Goodbye to Cold Nights
Farm in Candelario, Spain (G.Chris Clark)
Given the impact of climatic extremes on agriculture and health in Spain, researchers at the University of Salamanca (USAL) have analysed the two factors most representative of these thermal extremes between 1950 and 2006 – warm days and cold nights. The results for mainland Spain show an increase in the number of warm days greater than that for the rest of the planet and a reduction in the number of cold nights.
Few studies to date have focused on climatic extremes and the changes occurring in maximum and minimum temperatures and in warm day and cold night variables. Until now, most research studies had analysed average temperature changes on a global scale. These results indicated an increase “most probably” caused by human factors.
The new study, published in the journal Climatic Change, has made it possible to analyse the causes of the variations in climatic extremes from a physical point of view, in other words “which changes are taking place in the air masses reaching the Iberian Peninsula, as well as sea temperature”, as Concepción Rodríguez, lead author of the study and a researcher at the General and Atmospheric Physics Department at the USAL, tells SINC. (more…)
International Penguin Conference in Boston
Penguins over past decade have soared in global popularity, yet many of their populations have crashed during the same time. This week in Boston, penguin biologists from around the world will gather for their quadrennial meeting, and one of the hot topics will be the possible effects of climate change on declining penguin populations.
All penguin species are found only south of the equator, and over the twenty year history of International Penguin Conferences, all of them had been held in the Southern Hemisphere, until now. From August 29 until September 5, the New England Aquarium of Boston will be creating its own colony of the world’s leading penguin researchers, biologists and policy makers. More than 180 penguin enthusiasts from Australia, Asia Africa, Europe and the Americas will present ongoing research, identify current and emerging conservation issues and create action plans.
Of the eighteen penguin species, twelve are classified internationally as threