Italy), the County of Savoy (France) and the associated region of Bresse shed light on economic developments there. Using the data, it was possible, for example, to estimate wheat and wine production in the French region of Bresse and compare it with wheat production in England. Since these yields depend strongly on climatic factors such as temperature and precipitation, it is thus possible to draw conclusions about the climate in the respective production years.While the summer of 1302 was still very rainy in central Europe, several hot, very dry summers followed from 1304 onwards. From the perspective of climate history, this was the most severe drought of the 13th and 14th centuries. "Sources from the Middle East also report severe droughts. Water levels in the Nile, for example, were exceptionally low. We therefore think that the 1304-06 drought was not only a regional phenomenon, but probably had transcontinental dimensions," reports Dr. Thomas Labbé from the GWZO.Based on the recorded effects, the team reconstructed the historical weather conditions between the summer of 1302 and 1307. Through evaluations of the 2018 drought and similar extreme events, it is now known that, in such cases, a so-called "precipitation seesaw" usually prevails. This is the meteorological term for a sharp contrast between extremely high precipitation in one part of Europe and extremely low precipitation in another. "This is usually caused by stable high and low pressure areas that remain in one region for an unusually long time. In 2018, for example, very stable lows lay over the North Atlantic and southern Europe for a long time, which led to heavy precipitation there and an extreme drought in between in central Europe," explains meteorologist Dr Patric Seifert from TROPOS, who was responsible for reconstructing the large-scale weather situations for the study. The analysis of the possible large-scale weather situations indicates that between 1303 and 1307, a strong, stable high pressure system predominated over central Europe, which explains the extreme drought in these years.The analysis of these historical weather situations is particularly interesting given the ongoing discussion about how climate change in the Arctic affects weather patterns in Europe. In recent decades, the Arctic has warmed more than twice as much as other regions of the world. This phenomenon, called "Arctic Amplification," is being studied by a DFG Collaborative Research Centre led by the University of Leipzig. One theory assumes that the disproportionate warming of the Arctic causes the temperature differences -- and thus also the atmospheric dynamics -- between the mid-latitudes and the region around the North Pole to decrease. As a result, according to a common hypothesis, weather patterns may persist longer than in the past. "Even if it was a phase of cooling in the Middle Ages and we are now living in a phase of man-made warming, there could be parallels. The transitional period between two climate phases could be characterized by smaller temperature differences between the latitudes and cause longer-lasting large-scale weather patterns, which could explain an increase in extreme events," Seifert cautions.In their study, the researchers recorded a noticeable coincidence between the periods of drought and urban fires. Fires were a great danger for the densely constructed cities in the Middle Ages, where there were no fire brigades like there are today. The best documented fire between 1302 and 1307 was probably in Florence, where over 1,700 houses burned on 10 June 1304. Sources for Italy and France showed a correlation between extreme drought and fires. "We think our analysis is the first to find a correlation between fires and droughts over a two-hundred-year period. Large urban fires usually followed droughts by a year. The wooden structures in medieval houses did not dry out immediately. But once they did, they ignited very easily," explains Bauch. Contemporaries were also aware of the connection between drought and fire: during dry periods, citizens were obliged to place buckets of water next to their front doors -- a primitive sort of fire extinguisher, to be kept available at all times. It was only later that municipalities organized fire brigades, for example in Florence around 1348. Major infrastructural measures in response to the droughts have survived in the cities of northern Italy: Parma and Siena invested in larger, deeper wells, and Siena also bought a harbor on the Mediterranean coast, which it expanded after the drought years of 1302-04 in order to be able to import grain and become less dependent on domestic production."According to our analysis, the drought of 1302-1307 was a once-in-a-century event with regard to its duration. No other drought reached these dimensions in the 13th and 14th centuries. The next event that came close was not until the drought of 1360-62, which stretched across Europe and for which there indications in the historical record in Japan, Korea, and India," concludes Annabell Engel, M.A., from GWZO. In connection with global warming, researchers expect more frequent extreme events such as droughts. While numerous studies have already documented strong fluctuations in the 1340s, shortly before the plague epidemic, the first decade of the 14th century, unlike the 1310s, has been the focus of little research so far. The Leibniz researchers have now been able to show for the first time that exceptionally dry summers between 1302 and 1304 to the south of the Alps and 1304 and 1307 north of the Alps were the result of stable weather conditions and disparately distributed precipitation. The study thus sheds new light on the first years of the 14th century with its dramatic changes and draws a link to modern climate changes. "However, it is difficult to draw conclusions about future climatic developments in the 21st century from our study. While climate fluctuations in the 14th century were natural phenomena, in the modern age, humans are exerting artificial influence on the climate, as well," note Bauch and Seifert. | Climate | 2,021 |
January 5, 2021 | https://www.sciencedaily.com/releases/2021/01/210105111837.htm | Imminent sudden stratospheric warming to occur, bringing increased risk of snow over coming weeks | A new study led by researchers at the Universities of Bristol, Exeter, and Bath helps to shed light on the winter weather we may soon have in store following a dramatic meteorological event currently unfolding high above the North Pole. | Weather forecasting models are predicting with increasing confidence that a sudden stratospheric warming (SSW) event will take place today, 5 January 2021.The stratosphere is the layer of the atmosphere from around 10-50km above the earth's surface. SSW events are some of the most extreme of atmospheric phenomena and can see polar stratospheric temperature increase by up to 50°C over the course of a few days. Such events can bring very cold weather, which often result in snowstorms.The infamous 2018 "Beast from the East" is a stark reminder of what an SSW can bring. The disturbance in the stratosphere can be transmitted downward and if this continues to the earth's surface, there can be a shift in the jet stream, leading to unusually cold weather across Europe and Northern Asia. It can take a number of weeks for the signal to reach the surface, or the process may only take a few days.The study, published in the Findings in the paper, Tracking the stratosphere-to-surface impact of Sudden Stratospheric Warmings suggest split events tend to be associated with colder weather over north west Europe and Siberia.Lead author of the study, Dr Richard Hall, said there was an increased chance of extreme cold, and potentially snow, over the next week or two:"While an extreme cold weather event is not a certainty, around two thirds of SSWs have a significant impact on surface weather. What's more, today's SSW is potentially the most dangerous kind, where the polar vortex splits into two smaller "child" vortices.""The extreme cold weather that these polar vortex breakdowns bring is a stark reminder of how suddenly our weather can flip. Even with climate change warming our planet, these events will still occur, meaning we must be adaptable to an ever more extreme range of temperatures," said Dann Mitchell, Associate Professor of Atmospheric Science at the University of Bristol and co-author of the study."Our study quantifies for the first time the probabilities of when we might expect extreme surface weather following a sudden stratospheric warming (SSW) event. These vary widely, but importantly the impacts appear faster and stronger following events in which the stratospheric polar vortex splits in two, as is predicted in the currently unfolding event. Despite this advance many questions remain as to the mechanisms causing these dramatic events, and how they can influence the surface, and so this is an exciting and important area for future research," said Dr William Seviour, senior lecturer at the Department of Mathematics and Global Systems Institute, University of Exeter, and co-author of the study. | Climate | 2,021 |
January 5, 2021 | https://www.sciencedaily.com/releases/2021/01/210105095630.htm | Rare footage captured of jaguar killing ocelot at waterhole | In what may be a sign of climate-change-induced conflict, researchers have captured rare photographic evidence of a jaguar killing another predatory wild cat at an isolated waterhole in Guatemala. | In the footage, a male jaguar arrives near the waterhole and apparently lies in wait for an hour. It lets a potentially dangerous prey animal, a large tapir, pass by, but when the ocelot stops to drink, the jaguar pounces and carries off the smaller predator.The event, detailed in a recent study published in the journal "Although these predator-on-predator interactions may be rare, there may be certain instances when they become more prevalent, and one of those could be over contested water resources," said Daniel Thornton, a WSU assistant professor and co-author on the paper. "People don't often think of tropical systems as being dry, but in many parts of the world, tropical rains are quite seasonal, and with climate change, some of these tropical ecosystems are expected to become even more seasonal. The more isolated and rare water resources become, the more they're going to become hotspots of activity."Jaguars which can weigh more than 200 pounds typically prey on small animals like armadillos or peccaries. Ocelots, also carnivores, are smaller than their larger jaguar cousins at around 18 to 44 pounds, and their activity patterns overlap with the jaguars particularly in twilight periods of the day.While some research has noted signs of ocelot in jaguar feces, until now, no known images have been captured of a jaguar directly killing an ocelot."These dramatic camera trap images clearly show the fierce competition wildlife face for precious resources like water," said Rony García-Anleu of WCS's Guatemala Program and a co-author of the study. "Unfortunately, climate change and associated droughts are predicted to worsen, which means tough times are ahead for wildlife that depend on watering holes for their survival."The researchers had placed cameras at 42 waterholes in the area in 2018 and 2019. In the 2019 dry season only 21 had water, and none of those were within 10 km (6.2 miles) of this particular waterhole. At this same remote spot, scientists also recorded a fight between two jaguars and a jaguar attempting to attack a young tapir. They also noted that seven different jaguars frequented this waterhole, which is unusual for a species that normally avoids its peers and sticks to its own territory.The jaguar-ocelot kill was captured as part of a larger monitoring project looking at the distribution of animals across the entire landscape in northern Guatemala, especially in relation to human pressures. Ironically, this waterhole was one that was far from any human community, but that did not mean it was necessarily unaffected by human activity."We have evidence that many things are happening related to climate change, but we might not be aware of every detail, of every consequence," said Lucy Perera-Romero, a WSU doctoral student and lead author on the study. "For example, in these beautiful, green forests, we may not be aware that water flow is a serious issue. It could be another source of mortality -- apart from deforestation, from hunting, and from everything else that we do."The Maya Forest is one of Mesoamerica's 5 Great Forests, spanning from Mexico to Colombia, collectively covering an area three times the size of Switzerland. The 5 Great Forests are all transboundary and represent Mesoamerica's most critical bastions for jaguars and other wildlife, and provide services such as carbon sequestration, clean water and food security to five million people. | Climate | 2,021 |
January 5, 2021 | https://www.sciencedaily.com/releases/2021/01/210105084656.htm | Uncovering how grasslands changed our climate | Grasslands are managed worldwide to support livestock production, while remaining natural or semi-natural ones provide critical services that contribute to the wellbeing of both people and the planet. Human activities are however causing grasslands to become a source of greenhouse gas emissions rather than a carbon sink. A new study uncovered how grasslands used by humans have changed our climate over the last centuries. | Grasslands are the most extensive terrestrial biome on Earth and are critically important for animal forage, biodiversity, and ecosystem services. They absorb and release carbon dioxide (COTo address this knowledge gap, an international research team quantified the changes in carbon storage and greenhouse gas fluxes in natural and managed grasslands between 1750 and 2012 in their study published in "We built and applied a new spatially explicit global grassland model that includes mechanisms of soil organic matter and plant productivity changes driven by historical shifts in livestock and the reduction of wild grazers in each region. This model is one of the first to simulate the regional details of land use change and degradation from livestock overload," explains Jinfeng Chang who led this study at IIASA and is now based at Zhejiang University in China. "We also looked at the effect of fires, and soil carbon losses by water erosion; CHThe study shows that emissions of CH"Our results show that the different human activities that have affected grasslands have shifted the balance of greenhouse gas removals and emissions more towards warming in intensively exploited pastures, and more towards cooling in natural and semi-natural systems. Coincidently, until recently the two types of grasslands have almost been canceling each other out," notes coauthor Thomas Gasser from IIASA. "However, the recent trends we see towards the expansion of pasture land and higher livestock numbers lead us to expect that global grasslands will accelerate climate warming if better policies are not put in place to favor soil carbon increases, stop deforestation for ranching, and develop climate-smart livestock production systems."According to the authors, the cooling services provided by sparsely grazed or wild grasslands, makes it clear that countries should assess not only the greenhouse gas budgets of their managed pastures (such as specified in the current national greenhouse gas reporting rules of the UN's Framework Convention on Climate Change), but also the sinks and sources of sparsely grazed rangelands, steppes, tundra, and wild grasslands. Full greenhouse gas reporting for each country could facilitate the assessment of progress towards the goals of the Paris Agreement and better link national greenhouse gas budgets to the observed growth rates of emissions in the atmosphere."In the context of low-warming climate targets, the mitigating or amplifying role of grasslands will depend on a number of aspects. This includes future changes in grass-fed livestock numbers; the stability of accumulated soil carbon in grasslands; and whether carbon storage can be further increased over time or if it will saturate, as observed in long-term experiments," concludes Philippe Ciais, a study coauthor from the Laboratory for Sciences of Climate and Environment (LSCE). | Climate | 2,021 |
January 4, 2021 | https://www.sciencedaily.com/releases/2021/01/210104170104.htm | Reawakened geyser does not foretell Yellowstone volcanic eruptions | When Yellowstone National Park's Steamboat Geyser -- which shoots water higher than any active geyser in the world -- reawakened in 2018 after three and a half years of dormancy, some speculated that it was a harbinger of possible explosive volcanic eruptions within the surrounding geyser basin. These so-called hydrothermal explosions can hurl mud, sand and rocks into the air and release hot steam, endangering lives; such an explosion on White Island in New Zealand in December 2019 killed 22 people. | A new study by geoscientists who study geysers throws cold water on that idea, finding few indications of underground magma movement that would be a prerequisite to an eruption. The geysers sit just outside the nation's largest and most dynamic volcanic caldera, but no major eruptions have occurred in the past 70,000 years."Hydrothermal explosions -- basically hot water exploding because it comes into contact with hot rock -- are one of the biggest hazards in Yellowstone," said Michael Manga, professor of earth and planetary sciences at the University of California, Berkeley, and the study's senior author. "The reason that they are problematic is that they are very hard to predict; it is not clear if there are any precursors that would allow you to provide warning."He and his team found that, while the ground around the geyser rose and seismicity increased somewhat before the geyser reactivated and the area currently is radiating slightly more heat into the atmosphere, no other dormant geysers in the basin have restarted, and the temperature of the groundwater propelling Steamboat's eruptions has not increased. Also, no sequence of Steamboat eruptions other than the one that started in 2018 occurred after periods of high seismic activity."We don't find any evidence that there is a big eruption coming. I think that is an important takeaway," he said.The study will be published this week in Manga, who has studied geysers around the world and created some in his own laboratory, set out with his colleagues to answer three main questions about Steamboat Geyser: Why did it reawaken? Why is its period so variable, ranging from 3 to 17 days? and Why does it spurt so high?The team found answers to two of those questions. By comparing the column heights of 11 different geysers in the United States, Russia, Iceland and Chile with the estimated depth of the reservoir of water from which their eruptions come, they found that the deeper the reservoir, the higher the eruption jet. Steamboat Geyser, with a reservoir about 25 meters (82 feet) below ground, has the highest column -- up to 115 meters, or 377 feet -- while two geysers that Manga measured in Chile were among the lowest -- eruptions about a meter (3 feet) high from reservoirs 2 and 5 meters below ground."What you are really doing is you are filling a container, it reaches a critical point, you empty it and then you run out of fluid that can erupt until it refills again," he said. "The deeper you go, the higher the pressure. The higher the pressure, the higher the boiling temperature. And the hotter the water is, the more energy it has and the higher the geyser."To explore the reasons for Steamboat Geyser's variability, the team assembled records related to 109 eruptions going back to its reactivation in 2018. The records included weather and stream flow data, seismometer and ground deformation readings, and observations by geyser enthusiasts. They also looked at previous active and dormant periods of Steamboat and nine other Yellowstone geysers, and ground surface thermal emission data from the Norris Geyser Basin.They concluded that variations in rainfall and snow melt were probably responsible for part of the variable period, and possibly for the variable period of other geysers as well. In the spring and early summer, with melting snow and rain, the underground water pressure pushes more water into the underground reservoir, providing more hot water to erupt more frequently. During winter, with less water, lower groundwater pressure refills the reservoir more slowly, leading to longer periods between eruptions. Because the water pushed into the reservoir comes from places even deeper than the reservoir, the water is decades or centuries old before it erupts back to the surface, he said.In October, Manga's team members demonstrated the extreme impact water shortages and drought can have on geysers. They showed that Yellowstone's iconic Old Faithful Geyser stopped erupting entirely for about 100 years in the 13th and 14th centuries, based on radiocarbon dating of mineralized lodgepole pine trees that grew around the geyser during its dormancy. Normally the water is too alkaline and the temperature too high for trees to grow near active geysers. The dormancy period coincided with a lengthy warm, dry spell across the Western U.S. called the Medieval Climate Anomaly, which may have caused the disappearance of several Native American civilizations in the West."Climate change is going to affect geysers in the future," Manga said.Manga and his team were unable to determine why Steamboat Geyser started up again on March 15, 2018, after three years and 193 days of inactivity, though the geyser is known for being far more variable than Old Faithful, which usually goes off about every 90 minutes. They could find no definitive evidence that new magma rising below the geyser caused its reactivation.The reactivation may have to do with changes in the internal plumbing, he said. Geysers seem to require three ingredients: heat, water and rocks made of silica -- silicon dioxide. Because the hot water in geysers continually dissolves and redeposits silica -- every time Steamboat Geyser erupts, it brings up about 200 kilograms, or 440 pounds of dissolved silica. Some of this silica is deposited underground and may change the plumbing system underneath the geyser. Such changes could temporarily halt or reactivate eruptions if the pipe gets rerouted, he said.Manga has experimented with geysers in his lab to understand why they erupt periodically, and at least in the lab, it appears to be caused by loops or side chambers in the pipe that trap bubbles of steam that slowly dribble out, heating the water column above until all the water can boil from the top down, explosively erupting in a column of water and steam.Studies of water eruptions from geysers could give insight into the eruptions of hot rock from volcanoes, he said."What we asked are very simple questions and it is a little bit embarrassing that we can't answer them, because it means there are fundamental processes on Earth that we don't quite understand," Manga said. "One of the reasons we argue we need to study geysers is that if we can't understand and explain how a geyser erupts, our hope for doing the same thing for magma is much lower." | Climate | 2,021 |
January 4, 2021 | https://www.sciencedaily.com/releases/2021/01/210104131950.htm | New tool for reconstructing ancient sea ice to study climate change | Sea ice is a critical indicator of changes in the Earth's climate. A new discovery by Brown University researchers could provide scientists a new way to reconstruct sea ice abundance and distribution information from the ancient past, which could aid in understanding human-induced climate change happening now. | In a study published in "We've shown that this molecule is a strong proxy for sea ice concentration," said Karen Wang, a Ph.D. student at Brown and lead author of the research. "Looking at the concentration of this molecule in sediments of different ages could allow us to reconstruct sea ice concentration through time."Other types of alkenone molecules have been used for years as proxies for sea surface temperature. At different temperatures, algae that live on the sea surface make differing amounts of alkenones known as C37:2 and C37:3. Scientists can use the ratios between those two molecules found in sea sediments to estimate past temperature. C37:4 -- the focus of this new study -- had been long considered a bit of problem for temperature measurements. It turns up in sediments taken from closer to the Arctic, throwing off the C37:2/C37:3 ratios."That was mostly what the C37:4 alkenone was known for -- throwing off the temperature ratios," said Yongsong Huang, principal investigator of the National Science Foundation-funded project and a professor in Brown's Department of Earth, Environmental and Planetary Science. "Nobody knew where it came from, or whether it was useful for anything. People had some theories, but no one knew for sure."To figure it out, the researchers studied sediment and sea water samples containing C37:4 taken from icy spots around the Arctic. They used advanced DNA sequencing techniques to identify the organisms present in the samples. That work yielded previously unknown species of algae from the order Isochrysidales. The researchers then cultured those new species in the lab and showed that they were indeed the ones that produced an exceptionally high abundance of C37:4.The next step was to see whether the molecules left behind by these ice-dwelling algae could be used as a reliable sea ice proxy. To do that, the researchers looked at concentrations of C37:4 in sediment cores from several spots in the Arctic Ocean near the present-day sea ice margins. In the recent past, sea ice in these spots is known to have been highly sensitive to regional temperature variation. That work found that the highest concentrations of C37:4 occurred when climate was coldest and ice was at its peak. The highest concentrations dated back to the Younger-Dryas, a period of very cold and icy conditions that occurred around 12,000 years ago. When climate was at its warmest and ice ebbed, C37:4 was sparse, the research found."The correlations we found with this new proxy were far stronger than other markers people use," said Huang, a research fellow at the Institute at Brown for Environment and Society. "No correlation will be perfect because modeling sea ice is a messy process, but this is probably about as strong as you're going to get."And this new proxy has some additional advantages over others, the researchers say. One other method for reconstructing sea ice involves looking for fossil remains of another kind of algae called diatoms. But that method becomes less reliable further back in time because fossil molecules can degrade. Molecules like C37:4 tend to be more robustly preserved, making them potentially better for reconstructions over deep time than other methods.The researchers plan to further research these new algae species to better understand how they become embedded in sea ice, and how they produce this alkenone compound. The algae appear to live in brine bubbles and channels inside sea ice, but it may also bloom just after the ice melts. Understanding those dynamics will help the researchers to better calibrate C37:4 as a sea ice proxy.Ultimately, the researchers hope that the new proxy will enable better understanding of sea ice dynamics through time. That information would improve models of past climate, which would make for better predictions of future climate change. | Climate | 2,021 |
January 4, 2021 | https://www.sciencedaily.com/releases/2021/01/210104114055.htm | Alert system shows potential for reducing deforestation, mitigating climate change | Forest loss declined 18% in African nations where a new satellite-based program provides free alerts when it detects deforestation activities. | A research collaboration that included Jennifer Alix-Garcia of Oregon State University found that the Global Land Analysis and Discovery System, known as GLAD, resulted in carbon sequestration benefits worth hundreds of millions of dollars in GLAD's first two years.Findings were published today in The premise of GLAD is simple: Subscribe to the system, launch a free web application, receive email alerts when the GLAD algorithm detects deforestation going on and then take action to save forests.GLAD, launched in 2016, delivers alerts created by the University of Maryland's Global Land Analysis and Discovery lab based on high-resolution satellite imaging from NASA's Landsat Science program. The information is made available to subscribers via the interactive web application, Global Forest Watch."Before GLAD, government agencies and other groups in the business of deforestation prevention had to lean on reports from volunteers or forest rangers," Alix-Garcia said. "Obviously the people making those reports can't be everywhere, which is a massive limitation for finding out about deforestation activity in time to prevent it."Changes in land use make a huge difference in how much carbon dioxide reaches the atmosphere and warms the planet, said Alix-Garcia, an economist in OSU's College of Agricultural Sciences."Reforestation is good, but avoiding deforestation is way better -- almost 10 times better in some instances," she said. "That's part of why cost-effective reduction of deforestation ought to be part of the foundation of global climate change mitigation strategies."Deforestation, Alix-Garcia adds, is a key factor behind the 40% increase in atmospheric carbon dioxide since the dawn of the industrial age, which in turn is contributing heavily to a warming planet. According to the National Oceanic and Atmospheric Administration, the global average atmospheric carbon dioxide concentration in 2018 was 407.4 parts per million, higher than at any time in at least 800,000 years.The annual rate of increase in atmospheric COAlix-Garcia, study leader Fanny Moffette of the University of Wisconsin and collaborators at the University of Maryland and the World Resources Institute looked at deforestation in 22 nations in the tropics in South America, Africa and Asia between 2011 and 2018 -- the last five years before GLAD and first two years after.In Africa, the results were telling: Compared to the prior five years, the first two years of GLAD showed 18% less forest loss where forest protectors were subscribing to the system.Using a concept known as the social cost of carbon -- the marginal cost to society of each additional metric ton of greenhouse gas that reaches the atmosphere -- researchers estimate the alert system was worth between $149 million and $696 million in Africa those two years.There was no substantial change in deforestation in Asia or South America, however, but possible explanations for that are numerous and suggest GLAD can make a greater difference in those places in years to come, the researchers say."We think that we see an effect mainly in Africa due to two main reasons," Moffette said. "One is because GLAD added more to efforts in Africa than on other continents, in the sense that there was already some evidence of countries using monitoring systems in countries like Indonesia and Peru. And Colombia and Venezuela, which are a large part of our sample, had significant political unrest during this period."The GLAD program is still young and as more groups sign up to receive alerts and decide how to intervene in deforestation, the system's influence may grow, she added."Now that we know subscribers of alerts can have an effect on deforestation, there are ways in which our work can potentially improve the training the subscribers receive and support their efforts," Moffette said. | Climate | 2,021 |
January 4, 2021 | https://www.sciencedaily.com/releases/2021/01/210104094651.htm | Pollutants rapidly changing the waters near Ieodo Island | There has been frequent occurrence of red tide in coastal waters around Korea where the sea turns red. Red tide is a phenomenon in which phytoplankton proliferate as nutrient or sewage flow into seawater, making it appear red. This not only causes damage to the fisheries industry but also affects the marine ecosystem. | Professor Kitack Lee and Ph.D. candidate Ji-Young Moon (first author) of POSTECH's Division of Environmental Science and Engineering have confirmed that the inflow of nitrogen pollutants since the 1980s has disturbed the nutrient balance in the northeast Asian waters and is changing the species of phytoplankton responsible for red tide. The team also found that the fastest change in the oceanic conditions caused by this inflow of nitrogen pollutants is happening in the waters near the Ieodo Ocean Research Station, located downstream of the Changjiang River of China. These findings were recently introduced in the journal The Northeast Asia region, including Korea, China, and Japan, has seen an increase of nitrogen pollutants because of the rapid population growth and industrialization in modern times. As the nitrogen pollutant flows into the sea as a result of floods and monsoons, northeast Asian waters have experienced an unexpected massive fertilization. Many scientists have warned that these nitrogen pollutants not only increase harmful algae bloom in the coastal waters, but also lead to deterioration of water quality and changes in the formation of marine ecosystem species.The researchers analyzed the nutrient concentration data and the occurrence of red tide in the East China seas and coastal waters of the Korean Peninsula in the past 40 years since the 1980s. The results show that a wide range of oceans in this region have changed from being nitrogen deficient to phosphorus (P) deficient, while at the same time the concentration of nitrate (N) has been higher than that of silicate (Si). In particular, it has been confirmed that the major phytoplankton in Korea's coastal waters are also changing from diatoms to dinoflagellates.The research team explained that this is direct evidence that the nutrient regime in the northeast Asian marginal sea is changing as the amount of nitrogen pollutants is increasing, which is further creating phytoplankton species and disrupting the marine ecosystem.At the same time, the team verified that the fastest place to see these oceanic changes due to the inflow of nitrogen pollutants was in the waters around Ieodo Ocean Research Station."Since the changes in the waters near Ieodo Ocean Research Station will soon occur in the waters near the Korean Peninsula, long-term observation of the concentration of nutrient in the coastal waters and changes in the ecosystem are necessary," proposed Professor Kitack Lee who led the study. He added, "The findings can be used as important scientific evidence for establishing environmental policies, such as setting nitrogen pollutant emissions."This study was conducted as part of the National Institute of Fisheries Science's Impact and Prediction of Oceanic Acidification due to Climate Change and the Korea Hydrographic and Oceanographic Agency's Ocean Carbon Circulation Response with Climate Change and the Interrelationship Study (IV).a) the physical variation in the ocean, b) the condition of seawater such as temperature, salinity, and density, etc.An excessively high level of nutrients in plankton as pollutants, including nitrogen, enter the sea from land.Inorganic elements necessary for the growth and proliferation of microorganisms that decompose organic matter during biological and chemical treatment of sewage. Chemicals that constitute skeletons of phytoplankton or algae and are constraints on the synthesis of their organic materials. | Climate | 2,021 |
January 4, 2021 | https://www.sciencedaily.com/releases/2021/01/210104075847.htm | How to identify heat-stressed corals | Researchers have found a novel way to identify heat-stressed corals, which could help scientists pinpoint the coral species that need protection from warming ocean waters linked to climate change, according to a Rutgers-led study. | "This is similar to a blood test to assess human health," said senior author Debashish Bhattacharya, a Distinguished Professor in the Department of Biochemistry and Microbiology in the School of Environmental and Biological Sciences at Rutgers University-New Brunswick. "We can assess coral health by measuring the metabolites (chemicals created for metabolism) they produce and, ultimately, identify the best interventions to ensure reef health. Coral bleaching from warming waters is an ongoing worldwide ecological disaster. Therefore, we need to develop sensitive diagnostic indicators that can be used to monitor reef health before the visible onset of bleaching to allow time for preemptive conservation efforts."Coral reefs provide habitat, nursery and spawning grounds for fish, food for about 500 million people along with their livelihoods, and coastline protection from storms and erosion. But global climate change threatens corals by warming ocean waters, resulting in coral bleaching and disease. Other threats to corals include sea-level rise, a more acidic ocean, unsustainable fishing, damage from vessels, invasive species, marine debris and tropical cyclones, according to the National Oceanic and Atmospheric Administration.The study, published in the journal Scientists subjected the heat-resistant "Our work, for the first time, identified a variety of novel and known metabolites that may be used as diagnostic indicators for heat stress in wild coral before or in the early stages of bleaching," Bhattacharya said.The scientists are validating their coral diagnosis results in a much larger study and the results look promising. The scientists are also developing a "coral hospital" featuring a new lab-on-a-chip device, which could check coral health in the field via metabolite and protein indicators. | Climate | 2,021 |
December 30, 2020 | https://www.sciencedaily.com/releases/2020/12/201230094229.htm | Largest study of Asia's rivers unearths 800 years of paleoclimate patterns | 813 years of annual river discharge at 62 stations, 41 rivers in 16 countries, from 1200 to 2012. That is what researchers at the Singapore University of Technology and Design (SUTD) produced after two years of research in order to better understand past climate patterns of the Asian Monsoon region. | Home to many populous river basins, including ten of the world's biggest rivers, the Asian Monsoon region provides water, energy, and food for more than three billion people. This makes it crucial for us to understand past climate patterns so that we can better predict long term changes in the water cycle and the impact they will have on the water supply.To reconstruct histories of river discharge, the researchers relied on tree rings. An earlier study by Cook et al. (2010) developed an extensive network of tree ring data sites in Asia and created a paleodrought record called the Monsoon Asia Drought Atlas (MADA). SUTD researchers used the MADA as an input for their river discharge model.They developed an innovative procedure to select the most relevant subset of the MADA for each river based on hydroclimatic similarity. This procedure allowed the model to extract the most important climate signals that influence river discharge from the underlying tree ring data."Our results reveal that rivers in Asia behave in a coherent pattern. Large droughts and major pluvial periods have often occurred simultaneously in adjacent or nearby basins. Sometimes, droughts stretched as far as from the Godavari in India to the Mekong in Southeast Asia. This has important implications for water management, especially when a country's economy depends on multiple river basins, like in the case of Thailand," explained first author Nguyen Tan Thai Hung, a PhD student from SUTD.Using modern measurements, it has been known that the behaviour of Asian rivers is influenced by the oceans. For instance, if the Pacific Ocean becomes warmer in its tropical region in an El Nino event, this will alter atmospheric circulations and likely cause droughts in South and Southeast Asian rivers. However, the SUTD study revealed that this ocean-river connection is not constant over time. The researchers found that rivers in Asia were much less influenced by the oceans in the first half of the 20th century compared to the 50 years before and 50 years after that period."This research is of great importance to policy makers; we need to know where and why river discharge changed during the past millennium to make big decisions on water-dependent infrastructure. One such example is the development of the ASEAN Power Grid, conceived to interconnect a system of hydropower, thermoelectric, and renewable energy plants across all ASEAN countries. Our records show that 'mega-droughts' have hit multiple power production sites simultaneously, so we can now use this information to design a grid that is less vulnerable during extreme events," said principal investigator Associate Professor Stefano Galelli from SUTD. | Climate | 2,020 |
December 28, 2020 | https://www.sciencedaily.com/releases/2020/12/201228165818.htm | Surveys identify relationship between waves, coastal cliff erosion | Scripps Institution of Oceanography at UC San Diego researchers have uncovered how rain and waves act on different parts of coastal cliffs. | Following three years of cliff surveys in and near the coastal city of Del Mar, Calif., they determined that wave impacts directly affect the base, and rain mostly impacts the upper region of the cliffs.The study appears in the journal "It's something that I've been trying to quantify for a long time, which is exciting," said coastal geomorphologist Adam Young, who is the lead author on the paper. "We've always known that waves were an important part of the cliff erosion process, but we haven't been able to separate the influence of waves and rain before."After decades of debate over the differing roles that waves and rain play in cliff erosion, the findings provide a new opportunity to improve forecasts, which is a pressing issue both in Del Mar and across the California coast. For example, neighborhoods and a railroad line the cliff edge in Del Mar. Past episodes of cliff failures have resulted in several train derailments and landslides, which trigger temporary rail closures and emergency repairs. The consequences can be costly.Prior to Young's study, the exact relationship between waves, rain, and cliff failures were unclear, mostly because it is difficult to measure the impacts of waves on the cliff base."Anytime a study involves sensors in the coastal zone, it's a challenge," said Young. For example, his team at Scripps Oceanography's Center for Climate Change Impacts and Adaptation buries sensors in the sand that measure wave energy. Big surf and erosion can shift the sensors and prevent scientists from collecting reliable measurements.The key to their success, according to Young, was to visit and measure the cliffs every week for three years -- an effort that was among the most detailed ever undertaken for studying coastal cliffs. These records along the 1.5 mile-long stretch in Del Mar allowed Young's team to untangle the effects of rainfall and groundwater runoff from wave impacts."We can now better predict how much erosion will occur during a particular storm using the wave and rainfall erosion relationship that we've identified here," said Young.Young's group combined measurements from the sensors buried in the sand with computer models of wave energy, as well as with three-dimensional maps of the beach and cliffs collected using a LiDAR device -- a laser mapping tool -- that was mounted onto trucks driven along the beach. The team also analyzed rainfall data from a local Del Mar weather station.Because rainfall and associated elevated groundwater levels trigger larger landslides, cliff erosion generally appears to be more correlated with rain. Teasing out the wave-driven cliff erosion is a more subtle and difficult process, but important because the wave-driven erosion weakens the cliff base and sets the stage for those rain-driven landslides.Understanding the way that cliffs and waves behave together will help improve short-term models that forecast cliff retreat, but the researchers will need more information to predict how future rainfall and waves will drive cliff erosion in the long term.Young and his group plan to continue to collect data in Del Mar, and are developing a website to make the information about the conditions leading to coastal landslides readily available. | Climate | 2,020 |
December 28, 2020 | https://www.sciencedaily.com/releases/2020/12/201228101803.htm | Carbon capture: Faster, greener way of producing carbon spheres | A fast, green and one-step method for producing porous carbon spheres, which are a vital component for carbon capture technology and for new ways of storing renewable energy, has been developed by Swansea University researchers. | The method produces spheres that have good capacity for carbon capture, and it works effectively at a large scale.Carbon spheres range in size from nanometers to micrometers. Over the past decade they have begun to play an important role in areas such as energy storage and conversion, catalysis, gas adsorption and storage, drug and enzyme delivery, and water treatment.They are also at the heart of carbon capture technology, which locks up carbon rather than emitting it into the atmosphere, thereby helping to tackle climate change.The problem is that existing methods of making carbon spheres have drawbacks. They can be expensive or impractical, or they produce spheres that perform poorly in capturing carbon. Some use biomass, making them more environmentally friendly, but they require a chemical to activate them.This is where the work of the Swansea team, based in the University's Energy Safety Research Institute, represents a major advance. It points the way towards a better, cleaner and greener way of producing carbon spheres.The team adapted an existing method known as CVD -- chemical vapour deposition. This involves using heat to apply a coating to a material. Using pyromellitic acid as both carbon and oxygen source, they applied the CVD method at different temperatures, from 600-900 °C. They then studied how efficiently the spheres were capturing COThey found that:This new approach brings several advantages over existing methods of producing carbon spheres. It is alkali-free and it doesn't need a catalyst to trigger the shaping of the spheres. It uses a cheap and safe feedstock which is readily available in the market. There is no need for solvents to purify the material. It is also a rapid and safe procedure.Dr Saeid Khodabakhshi of the Energy Safety Research Institute at Swansea University, who led the research, said:"Carbon spheres are fast becoming vital products for a green and sustainable future. Our research shows a green and sustainable way of making them.We demonstrated a safe, clean and rapid way of producing the spheres. Crucially, the micropores in our spheres means they perform very well in capturing carbon. Unlike other CVD methods, our procedure can produce spheres at large scale without relying on hazardous gas and liquid feedstocks.Carbon spheres are also being examined for potential use in batteries and supercapacitors. So in time, they could become essential to renewable energy storage, just as they already are for carbon capture." | Climate | 2,020 |
December 23, 2020 | https://www.sciencedaily.com/releases/2020/12/201223142443.htm | Capturing 40 years of climate change for an endangered Montana prairie | Over 40 years of monitoring, an endangered bunchgrass prairie became hotter, drier and more susceptible to fire annually -- but dramatic seasonal changes (not annual climate trends) seem to be driving the biggest changes in plant production, composition, and summer senescence. Gary Belovsky and Jennifer Slade of The University of Notre Dame, Indiana, present these findings in the open-access journal | Intermountain bunchgrass prairie is one of North America's most endangered ecosystems, now covering less than 1 percent of the area it once did. Over the past century, bunchgrass prairies have become warmer and drier, and human-driven climate change is expected to continue that trend, with potential impacts on bunchgrass ecosystems. However, bunchgrass is often overlooked in studies of grasslands.To better understand the effects of climate change on bunchgrass prairies, Belovsky and Slade studied the National Bison Range, a bunchgrass prairie in Montana, for 40 years. They made repeated observations of plant growth and production, abundances of different plant species, and availability of nitrogen (an important nutrient for plants), generating a comprehensive timeline of ecosystem changes.Over the course of the study, annual temperatures rose and precipitation declined in the prairie, making it more susceptible to fire. Surprisingly, the researchers found that annual aboveground primary production -- the amount of plant material produced every year -- rose by 110 percent, associated with increased precipitation and cooler temperatures during the important growth period of late May through June. However, this was associated with a change in plant composition, with a 108 percent increase in invasive species, more drought-tolerant species being favored overall, and declines in dicot non-grass plants (decreasing by 65 percent) over the 40-year study period.The researchers also found that other ecosystem changes followed seasonal climate trends, instead of annual trends. For instance, summer temperatures were higher than might be expected from annual trends, boosting summer senescence -- the yearly "browning" of green plant material.These findings highlight the importance of considering local and seasonal changes when forecasting the effects of climate change on a given ecosystem. The authors report that intermountain bunchgrass prairie could be morphing into a different type of grassland that may be previously unknown.Dr. Belovsky adds: "Forecasting climate change effects on plant production based on expected average annual increased temperature and decreased precipitation may not be appropriate, because seasonal climate changes may be more important and may not follow average annual expectations." | Climate | 2,020 |
December 23, 2020 | https://www.sciencedaily.com/releases/2020/12/201223091540.htm | Climate crisis is causing lakes to shrink | While global sea levels are rising due to the climate crisis and threatening near-coastal infrastructures, higher temperatures in other areas are having exactly the opposite effect. The water levels are falling and also causing massive problems. Although the consequences are equally serious, however, declining water levels are receiving less attention according to Matthias Prange, Thomas Wilke of the Justus Liebig University in Gießen, and Frank P. Wesselingh of the University of Utrecht and the Naturalis Biodiversity Center Leiden (the Netherlands). | "The Caspian Sea can be viewed as representative of many other lakes in the world. Many people are not even aware that an inland lake is dramatically shrinking due to climate change, as our models indicate," says Matthias Prange. The report of the Intergovernmental Panel on Climate Change (IPCC) also failed to mention lakes, and disregarded the social, political and economic consequences of global warming on the affected regions. "This has to change. We need more studies and a better understanding of the consequences of global warming in this region." The goal must be to raise awareness of the consequences of climate change for inland seas and lakes so that appropriate strategies can be developed, including approaches for other large lakes and regions facing similar challenges.Because of its size (it is the largest lake in the world) and because of its relatively high salinity of about one per cent, which is about one-third of the salt concentration in the oceans, the Caspian has been named a 'Sea'. Its largest inflow is the Volga River and it has no natural connection to the ocean. The water level is determined by the proportional influences of inflow, precipitation and evaporation. Global warming is causing increased evaporation, which results in a declining water level.The Caspian Sea is an important regional water reservoir and, despite its salt content, a biological and commercial center. It is bounded by Kazakhstan, Turkmenistan, Iran, Azerbaijan and Russia. Depending on the degree of global warming in the future, the water level could fall by 9 to 18 meters during this century. "This would affect not only the biodiversity, various species, and habitats that would disappear. The economies of all the bordering countries would be impacted, including harbors, fisheries and fish farming." For this reason, the authors argue that in the future the Caspian Sea should be used as an example in scientific research to assess the vulnerability of certain regions to falling water levels. Because no nation can solve the resulting conflicts alone, they propose a global task force to develop and coordinate strategies. The article suggests that "international climate funds" could offer a possibility for financing projects and adaptation measures if changes in the lake level are attributed to climate change. | Climate | 2,020 |
December 22, 2020 | https://www.sciencedaily.com/releases/2020/12/201222132037.htm | Pandemic and forthcoming stimulus funds could bring climate targets in sight -- or not | The lockdowns that resulted from the COVID-19 pandemic have reduced greenhouse gas emissions. However, in the recovery phase, emissions could rise to levels above those projected before the pandemic. It all depends on how the stimulus money that governments inject into their economies is spent. A team of scientists, led by Dr Yuli Shan and Professor Klaus Hubacek from the University of Groningen, has quantified how different recovery scenarios may affect global emissions and climate change. Their results were published in | The worldwide recession caused by the coronavirus has had a profound impact on greenhouse gas emissions that is likely to continue in the coming years. "The decline in 2020 might bring us back to the levels of 2006-2007," says Yuli Shan, an environmental scientist at the University of Groningen and first author of the paper. The COShan and his colleagues from the Netherlands, the UK and China used a recently developed economic impact model to calculate the direct and indirect effects from the lockdowns, but also the effects of stimuli in different scenarios. These calculations were performed for economies in 41 countries, representing some 90 per cent of the global economy. "We did this for entire global supply chains,' explains Shan. 'For example, if China has to stop producing certain goods, this could also impact production in the US or in Europe."The calculations were performed for allocation of the stimuli to five different economic categories (construction, manufacturing, service sector, health sector and households) and for different policy aims. "These vary in the amount of carbon emissions that they will produce," explains Shan. The results of the different scenarios were then quantified in terms of greenhouse gas emissions."The models show that without structural change, we will see a V-shaped response," says Hubacek. In that case, the emissions will quickly increase to pre-crisis levels and perhaps even exceed those levels. "Our results show how far apart the different scenarios can bring us." Emissions could drop by 6.6 gigatons of carbon (-4.7 per cent) or increase by 23.2 gigatons (+12.1 per cent). "There is plenty of room to go the wrong way," says Hubacek. "And a crisis is a terrible thing to waste."Stimulus packages should target innovations, support the energy transition and help households to invest in the adoption of renewable energy. "Spending this money to bail out carbon-intensive sectors such as airlines is heading in the wrong direction. It is much better to improve public transport and railways." Hubacek's message is that the COVID-19 crisis has made a big dent in greenhouse gas emissions and that we should use this for our benefit. "This crisis is awful, but it is also a wake-up call for action against climate change. We are now in a position to really do something about it."However, there is also a big risk: governments must borrow billions for the stimulus packages. The increases in national debts leave little space for further investments in the next few decades. "So, if we do not invest in low-carbon alternatives now, it will not happen for a long time." This would mean that greenhouse gas emissions could increase beyond what was predicted before the pandemic."Our next project is to study the EU economy in greater detail, but still embedded in the global model. So, we will look at entire production chains." Hubacek hopes that governments will make the right choices. "At the moment, it can go either way: we can increase global warming or slow it down substantially." | Climate | 2,020 |
December 22, 2020 | https://www.sciencedaily.com/releases/2020/12/201222131951.htm | New imaging method views soil carbon at near-atomic scales | The Earth's soils contain more than three times the amount of carbon than is found in the atmosphere, but the processes that bind carbon in the soil are still not well understood. | Improving such understanding may help researchers develop strategies for sequestering more carbon in soil, thereby keeping it out of the atmosphere where it combines with oxygen and acts as a greenhouse gas.A new study describes a breakthrough method for imaging the physical and chemical interactions that sequester carbon in soil at near atomic scales, with some surprising results.The study, "Organo-organic and Organo-mineral Interfaces in Soil at the Nanometer Scale," was published Nov. 30 in At that resolution, the researchers showed -- for the first time -- that soil carbon interacts with both minerals and other forms of carbon from organic materials, such as bacterial cell walls and microbial byproducts. Previous imaging research had only pointed to layered interactions between carbon and minerals in soils."If there is an overlooked mechanism that can help us retain more carbon in soils, then that will help our climate," said senior author Johannes Lehmann, the Liberty Hyde Bailey Professor in the School of Integrative Plant Science, Soil and Crop Sciences Section, in the College of Agriculture and Life Sciences. Angela Possinger Ph.D. '19, who was a graduate student in Lehmann's lab and is currently a postdoctoral researcher at Virginia Tech University, is the paper's first author.Since the resolution of the new technique is near atomic scale, the researchers are not certain what compounds they are looking at, but they suspect the carbon found in soils is likely from metabolites produced by soil microbes and from microbial cell walls. "In all likelihood, this is a microbial graveyard," Lehmann said."We had an unexpected finding where we could see interfaces between different forms of carbon and not just between carbon and minerals," Possinger said. "We could start to look at those interfaces and try to understand something about those interactions."The technique revealed layers of carbon around those organic interfaces. It also showed that nitrogen was an important player for facilitating the chemical interactions between both organic and mineral interfaces, Possinger said.As a result, farmers may improve soil health and mitigate climate change through carbon sequestration by considering the form of nitrogen in soil amendments, she said.While pursuing her doctorate, Possinger worked for years with Cornell physicists -- including co-authors Lena Kourkoutis, associate professor of applied and engineering physics, and David Muller, the Samuel B. Eckert Professor of Engineering in Applied and Engineering Physics, and the co-director of the Kavli Institute at Cornell for Nanoscale Science -- to help develop the multi-step method.The researchers planned to use powerful electron microscopes to focus electron beams down to sub-atomic scales, but they found the electrons modify and damage loose and complex soil samples. As a result, they had to freeze the samples to around minus 180 degrees Celsius, which reduced the harmful effects from the beams."We had to develop a technique that essentially keeps the soil particles frozen throughout the process of making very thin slices to look at these tiny interfaces," Possinger said.The beams could then be scanned across the sample to produce images of the structure and chemistry of a soil sample and its complex interfaces, Kourkoutis said."Our physics colleagues are leading the way globally to improve our ability to look very closely into material properties," Lehmann said. "Without such interdisciplinary collaboration, these breakthroughs are not possible.."The new cryogenic electron microscopy and spectroscopy technique will allow researchers to probe a whole range of interfaces between soft and hard materials, including those that play roles in the function of batteries, fuel cells and electrolyzers, Kourkoutis said.Coauthors include Michael Zachman Ph.D. '18, a former graduate student in Kourkoutis' lab; Akio Enders, a former researcher in Lehmann's lab; and Barnaby Levin Ph.D. '17, a former graduate student in Muller's lab.The study was funded by the National Science Foundation, the Technical University of Munich Institute for Advanced Study, the Andrew W. Mellon Foundation and the Cornell College of Agriculture and Life Sciences Alumni Foundation. | Climate | 2,020 |
December 22, 2020 | https://www.sciencedaily.com/releases/2020/12/201222081307.htm | A groggy climate giant: Subsea permafrost is still waking up after 12,000 years | In the far north, the swelling Arctic Ocean inundated vast swaths of coastal tundra and steppe ecosystems. Though the ocean water was only a few degrees above freezing, it started to thaw the permafrost beneath it, exposing billions of tons of organic matter to microbial breakdown. The decomposing organic matter began producing CO | Though researchers have been studying degrading subsea permafrost for decades, difficulty collecting measurements and sharing data across international and disciplinary divides have prevented an overall estimate of the amount of carbon and the rate of release. A new study, led by Ph.D. candidate Sara Sayedi and senior researcher Dr. Ben Abbott at Brigham Young University (BYU) published in IOP Publishing journal Sayedi and an international team of 25 permafrost researchers worked under the coordination of the Permafrost Carbon Network (PCN), which is supported by the U.S. National Science Foundation. The researchers combined findings from published and unpublished studies to estimate the size of the past and present subsea carbon stock and how much greenhouse gas it might produce over the next three centuries.Using a methodology called expert assessment, which combines multiple, independent plausible values, the researchers estimated that the subsea permafrost region currently traps 60 billion tons of methane and contains 560 billion tons of organic carbon in sediment and soil. For reference, humans have released a total of about 500 billion tons of carbon into the atmosphere since the Industrial Revolution. This makes the subsea permafrost carbon stock a potential giant ecosystem feedback to climate change."Subsea permafrost is really unique because it is still responding to a dramatic climate transition from more than ten thousand years ago," Sayedi said. "In some ways, it can give us a peek into the possible response of permafrost that is thawing today because of human activity."Estimates from Sayedi's team suggest that subsea permafrost is already releasing substantial amounts of greenhouse gas. However, this release is mainly due to ancient climate change rather than current human activity. They estimate that subsea permafrost releases approximately 140 million tons of COThe researchers found that if human-caused climate change continues, the release of CH"These results are important because they indicate a substantial but slow climate feedback," Sayedi explained. "Some coverage of this region has suggested that human emissions could trigger catastrophic release of methane hydrates, but our study suggests a gradual increase over many decades."Even if this climate feedback is relatively gradual, the researchers point out that subsea permafrost is not included in any current climate agreements or greenhouse gas targets. Sayedi emphasized that there is still a large amount of uncertainty about subsea permafrost and that additional research is needed."Compared to how important subsea permafrost could be for future climate, we know shockingly little about this ecosystem," Sayedi said. "We need more sediment and soil samples, as well as a better monitoring network to detect when greenhouse gas release responds to current warming and just how quickly this giant pool of carbon will wake from its frozen slumber."This research was funded by the U.S. National Science Foundation and by BYU Graduate Studies. | Climate | 2,020 |
December 21, 2020 | https://www.sciencedaily.com/releases/2020/12/201221160459.htm | Muddying the waters: Weathering might remove less atmospheric carbon dioxide than thought | The weathering of rocks at the Earth's surface may remove less greenhouse gases from the atmosphere than previous estimates, says new research from the University of Cambridge. | The findings, published in The research also suggests there may be a previously unknown sink drawing COWeathering is the process by which atmospheric carbon dioxide breaks down rocks and then gets trapped in sediment. It is a major part of our planet's carbon cycle, shuttling carbon dioxide between the land, sea and air, and influencing global temperatures."Weathering is like a planetary thermostat -- it's the reason why Earth is habitable. Scientists have long suggested this is why we don't have a runaway greenhouse effect like on Venus," said lead author Ed Tipper from Cambridge's Department of Earth Sciences. By locking carbon dioxide away in sediments, weathering removes it from the atmosphere over long timescales, reducing the greenhouse effect and lowering global temperatures.The team's new calculations show that, across the globe, weathering fluxes have been overestimated by up to 28%, with the greatest impact on rivers in mountainous regions where rocks are broken down faster.They also report that three of the largest river systems on Earth, including the neighbouring Yellow and Salween Rivers with their origins on the Tibetan Plateau and the Yukon River of North America, do not absorb carbon dioxide over long timescales -- as had been thought.For decades the Tibetan plateau has been invoked as a long term sink for carbon and mediator of climate. Some 25% of the sediment in the world's oceans originate from the plateau."One of the best places to study the carbon cycle are rivers, they are the arteries of the continents. Rivers are the link between the solid Earth and oceans -- hauling sediments weathered from the land down to the oceans where their carbon is locked up in rocks," said Tipper."Scientists have been measuring the chemistry of river waters to estimate weathering rates for decades," said co-author Victoria Alcock "Dissolved sodium is one of the most commonly measured products of weathering -- but we've shown that it's not that simple, and in fact sodium often comes from elsewhere."Sodium is released when silicate minerals, the basic building blocks of most of Earth's rocks, dissolve in carbonic acid -- a mix of carbon dioxide in the atmosphere and rainwater.However, the team found not all sodium comes from this weathering process. "We've found an additional source of sodium in river waters across the globe," said co-author Emily Stevenson. "That extra sodium is not from weathered silicate rocks as other studies assume, but in fact from very old clays which are being eroded in river catchments."Tipper and his research group studied eight of the largest river systems on Earth, a mission involving 16 field seasons and thousands of lab analyses in search of where that extra sodium was coming from.They found the answer in a soupy 'gel' of clay and water -- known as the cation exchange pool -- which is carried along by muddy river sediment.The exchange pool is a reactive hive of cations -- positively charged ions like sodium -- which are weakly bonded to clay particles. The cations can easily swap out of the gel for other elements like calcium in river water, a process that can take just a few hours.Although it has been described in soils since the 1950s, the role the exchange pool plays in supplying sodium to rivers has been largely neglected."The chemical and isotopic makeup of the clays in the exchange pool tell us what they are made of and where they've come from," said co-author Alasdair Knight. "We know that many of the clays carried by these rivers come from ancient sediments, and we suggest that some of the sodium in the river must come from these clays."The clays were originally formed from continental erosion millions of years ago. On their journey downstream they harvested cations from the surrounding water -- their exchange pool picking up sodium on reaching the sea. Today, after being uplifted from the seafloor, these ancient clays -- together with their sodium -- are now being eroded by modern rivers.This old sodium, which can switch out of the clays in the exchange pool and into river water, has previously been mistaken as the dissolved remnants of modern weathering."Generating just one data point took a huge amount of work in the lab and we also had to do a lot of maths," said Stevenson. "It's like unmixing a cake, using a forensic approach to isolate key ingredients in the sediments, leaving behind the exchange pool and the clays. People have used the same methods for a really long time -- and they work -- but we've been able to find an extra ingredient that provides the sodium and we need to account for this.""It's thanks to the hard work of many collaborators and students over many years that our samples had the scope to get to grips with this complex chemical process at a global scale," said Tipper.Scientists are now left to puzzle over what else could be absorbing Earth's carbon dioxide over geological time. There are no certain candidates -- but one controversial possibility is that life is removing carbon from the atmosphere. Another theory is that silicate dissolution on the ocean floor or volcanic arcs may be important. "People have spent decades looking on the continents for weathering -- so maybe we now need to start expanding where we look," said Tipper. | Climate | 2,020 |
December 21, 2020 | https://www.sciencedaily.com/releases/2020/12/201221160425.htm | Climate change: Threshold for dangerous warming will likely be crossed between 2027-2042 | The threshold for dangerous global warming will likely be crossed between 2027 and 2042 -- a much narrower window than the Intergovernmental Panel on Climate Change's estimate of between now and 2052. In a study published in | Scientists have been making projections of future global warming using climate models for decades. These models play an important role in understanding the Earth's climate and how it will likely change. But how accurate are they?Climate models are mathematical simulations of different factors that interact to affect Earth's climate, such as the atmosphere, ocean, ice, land surface and the sun. While they are based on the best understanding of the Earth's systems available, when it comes to forecasting the future, uncertainties remain."Climate skeptics have argued that global warming projections are unreliable because they depend on faulty supercomputer models. While these criticisms are unwarranted, they underscore the need for independent and different approaches to predicting future warming," says co-author Bruno Tremblay, a professor in the Department of Atmospheric and Oceanic Sciences at McGill University.Until now, wide ranges in overall temperature projections have made it difficult to pinpoint outcomes in different mitigation scenarios. For instance, if atmospheric CO2 concentrations are doubled, the General Circulation Models (GCMs) used by the Intergovernmental Panel on Climate Change (IPCC), predict a very likely global average temperature increase between 1.9 and 4.5C -- a vast range covering moderate climate changes on the lower end, and catastrophic ones on the other."Our new approach to projecting the Earth's temperature is based on historical climate data, rather than the theoretical relationships that are imperfectly captured by the GCMs. Our approach allows climate sensitivity and its uncertainty to be estimated from direct observations with few assumptions," says co-author Raphael Hebert, a former graduate researcher at McGill University, now working at the Alfred-Wegener-Institut in Potsdam, Germany.In a study for "Now that governments have finally decided to act on climate change, we must avoid situations where leaders can claim that even the weakest policies can avert dangerous consequences," says co-author Shaun Lovejoy, a professor in the Physics Department at McGill University. "With our new climate model and its next generation improvements, there's less wiggle room." | Climate | 2,020 |
December 21, 2020 | https://www.sciencedaily.com/releases/2020/12/201221160419.htm | Volcanic eruptions directly triggered ocean acidification during Early Cretaceous | Around 120 million years ago, the earth experienced an extreme environmental disruption that choked oxygen from its oceans. | Known as oceanic anoxic event (OAE) 1a, the oxygen-deprived water led to a minor -- but significant -- mass extinction that affected the entire globe. During this age in the Early Cretaceous Period, an entire family of sea-dwelling nannoplankton virtually disappeared.By measuring calcium and strontium isotope abundances in nannoplankton fossils, Northwestern earth scientists have concluded the eruption of the Ontong Java Plateau large igneous province (LIP) directly triggered OAE1a. Roughly the size of Alaska, the Ontong Java LIP erupted for seven million years, making it one of the largest known LIP events ever. During this time, it spewed tons of carbon dioxide (CO"We go back in time to study greenhouse periods because Earth is headed toward another greenhouse period now," said Jiuyuan Wang, a Northwestern Ph.D. student and first author of the study. "The only way to look into the future is to understand the past."The study was published online last week (Dec. 16) in the journal Andrew Jacobson, Bradley Sageman and Matthew Hurtgen -- all professors of earth and planetary sciences at Northwestern's Weinberg College of Arts and Sciences -- coauthored the paper. Wang is co-advised by all three professors.Nannoplankton shells and many other marine organisms build their shells out of calcium carbonate, which is the same mineral found in chalk, limestone and some antacid tablets. When atmospheric COTo study the earth's climate during the Early Cretaceous, the Northwestern researchers examined a 1,600-meter-long sediment core taken from the mid-Pacific Mountains. The carbonates in the core formed in a shallow-water, tropical environment approximately 127 to 100 million years ago and are presently found in the deep ocean."When you consider the Earth's carbon cycle, carbonate is one of the biggest reservoirs for carbon," Sageman said. "When the ocean acidifies, it basically melts the carbonate. We can see this process impacting the biomineralization process of organisms that use carbonate to build their shells and skeletons right now, and it is a consequence of the observed increase in atmospheric COSeveral previous studies have analyzed the calcium isotope composition of marine carbonate from the geologic past. The data can be interpreted in a variety of ways, however, and calcium carbonate can change throughout time, obscuring signals acquired during its formation. In this study, the Northwestern researchers also analyzed stable isotopes of strontium -- a trace element found in carbonate fossils -- to gain a fuller picture."Calcium isotope data can be interpreted in a variety of ways," Jacobson said. "Our study exploits observations that calcium and strontium isotopes behave similarly during calcium carbonate formation, but not during alteration that occurs upon burial. In this study, the calcium-strontium isotope 'multi-proxy' provides strong evidence that the signals are 'primary' and relate to the chemistry of seawater during OAE1a.""Stable strontium isotopes are less likely to undergo physical or chemical alteration over time," Wang added. "Calcium isotopes, on the other hand, can be easily altered under certain conditions."The team analyzed calcium and strontium isotopes using high-precision techniques in Jacobson's clean laboratory at Northwestern. The methods involve dissolving carbonate samples and separating the elements, followed by analysis with a thermal ionization mass spectrometer. Researchers have long suspected that LIP eruptions cause ocean acidification. "There is a direct link between ocean acidification and atmospheric COBy understanding how oceans responded to extreme warming and increased atmospheric CO"The difference between past greenhouse periods and current human-caused warming is in the timescale," Sageman said. "Past events have unfolded over tens of thousands to millions of years. We're making the same level of warming (or more) happen in less than 200 years.""The best way we can understand the future is through computer modeling," Jacobson added. "We need climate data from the past to help shape more accurate models of the future." | Climate | 2,020 |
December 21, 2020 | https://www.sciencedaily.com/releases/2020/12/201221160411.htm | Invasive in the U.S., lifesaver Down Under | Ten years of research led by the University of South Florida has revealed that a monitor lizard should be regarded as an "ecosystem engineer," a rarity for reptiles. Tortoises and sea turtles are the only reptiles considered to be ecosystem engineers, a term used to describe organisms that have a great impact on their environment based on their ability to create, modify, maintain or destroy a habitat. Sean Doody, assistant professor and graduate director of integrative biology at the USF St. Petersburg campus, discovered that while a related species is considered invasive in the United States, in Australia, small animal communities rely on the monitor lizards' burrow system, called a warren, using it as a habitat, a place to forage for food and nesting. | In his study published in The timing of the research revealed clues as to why certain species utilized the warrens. For example, throughout the winter dry season, the researchers found hibernating frogs using the burrows to maintain their body moisture. During one excavation, Doody and his team discovered 418 individual frogs in a single warren."The finding is significant as it shows that nesting warrens provide critical shelter and other resources for the small animal community," Doody said. "The invasive cane toad is decimating the monitor lizards in some areas, meaning that these nesting warrens, which are re-used year after year, will disappear. This can impact the relative number of predators and prey, which can have unexpected consequences for the ecosystem, such as an overabundance of one species at the cost of another, which in other systems has threatened species with local extinction.The arrival of the toxic cane toad emphasized the extent of the monitor lizard's impact on the food web. In studies conducted between 2009 and 2017, Doody's research team uncovered abandoned burrows and an increase in the lizard's prey, including smaller lizards, snakes, turtles and birds. Australian researchers and natural resource managers have been unable to successfully control cane toads.Doody is now expanding his research to include the perentie, another large monitoring lizard that likely nests at great depths in the Australian desert, to see if it too should be deemed an ecological engineer. His team is also looking at how climate warming will impact the facilitation of these animal communities. | Climate | 2,020 |
December 21, 2020 | https://www.sciencedaily.com/releases/2020/12/201221134146.htm | CRISPR helps researchers uncover how corals adjust to warming oceans | The CRISPR/Cas9 genome editing system can help scientists understand, and possibly improve, how corals respond to the environmental stresses of climate change. Work led by Phillip Cleves -- who joined Carnegie's Department of Embryology this fall -- details how the revolutionary, Nobel Prize-winning technology can be deployed to guide conservation efforts for fragile reef ecosystems. | Cleves' research team's findings were recently published in two papers in the Corals are marine invertebrates that build extensive calcium carbonate skeletons from which reefs are constructed. But this architecture is only possible because of a mutually beneficial relationship between the coral and various species of single-celled algae that live inside individual coral cells. These algae convert the Sun's energy into food using a process called photosynthesis and they share some of the nutrients they produce with their coral hosts -- kind of like paying rent.Coral reefs have great ecological, economic, and aesthetic value. Many communities depend on them for food and tourism. However, human activity is putting strain on coral reefs including warming oceans, pollution, and acidification and that affects this symbiotic relationship."In particular, increasing ocean temperatures can cause coral to lose their algae, a phenomenon called bleaching, because the coral takes on a ghostly white look in the absence of the algae's pigment," Cleves explained. "Without the nutrients provided by photosynthesis, the coral can die of starvation."In 2018, Cleves headed up the team that demonstrated the first use of the CRISPR/Cas9 genome editing on coral. Now, his teams used CRISPR/Cas9 to identify a gene responsible for regulating coral's response to heat stress.Working first in the anemone Aiptasia, one team -- including Stanford University's Cory Krediet, Erik Lehnert, Masayuki Onishi, and John Pringle -- identified a protein, called Heat Shock Factor 1 (HSF1), which activates many genes associated with the response to heat stress. Anemones are close coral relatives that have similar symbiotic relationships with photosynthetic algae, but they grow faster and are easier to study. These traits make Aiptasia a powerful model system to study coral biology in the lab.Then another Cleves-led team -- including Stanford University's Amanda Tinoco and John Pringle, Queensland University of Technology's Jacob Bradford and Dimitri Perrin, and Line Bay of the Australian Institute of Marine Science (AIMS) -- used CRISPR/Cas9 to create mutations in the gene that encodes HSF1 in the coral Acropora millepora, demonstrating its importance for coping with a warming environment. Without a functioning HSF1 protein, the coral died rapidly when the surrounding water temperature increased."Understanding the genetic traits of heat tolerance of corals holds the key to understanding not only how corals will respond to climate change naturally but also balancing the benefits, opportunities and risks of novel management tools," said Bay, who is the AIMS principal research scientist and head of its Reef Recovery, Restoration and Adaptation team.Added Cleves: "Our work further demonstrates how CRISPR/Cas9 can be used to elucidate aspects of coral physiology that can be used to guide conservation. This time we focused on one particular heat tolerance gene, but there are so many more mechanisms to reveal in order to truly understand coral biology and apply this knowledge to protecting these important communities." | Climate | 2,020 |
December 21, 2020 | https://www.sciencedaily.com/releases/2020/12/201221121813.htm | The upside of volatile space weather | Although violent and unpredictable, stellar flares emitted by a planet's host star do not necessarily prevent life from forming, according to a new Northwestern University study. | Emitted by stars, stellar flares are sudden flashes of magnetic imagery. On Earth, the sun's flares sometimes damage satellites and disrupt radio communications. Elsewhere in the universe, robust stellar flares also have the ability to deplete and destroy atmospheric gases, such as ozone. Without the ozone, harmful levels of ultraviolet (UV) radiation can penetrate a planet's atmosphere, thereby diminishing its chances of harboring surface life.By combining 3D atmospheric chemistry and climate modeling with observed flare data from distant stars, a Northwestern-led team discovered that stellar flares could play an important role in the long-term evolution of a planet's atmosphere and habitability."We compared the atmospheric chemistry of planets experiencing frequent flares with planets experiencing no flares. The long-term atmospheric chemistry is very different," said Northwestern's Howard Chen, the study's first author. "Continuous flares actually drive a planet's atmospheric composition into a new chemical equilibrium.""We've found that stellar flares might not preclude the existence of life," added Daniel Horton, the study's senior author. "In some cases, flaring doesn't erode all of the atmospheric ozone. Surface life might still have a fighting chance."The study will be published on Dec. 21 in the journal Horton is an assistant professor of Earth and planetary sciences in Northwestern's Weinberg College of Arts and Sciences. Chen is a Ph.D. candidate in Horton's Climate Change Research Group and a NASA future investigator.All stars -- including our very own sun -- flare, or randomly release stored energy. Fortunately for Earthlings, the sun's flares typically have a minimal impact on the planet."Our sun is more of a gentle giant," said Allison Youngblood, an astronomer at the University of Colorado and co-author of the study. "It's older and not as active as younger and smaller stars. Earth also has a strong magnetic field, which deflects the sun's damaging winds."Unfortunately, most potentially habitable exoplanets aren't as lucky. For planets to potentially harbor life, they must be close enough to a star that their water won't freeze -- but not so close that water vaporizes."We studied planets orbiting within the habitable zones of M and K dwarf stars -- the most common stars in the universe," Horton said. "Habitable zones around these stars are narrower because the stars are smaller and less powerful than stars like our sun. On the flip side, M and K dwarf stars are thought to have more frequent flaring activity than our sun, and their tidally locked planets are unlikely to have magnetic fields helping deflect their stellar winds."Chen and Horton previously conducted a study of M dwarf stellar systems' long term climate averages. Flares, however, occur on an hours- or days-long timescales. Although these brief timescales can be difficult to simulate, incorporating the effects of flares is important to forming a more complete picture of exoplanet atmospheres. The researchers accomplished this by incorporating flare data from NASA's Transiting Exoplanet Satellite Survey, launched in 2018, into their model simulations.If there is life on these M and K dwarf exoplanets, previous work hypothesizes that stellar flares might make it easier to detect. For example, stellar flares can increase the abundance of life-indicating gasses (such as nitrogen dioxide, nitrous oxide and nitric acid) from imperceptible to detectable levels."Space weather events are typically viewed as a detriment to habitability," Chen said. "But our study quantitatively shows that some space weather can actually help us detect signatures of important gases that might signify biological processes."This study involved researchers from a wide range of backgrounds and expertise, including climate scientists, exoplanet scientists, astronomers, theorists and observers."This project was a result of fantastic collective team effort," said Eric T. Wolf, a planetary scientist at CU Boulder and a co-author of the study. "Our work highlights the benefits of interdisciplinary efforts when investigating conditions on extrasolar planets."The study was supported by the NASA Earth and Space Science and Technology Graduate Research Award (number 80NSSC19K1523). | Climate | 2,020 |
December 21, 2020 | https://www.sciencedaily.com/releases/2020/12/201221121756.htm | Coastal ecosystems 'bright spots' for repairing marine ecosystems | CSIRO, Australia's national science agency, has identified coastal 'bright spots' to repair marine ecosystems globally, paving the way to boost biodiversity, local economies and human wellbeing. | Doctor Megan Saunders, CSIRO Oceans and Atmosphere Senior Research Scientist, said successful coastal restoration efforts could be achieved over large areas, deliver positive impacts for decades, expand restored areas by up to 10-times in size, and generate jobs."Coastal ecosystems across the globe including saltmarshes, mangroves, seagrasses, oyster reefs, kelp beds and coral reefs have declined by up to 85 per cent over decades," Dr Saunders said."Identifying bright spots that have delivered successful coastal and marine restoration in the past enables us to apply this knowledge to help save marine areas that are struggling to recover from degradation."Re-establishing coastal marine ecosystems at large scales can support human health and wellbeing and boost the adaptation response to climate change."The research published today in the journal "A range of techniques have resulted in significant restoration of saltmarshes, coral reefs and seagrass meadows over extended periods of time," Dr Saunders said."In Australia, there are some really innovative examples of marine restoration."For example, CSIRO is harvesting coral larvae in the Great Barrier Reef to boost large-scale coral restoration efforts."Simple changes to how we plant saltmarshes have also resulted in doubled survivorship and biomass."At least 775 million people have a high dependency on coastal marine ecosystems.Coastal ecosystems help to remove carbon dioxide from the atmosphere and protect and stabilise shorelines.Coastal marine restoration is an important nature-based answer to the impacts of global climate change."Restoration of coastal marine ecosystems back to a healthy state is an important tool for responding to threats to the marine environment such as coastal development, land use change and overfishing," Dr Saunders said.The United Nations recognised the importance of the restoration and declared the Decade on Ecosystem Restoration to start from 2021.The UN panel for a Sustainable Ocean Economy also emphasised the need to undertake restoration and other nature-based approaches at large scales to restore and protect coastal ecosystems.Professor Brian Silliman, co-author and CSIRO Distinguished Fulbright Chair in Science and Technology and Professor at Duke University, USA, said 'bright spots' gave us the window to understand which restoration methods worked best so we could identify where to focus research efforts and investment to protect people's livelihoods."Investing into coastal restoration creates jobs and can be used as a strategy to boost economic recovery and coastal marine health," Professor Silliman said."Restoration of marine habitats, such as kelp forests and oyster reefs, has improved commercial and recreational fishing in some countries, which boosted the local economy."In the USA, the propagation and dispersal of seagrass seeds resulted in seagrass meadows recovering in areas where they had been lost many decades ago, removing an estimated 170 tonnes of nitrogen and 630 tonnes carbon per year from the atmosphere."In another study, recovery of reefs impacted by blast fishing in Indonesia has been achieved by placing rocks or other hard structures underwater to help with coral colonisation, with persistent growth of coral recorded for more than 14 years."Doctor Chris Gillies, The Nature Conservancy's Oceans Program Director and a co-author on the study, said demonstrating that projects could be successful was important for securing investment into restoration."We are starting to see more and more investment into marine restoration in Australia," Dr Gillies said."For example, the Australian Government recently invested $20 million into 'Reef Builder' to restore 20 of Australia's lost shellfish reefs."The study was a collaboration between CSIRO, Duke University, The Nature Conservancy, The University of Queensland, University of New South Wales and the Sydney Institute for Marine Science. | Climate | 2,020 |
December 21, 2020 | https://www.sciencedaily.com/releases/2020/12/201221101213.htm | Climate warming linked to tree leaf unfolding and flowering growing apart | An international team of researchers from the Chinese Academy of Sciences, Zhejiang A & F University and the University of Eastern Finland have found that regardless of whether flowering or leaf unfolding occurred first in a species, the first event advanced more than the second over the last seven decades. | In the four European tree species the researchers looked at: horse chestnut, scots pine, alder and ash, the time interval between leaf unfolding and flowering increased at a rate of 0.6 to 1.3 days per decade between 1950 -- 2013. Similar trends were seen geographically, with the time interval between the two life-cycle (phenological) events being greater in trees in warmer areas of Europe.Although leaf unfolding and flowering have both been shown to be happening earlier with climate warming, this is the first large scale study to examine both phenological events together and show that they are not advancing at the same rate in response to climate warming.Leaf unfolding and flowering are key annual events for trees with each signalling the start of growth and reproduction, respectively. The timing of these events is crucial for maximising fitness."The unequal advances of leaf unfolding and flowering may alter trees' partitioning of resources between growth and reproduction and could leave flowers or leaves vulnerable to late spring frost damage if they appear too early" said Dr Jian-Guo Huang, the corresponding author of the study. "This could have impacts on tree species health and further affect ecosystem structure and function."Species that produce flowers before leaves, like ash, could suffer losses in seed production if flowers were damaged by late spring frost. For species that produce leaves before flowers, like horse chestnut, late spring frost damage to leaves could reduce growth and carbon uptake.Dr Qianqian Ma, lead author of the study said "The timing of phenological events is very sensitive to environmental factors, with temperature being particularly important in temperate plants. The changes in phenology we observed in our study may affect both growth and reproductive development in tree species and ultimately affect the ecosystem, nutrient cycles and carbon storage."Tree species have evolved an optimal timing for growth and reproduction based on historic climate conditions. Changes to flowering times could disrupt interactions with pollinators, impacting the survival of both species with knock-on consequences for the ecosystem. Changes to when trees are able to grow in the year can have further consequences to their survival and carbon uptake.The triggering of these phenological events is closely linked to temperature changes in the seasons. "Plants often require an exposure to chilling temperatures during winter as a cue for rest before the bursting of leaf buds or flowering can be triggered by a sufficient exposure to warmer temperatures in spring." explained Dr Qianqian Ma.For each tree species, leaf unfolding and flowering have evolved to occur in a predetermined order. Although leaf unfolding occurs first in most species, those pollinated by wind, like alder and ash, flower first so that leaves don't inhibit pollen dispersal.To collect the data on the four tree species, the researchers used the Pan European Phenology (PEP) network. This database contains annul observations of the date when leaves first unfold (or separate for evergreens) and the date when flowers first emerge for tree species across Europe. With this data the authors calculated the time intervals between first leaf date and first flower date between 1950 -- 2013 and assessed this with corresponding temperature data.Dr Qianqian Ma said: "Using long-term phenological records in Europe, we examined simultaneously the responses of both leaf unfolding and flowering of four common temperate tree species: ash, alder, horse chestnut and scots pine to climate warming."These trees were chosen to give a mix of deciduous and evergreen trees with different orders of leaf unfolding and flowering.Ideally more species would have been included in the study, but the researchers could only look at tree species with data on first leaf, first flower date and temperature. Only four tree species had sufficient data records over long enough time periods and large enough geographic areas.Dr Jian-Guo Huang said: "Further studies that simultaneously monitor the timing of phenological events and the allocation of resources within plants are needed to better evaluate the consequences of altered phenology under climate warming." | Climate | 2,020 |
December 18, 2020 | https://www.sciencedaily.com/releases/2020/12/201218165109.htm | More than half of Hudson River tidal marshes were created accidentally by humans | In a new study of tidal marsh resilience to sea level rise, geologist and first author Brian Yellen at the University of Massachusetts Amherst and colleagues observed that Hudson River Estuary marshes are growing upward at a rate two to three times faster than sea level rise, "suggesting that they should be resilient to accelerated sea level rise in the future," he says. | Writing in "In one case, historical aerial photos document this transition occurring in less than 18 years, offering a timeframe for marsh development," they point out. Yellen's co-authors are colleagues Jonathan Woodruff, Caroline Ladlow and undergraduate Waverly Lau at UMass Amherst, plus Sarah Fernald at New York's department of environmental conservation and David K. Ralston of Woods Hole Oceanographic Institution.Yellen notes that for this "very collaborative" study, the researchers took advantage of "an experiment that has already happened over decades or centuries. Many of these accidental tidal marshes worked; they protect the shoreline and provide one of the richest ecosystems in terms of direct ecological and human benefits."Further, marshes are "really useful," he adds -- as a first line of defense against coastal flooding, essential habitat for juvenile commercial fish species, they store huge amounts of carbon that mitigates climate change, they provide habitat for migratory birds, filter nutrients coming off the land "and they're beautiful."Yellen and colleagues write that these tidal wetlands "currently trap roughly 6% of the Hudson River's sediment load. Results indicate that when sediment is readily available, freshwater tidal wetlands can develop relatively rapidly in sheltered settings. The study sites serve as useful examples to help guide future tidal marsh creation and restoration efforts."Their research involved seven sites spanning more than 100 miles of the Hudson Estuary, "from Wall Street up to Albany," Yellen says. The bays where tidal marshes developed started out six to seven feet deep and have steadily grown vertically. "One concern for marshes globally is that they will be drowned by rising sea level, but this case study shows how marshes can be created and it gave us some timing benchmarks for what is considered a tricky ecosystem restoration," he adds.The researchers used two main methods to investigate the river's history and resilience in the face of sea level rise -- sediment cores that shed light on how fast sediment accumulated and historical maps, charts and aerial photos to determine how the sites have changed over time. Yellen summarizes, "As long as there is space for sediment to accumulate, new marshes can develop. There is a community of land trusts up and down the river who are planning now for future sea level rise and considering where new marshes can form. This research will help them and state agencies guide land acquisition and land conservation strategies adjacent to the river to 2100 and beyond."The research, part of the Dams and Sediment in the Hudson (DaSH) project, was supported by a grant to Ralston from NOAA's National Estuarine Research Reserve Collaborative, plus the U.S. Geological Survey and the Department of Interior Northeast Climate Adaptation Science Center at UMass Amherst.Also, Lau received a Polgar Fellowship from the Hudson River Foundation for her senior thesis project. She took the lead on one of the sites and made a short film about tidal marshes around the world and the Hudson River marsh near her home in Queens. | Climate | 2,020 |
December 18, 2020 | https://www.sciencedaily.com/releases/2020/12/201218165101.htm | Identifying where to reforest after wildfire | In the aftermath of megafires that devastated forests of the western United States, attention turns to whether forests will regenerate on their own or not. Forest managers can now look to a newly enhanced, predictive mapping tool to learn where forests are likely to regenerate on their own and where replanting efforts may be beneficial. | The tool is described in a study published in the journal "Huge fires are converting forested areas to landscapes devoid of living trees," said lead author Joseph Stewart, a postdoctoral researcher at UC Davis and with USGS. "Managers need timely and accurate information on where reforestation efforts are needed most."The tool, also known as the Post-fire Spatial Conifer Regeneration Prediction Tool (POSCRPT), helps forest managers identify within weeks after a fire where sufficient natural tree regeneration is likely and where artificial planting of seedlings may be necessary to restore the most vulnerable areas of the forest.Conifers, or plants with cones such as pine trees, dominate many forests in western North America. The study found that conifers are less likely to regenerate after fires when seedlings face drier climate conditions, especially in low-elevation forests that already experience frequent drought stress. Overall, fewer conifers are expected to grow in California's lower elevations following wildfire due to climate and drought conditions."We found that when forest fires are followed by drought, tree seedlings have a harder time, and the forest is less likely to come back," said Stewart.A UC Davis team collected post-fire recovery data from more than 1,200 study plots in 19 wildfires that burned between 2004 and 2012, as well as 18 years of forest seed production data. Ecologists at USGS collected and identified over 170,000 seeds from hundreds of seed traps. The scientists combined these data with multispectral satellite imagery, forest structure maps, climate and other environmental data to create spatial models of seed availability and regeneration probability for different groups of conifers, including pines and firs.Forest managers have used a prototype of the tool in recent years to better understand where to focus regeneration efforts. The new upgrade incorporates information on post-fire climate and seed production and includes an easy-to-use web interface expected to increase the tool's accuracy and use."This work is a great example of how multiple partners can come together to solve major resource management problems that are arising from California's climate and fire trends," said co-author Hugh Safford, regional ecologist for the USDA Forest Service's Pacific Southwest Region and a member of the research faculty at UC Davis.The study was funded by the USGS' Southwest Climate Adaptation Science Center, Ecosystems Mission Area and Land Change Science Program. | Climate | 2,020 |
December 18, 2020 | https://www.sciencedaily.com/releases/2020/12/201218131920.htm | NYS can achieve 2050 carbon goals with Earth’s help | By delving into scientific, technological, environmental and economic data, Cornell University engineering researchers examined whether New York could achieve a statewide carbon-free economy by 2050. Their finding: Yes, New York can reach this goal -- and do it with five years to spare. | Fengqi You, professor in energy systems engineering and Ning Zhao, a doctoral student in the Process-Energy-Environmental Systems Engineering (PEESE) lab, examined a variety of carbon-neutral energy systems and decarbonization methods after the state passed the Climate Leadership and Community Protection Act (CLCPA) in July 2019. Their new paper, "Can Renewable Generation, Energy Storage and Energy Efficient Technologies Enable Carbon Neutral Energy Transition?" was recently published in "Now we have a 2050 'net zero' target," You said. "As New Yorkers, we can commit to making the needed changes on renewable energy transition for electricity and space heating. The law's goals are very feasible from economic and technological perspectives."Among their research highlights:To motivate public utility companies and New Yorkers to make the needed changes, You and Zhao suggest partnering a carbon tax with the green ideas, so that New York will enjoy a faster trajectory to force out fossil energy. | Climate | 2,020 |
December 18, 2020 | https://www.sciencedaily.com/releases/2020/12/201218131902.htm | Land ecosystems are becoming less efficient at absorbing CO2 | Land ecosystems currently play a key role in mitigating climate change. The more carbon dioxide (CO | Because COFor a new study published Dec. 10 in "In this study, by analyzing the best available long-term data from remote sensing and state-of-the-art land-surface models, we have found that since 1982, the global average CFE has decreased steadily from 21 percent to 12 percent per 100 ppm of COWithout this feedback between photosynthesis and elevated atmospheric COFor instance, while an abundance of CO"According to our data, what appears to be happening is that there's both a moisture limitation as well as a nutrient limitation coming into play," Poulter said. "In the tropics, there's often just not enough nitrogen or phosphorus, to sustain photosynthesis, and in the high-latitude temperate and boreal regions, soil moisture is now more limiting than air temperature because of recent warming."In effect, climate change is weakening plants' ability to mitigate further climate change over large areas of the planet.The international science team found that when remote-sensing observations were taken into account - including vegetation index data from NASA's Advanced Very High Resolution Radiometer (AVHRR) and the Moderate Resolution Imaging Spectroradiometer (MODIS) instruments - the decline in CFE is more substantial than current land-surface models have shown. Poulter says this is because modelers have struggled to account for nutrient feedbacks and soil moisture limitations - due, in part, to a lack of global observations of them."By combining decades of remote sensing data like we have done here, we're able to see these limitations on plant growth. As such, the study shows a clear way forward for model development, especially with new remote sensing observations of vegetation traits expected in coming years," he said. "These observations will help advance models to incorporate ecosystem processes, climate and COThe results of the study also highlight the importance of the role of ecosystems in the global carbon cycle. According to Poulter, going forward, the decreasing carbon-uptake efficiency of land ecosystems means we may see the amount of CO"What this means is that to avoid 1.5 or 2°C warming and the associated climate impacts, we need to adjust the remaining carbon budget to account for the weakening of the plant CO | Climate | 2,020 |
December 18, 2020 | https://www.sciencedaily.com/releases/2020/12/201218131854.htm | Devastating skin disease covering up to 70% of a dolphin's body tied to climate change | Scientists at The Marine Mammal Center in Sausalito, CA -- the largest marine mammal hospital in the world -- and international colleagues have identified a novel skin disease in dolphins that is linked to climate change. The study is a groundbreaking discovery, as it is the first time since the disease first appeared in 2005 that scientists have been able to link a cause to the condition that affects coastal dolphin communities worldwide. Due to the decreased water salinity brought upon by climate change, the dolphins develop patchy and raised skin lesions across their bodies -- sometimes covering upwards of 70 percent of their skin. | The international study, which can be found here, was co-authored by three internationally respected scientists, from California and Australia:The study, published in This study comes on the heels of significant outbreaks in Louisiana, Mississippi, Alabama, Florida and Texas and Australia in recent years. In all of these locations, a sudden and drastic decrease in salinity in the waters was the common factor. Coastal dolphins are accustomed to seasonal changes in salinity levels in their marine habitat, but they do not live in freshwater. The increasing severity and frequency of storm events like hurricanes and cyclones, particularly if they are preceded by drought conditions, are dumping unusual volumes of rain that turn coastal waters to freshwater. Freshwater conditions can persist for months, particularly after intense storms such as hurricanes Harvey and Katrina. With the increasing climate temperatures, climate scientists have predicted extreme storms like these will occur more frequently and, consequently, will result in more frequent and severe disease outbreaks in dolphins."This devastating skin disease has been killing dolphins since Hurricane Katrina, and we're pleased to finally define the problem," said Duignan. "With a record hurricane season in the Gulf of Mexico this year and more intense storm systems worldwide due to climate change, we can absolutely expect to see more of these devastating outbreaks killing dolphins."The study has major implications for the current outbreak in Australia, which is impacting the rare and threatened Burrunan dolphin in southeast Australia, and could provide professionals with the information needed to diagnose and treat affected animals. Currently, the long-term outlook for dolphins affected with the skin disease is poor. This is especially true for the animals suffering from prolonged exposure to freshwater.The deadly skin disease was first noted by researchers on approximately 40 bottlenose dolphins near New Orleans after Hurricane Katrina in 2005."As warming ocean temperatures impact marine mammals globally, the findings in this paper will allow better mitigation of the factors that lead disease outbreaks for coastal dolphin communities that are already under threat from habitat loss and degradation," said Duignan. "This study helps shed light on an ever-growing concern, and we hope it is the first step in mitigating the deadly disease and marshalling the ocean community to further fight climate change." | Climate | 2,020 |
December 18, 2020 | https://www.sciencedaily.com/releases/2020/12/201218131850.htm | Roadmap to renewables unites climate and sustainability goals | While the pressures of climate change bring a sense of urgency to renewable energy development, a new study serves as a roadmap toward uniting the goals of a low-carbon future with that of ecological sustainability and conservation. | The study, published in the journal "Renewables aren't always sustainable, but they can be if we think proactively," said co-leading author Sarah Jordaan, an assistant professor at John Hopkins University's School of Advanced International Studies. "There is a huge misalignment between United Nations Sustainable Development Goals and climate goals. This is a call to action for leaders to come together to address it."To develop the roadmap, the authors assessed public and private investments in renewable energy and analyzed the tradeoffs and synergies of clean energy. They also identified research themes drawn from a two-day workshop held by the Electric Power Research Institute in 2019 with 58 leading experts in the fields of renewable energy and sustainability from across academia, industry, government sectors.Among the key research priorities identified for sustainable solar and wind developments include site selection and understanding interactions with wildlife.For example, Florida's longleaf pine forests have, for centuries, helped store carbon, protect water quality and provide wildlife habitat. Now, only a fraction of the historical range of longleaf pine forests in the state remain. Yet a sliver of that remaining sliver is slated to be replaced by a solar installation.Meanwhile, in the same state and just a few miles away, waterbirds squawk, preen their feathers, and hunt for food atop a floating array of solar panels -- a "floatovoltaic" installation. Here, both wildlife and greenhouse-gas-reduction goals appear to coexist gracefully."We can't pursue climate change mitigation blindly," said co-leading author Rebecca. R. Hernandez, a UC Davis assistant professor and founding director of the Wild Energy Initiative in the John Muir Institute of the Environment. "We must consider the impacts of renewables on the few ecosystems we have left."Other key considerations and priorities the scientists identified were public acceptance of clean energy projects and the study of end-of-life management for wind and solar. For instance, the composites in wind blades are not recyclable, and solar panels contribute to a growing electronic waste problem.The authors said the work highlights how the field of sustainable renewable energy is in its infancy, with many of the questions and solutions unclear. The roadmap, they emphasize, is a living document, designed to change as the field matures."We're pushing forward into maturation something that is really just being born," Hernandez said of renewable energy. "Across its sectors, everyone is trying to figure things out as quickly as possible. This roadmap points to the fact that we all need to get organized and work together to share knowledge, innovation and results."Jordaan said while the roadmap highlights problems, they are solvable."We need to research the things we don't know, implement solutions we do know, and develop technology as needed and ensure accountability," she said. | Climate | 2,020 |
December 18, 2020 | https://www.sciencedaily.com/releases/2020/12/201218131844.htm | Water limitations in the tropics offset carbon uptake from Arctic greening | More plants and longer growing seasons in the northern latitudes have converted parts of Alaska, Canada and Siberia to deeper shades of green. Some studies translate this Arctic greening to a greater global carbon uptake. But new research shows that as Earth's climate is changing, increased carbon absorption by plants in the Arctic is being offset by a corresponding decline in the tropics. | "This is a new look at where we can expect carbon uptake to go in the future," said scientist Rolf Reichle with the Global Modeling and Assimilation Office (GMAO) at NASA's Goddard Space Flight Center in Greenbelt, Maryland.Reichle is one of the authors of a study, published Dec. 17 in Together, these provide a more accurate estimate of global "primary productivity" -- a measure of how well plants convert carbon dioxide and sunlight to energy and oxygen via photosynthesis, for the time span between 1982 to 2016.Plant productivity in the frigid Arctic landscape is limited by the lengthy periods of cold. As temperatures warm, the plants in these regions have been able to grow more densely and extend their growing season, leading to an overall increase in photosynthetic activity, and subsequently greater carbon absorption in the region over the 35-year time span.However, buildup of atmospheric carbon concentrations has had several other rippling effects. Notably, as carbon has increased, global temperatures have risen, and the atmosphere in the tropics (where plant productivity is limited by the availability of water) has become drier. Recent increases in drought and tree mortality in the Amazon rainforest are one example of this, and productivity and carbon absorption over land near the equator have gone down over the same time period as Arctic greening has occurred, canceling out any net effect on global productivity.Previous model estimates suggested that the increasing productivity of plants in the Arctic could partially compensate for human activities which release atmospheric carbon, like the burning of fossil fuels. But these estimates relied on models that calculate plant productivity based on the assumption that they photosynthesize (convert carbon and light) at a given efficiency rate.In reality, many factors can affect plants' productivity. Including satellite records like those from AVHRR provide scientists with consistent measurments of the global photosynthetic plant cover, and can help account for variable events such as pest outbreaks and deforestation that previous models do not capture. These can impact the global vegetation cover and productivity."There have been other studies that focused on plant productivity at global scales," said Nima Madani from NASA's Jet Propulsion Laboratory, (JPL) Pasadena, California, and lead author of the study, which also includes scientists from the University of Montana. "But we used an improved remote sensing model to have a better insight into changes in ecosystem productivity." This model uses an enhanced light use efficiency algorithm, which combines multiple satellites' observations of photosynthetic plant cover and variables such as surface meteorology."The satellite observations are critical especially in regions where our field observations are limited, and that's the beauty of the satellites," Madani said. "That's why we are trying to use satellite remote sensing data as much as possible in our work."It was only recently that the satellite records began to show these emerging trends in shifting productivity. According to Reichle, "The modelling and the observations together, what we call data assimilation, is what really is needed." The satellite observations train the models, while the models can help depict Earth system connections such as the opposing productivity trends observed in the Arctic and tropics.The satellite data also revealed that water limitations and decline in productivity are not confined to the tropics. Recent observations show that the Arctic's greening trend is weakening, with some regions already experiencing browning."I don't expect that we have to wait another 35 years to see water limitations becoming a factor in the Arctic as well," said Reichle. We can expect that the increasing air temperatures will reduce the carbon uptake capacity in the Arctic and boreal biomes in the future. Madani says Arctic boreal zones in the high latitudes that once contained ecosystems constrained by temperature are now evolving into zones limited by water availability like the tropics.These ongoing shifts in productivity patterns across the globe could affect numerous plants and animals, altering entire ecosystems. That can impact food sources and habitats for various species, including endangered wildlife, and human populations. | Climate | 2,020 |
December 18, 2020 | https://www.sciencedaily.com/releases/2020/12/201218112538.htm | Ice sheet uncertainties could mean sea level will rise more than predicted | Sea level could rise higher than current estimates by 2100 if climate change is unchallenged, according to a new assessment. | Its authors say understanding the way strong global heating affects polar ice sheets will be crucial to projecting sea level rise over the next century. However, uncertainties remain and current knowledge about ice sheets suggests sea-level rise under continued strong warming could be higher than the Intergovernmental Panel on Climate Change (IPCC) 'likely' range by 2100.The authors of the study, published today in the journal Lead author Professor Martin Siegert, from the Grantham Institute -- Climate Change and Environment at Imperial College London, said: "Greenhouse gas emissions are still on the rise, and strong heating, of more than 4°C by 2100, is well within the realm of the possible if emissions continue unabated."Currently, hundreds of millions of people live in regions susceptible to coastal flooding, and the likelihood of even worse flooding will significantly increase with severe sea-level rise. The sea-level rise we have already faced has been somewhat mitigated by flood barriers and other measures, but we are unprepared for higher rates of rise that could overwhelm these measures. If we don't do more to avert dangerous global heating, we may reach a point where we can no longer protect people."The team reviewed current models of the effect of warming on ice sheets that the IPCC's 2019 report on sea-level rise relies on. For the strong heating scenario of more than 4°C of temperature rise by 2100, the report gave a 'likely' range for sea-level rise of between 0.61 and 1.10 metres above 1950 levels.However, the team's analysis showed that ice sheet models do not include sufficient detail on key processes that may lead to significant mass loss under strong warming, meaning sea level rise above the IPCC's likely range is far more possible than below it.Co-author John Englander, President and Founder of the Rising Seas Institute, said: "Sea-level rise will be one of the most challenging issues faced by society in the coming decades. We need to recognize that we cannot stand by and wait for clarity about actual sea-level rise to begin planning for it."Waiting for better confidence in predictions is not a reason to delay building a margin of safety, for example into building codes and zoning, recognising the inevitability of sea-level rise and its catastrophic implications."There are two main ways sea level can rise substantially at a global level. Throughout the twentieth century, rise has been dominated by thermal expansion -- added heat driving water molecules apart, expanding the volume of the ocean water. In the twenty-first century, however, the second mechanism has become dominant: the addition of water from melting ice sheets and glaciers.While sea-level rise due to thermal expansion can be predicted using relatively simple relationships between the temperature and the expansion, ice sheets and glaciers respond to rising temperatures in complex and interconnected ways that make prediction more fraught.Researchers looking ahead to the next century of climate change and its increasing impact on human society, nature and the environment often look back at previous episodes of natural climate change for clues as to how various earth systems will react.At the end of the last ice age, there is evidence that ice sheets responded to warming by rapidly losing mass at rates that at times were higher than currently observed, leading to several metres of sea-level rise per century.The team say this means current projections of sea-level rise may be underestimates, as the ice sheets may lose mass faster over the coming century than our current models predict.To improve models and predictions, the authors identify key areas of research that are needed to fill in our gaps in knowledge. These include better mapping of the ground beneath glaciers and ice sheets, collection of data at the margin where glaciers meet the ocean, and improved coupling of models of the atmosphere, oceans, and ice sheets.While the network of existing observations of ice sheet dynamics already gives scientists a very strong warning signal and causes for concern, the authors say these improvements could lead to a next-generation 'early warning system' focused on signals of rapid change in sea level, such as increases in ocean water temperature along the margins of ice sheets.Professor Siegert said: "We already have a good start on an early warning system for dangerous sea-level rise, with satellites, airborne platforms, robotic devices, field investigators, and expert knowledge. While this network is growing and getting stronger, it has major weaknesses at ice-sheet boundaries that require urgent action. We need to develop an array of robotic devices in key parts of Antarctica and Greenland that are most vulnerable and capable of rapid sea-level rise in the future." | Climate | 2,020 |
December 18, 2020 | https://www.sciencedaily.com/releases/2020/12/201218084113.htm | Fire-resistant tropical forest on brink of disappearance | A new study led by researchers in the Geography Department at Swansea University reveals the extreme scale of loss and fragmentation of tropical forests, which once covered much of the Indonesian islands of Sumatra and Kalimantan. | The study also reveals that only 10% of the forest that is left remains fire-resistant. The researchers warn that protecting this is crucial for preventing catastrophic fire.Tropical deforestation exacerbates recurrent peatland fire events in this region. These release globally significant greenhouse gas emissions and produce toxic haze events across South East Asia.An area of tropical forest and peatland larger than the Netherlands has burned in Indonesia in the past five years, according to Greenpeace.Yet the study shows that contiguous tracts of undisturbed forests are not susceptible to burning even under current drought conditions.Dr Tadas Nikonovas of Swansea University, lead author of the research, explained:"Undisturbed tropical rainforests are naturally resistant to fire due to the humid and cool micro-climate they maintain, effectively acting as a fire barrier. Contrary to the widely-held perception that worsening droughts are threatening the remaining rainforests, tropical forests in Indonesia become susceptible to fire only after human disturbance."However, the study also reveals that currently only a small fraction (~10%) of the remaining total tropical forest cover remains fire-resistant. The rest (~90%) has been severely fragmented or degraded and therefore is no longer able to maintain a fire-resistant microclimate.Importantly, fire-resistant forests now cover only 3% of the region's peatlands, leaving large amounts of climate-critical carbon vulnerable to burning.The authors emphasize that the preventative role tropical forests play against fire is yet another important reason for the preservation and regeneration of the few remaining contiguous tracts of forests.Dr Allan Spessa of Swansea University, the project leader, added:"Protecting tropical forest is critical not only for biodiversity and carbon storage but also for preventing future catastrophic fire episodes. This is true for Indonesia, as well as for tropical forest in Africa and South America."The research was published in a Nature group journal This study is part of Swansea University-based Towards Fire Early Warning System for Indonesia (ToFEWSI) project. | Climate | 2,020 |
December 17, 2020 | https://www.sciencedaily.com/releases/2020/12/201217154051.htm | How climate change is disrupting ecosystems | The world is getting warmer and warmer -- and many organisms native to lower latitudes or elevations are moving higher. | However, novel organisms moving into a new habitat could disturb the ecological balance which has been established over a long period. Plants and herbivores are characterised by long-term co-evolution, shaping both their geographic distribution and the characteristics that they display in their occupied sites.At higher elevations, this is seen in insect herbivores being generally less abundant and plants in turn being less well defended against herbivores, as a result of lower energy and shorter growing seasons. In contrast, low-elevation plant species defend themselves against more abundant and diverse herbivores, whether by means of spikes, thorns or hair, or by toxic substances. Climate change could disturb this ecological organisation.In an experiment, researchers from ETH Zurich, the Swiss Federal Institute for Forest, Snow and Landscape Research (WSL) and the University of Neuchâtel investigated what could happen if herbivores -- in this case various grasshoppers from middle elevations -- settled in alpine meadows at higher elevations and encountered new plant communities there. The study has just been published in the journal The researchers translocated various grasshopper species from medium altitudes (1,400 metres above sea level) to three alpine grassland sites at elevations of 1,800, 2,070 and 2,270 metres above sea level, where the ecologists placed the grasshoppers in cages. The local grasshoppers had previously been removed from the experimental areas. The experiment was carried out in the Anzeindaz region in the Vaud Alps, Switzerland.In their study, the researchers measured things like how the biomass, structure and composition of the alpine plant communities changed under the influence of the herbivorous insects. The researchers also investigated whether some plant species were more susceptible to herbivory, for instance plants with tougher leaves, or those containing more silica or other constituents such as phenols or tannins.The ecologists discovered that the grasshoppers' feeding behaviour had a clear influence on the vegetation structure and composition of the alpine flora. Alpine communities display clear structure in the organisation of the canopy, with plants with tough leaves at the top, and more shade-tolerant plants with softer leaves at the bottom. But this natural organisation was disturbed, because the translocated grasshoppers preferred to feed on taller and tough alpine plants, which exhibited functional characteristics such as leaf structure, nutrient content, chemical defence, or growth form similar to those of their previous, lower-elevation food plants. As a result, the insects reduced the biomass of dominant tough alpine plants, which in turn favoured the growth of small-stature plant species that herbivores avoid. The overall plant diversity thus increased in the short term."Immigrant herbivores consume specific plants in their new location and this changes and reorganises the competitive interaction between those alpine plant species," says the study's first author, Patrice Descombes. Global warming, for example, could disrupt the ecological balance because mobile animals, including many herbivorous insects, can expand their habitat to higher elevations more rapidly than sedentary plants. Herbivorous insects from lower altitudes could therefore have an easy time in alpine habitats with resident plants that are insufficiently or not at all prepared to defend themselves against those new herbivores. This could change the current structure and functioning of alpine plant communities as a whole. Climate change would thus have an indirect impact on ecosystems, in addition to the direct consequences of rising temperatures.For Loïc Pellisier, Professor of Landscape Ecology at ETH Zurich and WSL, this indirect effect of climate change on ecosystems is one of the most important things to emerge from the study: "Climate impact research has largely investigated the direct effects of temperature on ecosystems, but these novel interactions that arise between species moving into new habitats could generate important structural modifications. They are important drivers of changed ecosystems in an increasingly warm climate."With their results, the researchers also want to improve models that have so far only inadequately integrated such processes. They also hope that this will improve the prognosis of how climate change will influence the functioning of ecosystems and the services they provide. | Climate | 2,020 |
December 17, 2020 | https://www.sciencedaily.com/releases/2020/12/201217154044.htm | Oceans without oxygen | With no dissolved oxygen to sustain animals or plants, ocean anoxic zones are areas where only microbes suited to the environment can live. | "You don't get big fish," said UC Santa Barbara biogeochemist Morgan Raven. "You don't even get charismatic zooplankton." But although anoxic oceans may seem alien to organisms like ourselves that breathe oxygen, they're full of life, she said.These strange ecosystems are expanding, thanks to climate change -- a development that is of concern for fisheries and anyone who relies on oxygen-rich oceans. But what piques Raven's interest is the changing chemistry of the oceans -- the Earth's largest carbon sink -- and how it could move carbon from the atmosphere to long-term reservoirs like rocks."What happens to our carbon cycle as we get these large areas of the ocean that are oxygen-free?" she said. This question was central to research conducted by Raven and colleagues Rick Keil (University of Washington) and Samuel Webb (Stanford Linear Accelerator Laboratory) in a paper published in the journal In oxygen-rich oceans, carbon is moved around largely by food web processes that begin with carbon dioxide-fixing phytoplankton that photosynthesize at the water's surface."Most of the time they just get eaten by zooplankton," Raven said. But if they aren't eaten by larger animals, they head to the depths where they respire carbon dioxide and excrete organic carbon."It's like a spinning wheel -- COIn the absence of zooplankton and fish, however, more of the sinking organic carbon can survive and be deposited at depth, she said. In fact, sediments under these anoxic zones generally have more organic carbon deposits than their oxygen-rich counterparts. But, according to the researchers, we lack a "full mechanistic understanding" of how this occurs."It's been a bit of a mystery," Raven said.The team did have a clue in the form of a hypothesis formed about a decade ago by University of Southern Denmark geologist Don Canfield and colleagues."They put out this idea that maybe inside of these zones, microbes are still eating organic carbon, but respiring sulfate," Raven said. Called "cryptic sulfur cycling," the idea was somewhat difficult to accept largely because the products of this microbial sulfate reduction (MSR) were difficult to detect, and because other compounds in the area, such as nitrates, were more energetically favorable to metabolize.However, according to the study, "there is emerging molecular and geochemical evidence that suggests MSR may occur in (oxygen-deficient zones) despite plentiful dissolved nitrate."The researchers tested whether this enigmatic process might be hiding inside of large (>1mm), fast-sinking organic particles by collecting particles from the Eastern Tropical North Pacific oxygen-deficient zone, roughly located off the northwestern coast of Mexico."It really is just this polymeric, sticky stuff," Raven said of the aggregations of mostly dead phytoplankton, fecal matter, other small organisms and bits of sand and clay that get glued together in a "fluffy" matrix. Collection of these particles is itself an accomplishment for researchers combing the vast oceans for relatively small, diffuse particles."My colleagues from the University of Washington had this collection device that was really the thing that made it possible to do this," she said. The collected particles were sent to the Stanford Synchotron Radiation Lightsource for analysis.Results of the analysis, such as evidence of the production of organic sulfur within the samples, demonstrate what Raven calls a "pickling" of the dead phytoplankton, as they sink through the anoxic area."Phytoplankton grow in the surface ocean, but due to gravity, they sink," she said. As they fall through the anoxic region, these organic aggregates undergo sulfurization, which has the effect of shielding the carbon at their core from enzymes or other substances that would otherwise wear them away."Even when it gets to the sediment, bacteria there can't eat these organic particles," noted Raven. And just like the pickles we know and love, the preservation process makes the organic particle resistant to bacteria, she said, which could explain why more organic carbon is found in the sediments below anoxic ocean zones.Sulfurization of organic carbon particles in anoxic ocean zones, while newly confirmed in modern-day oceans, is actually an ancient process, Raven explained."It's the same process that can also make petroleum," she said, pointing out that where oilbeds are found, so, too, is sulfur. This process may have been widespread during the Cretaceous period (145.5 to 65.5 million years ago), when the Earth was consistently tropical and the ocean was subject to geologic and mass extinction events that resulted in the burial of massive amounts of carbon, and anoxic waters throughout the Atlantic."What we didn't know is whether this was also going on in these less extreme modern environments," Raven said.What remains to be seen is how these growing oxygen depleted zones will interact with climate change."Potentially as these zones expand, there could be a negative feedback -- more CO | Climate | 2,020 |
December 17, 2020 | https://www.sciencedaily.com/releases/2020/12/201217145231.htm | Taking the chill off icy build-up on planes and wind turbines | New UBC Okanagan research is changing the way aircraft and wind turbine operators are addressing the risks related to ice build-up. | In a follow-up study from one released previously this year, Assistant Professor Mohammad Zarifi and his team at UBCO's Okanagan MicroElectronics and Gigahertz Applications (OMEGA) Lab, have broadened the scope and functionality of their ice sensors."We received a great deal of interest from the aviation and renewable energy industries stemming from our initial findings which pushed us to expand the boundaries of the sensor's responsiveness and accuracy," explains Zarifi.Ice build-up on aircraft and wind turbines can impact the safety and efficiency of their systems, he notes.In this latest research, the researchers focused on improving the real-time response of the sensors to determining frost and ice build-up. The sensors can identify in real-time these accumulations while calculating the rate of melting. This is crucial data for aviation, for keeping flights on time, and renewable energy applications, says Zarifi."Power generation output of wind turbines diminishes as a result of ice accumulations," he adds. "So, the industry sees great promise in sensing and de-icing solutions that can mitigate those reductions in efficiency."Zarifi says the patented sensor, which includes a protective layer, is now being tested by the aviation industry through a rigorous approval process. This needs to be done before it can become a permanent fixture on aircraft. He notes that recently announced funding from the Department of National Defense will enable his team to continue to improve the sensor's capabilities.Zarifi is also collaborating with a number of wind turbine companies to adapt the sensors into wind farms. The wind farm application is a slightly more straightforward proposition, he says, because the sensors can be mounted at the same altitude of the blades without having to be mounted to the blades -- this removes certain calculation variables that are related to motion.In the midst of these breakthroughs, the researchers have uncovered another first when it comes to ice sensing technology. Their latest innovation can sense salty ice, which freezes at colder temperatures. Interest in understanding and monitoring saltwater ice formation is increasing due to issues caused by saltwater ice on oil rigs and marine infrastructure. Zarifi and his team at OMEGA Lab are working towards the introduction of microwave/radar-based technology to address this challenge.By incorporating an antenna into the sensor, the results can be shared in real-time with the operator in order to address the build-up.Zarifi says his team is as excited as the industry partners to see how their microwave and antenna, which have proven to be durable and robust, can be modified for various applications including ice and moisture sensing.The research was funded by a National Sciences and Engineering Research Council of Canada Discovery Grant, Mitacs Accelerate Grant, and grants from the Canada Foundation for Innovation, and the Canadian Department of National Defense. It was published in the journal | Climate | 2,020 |
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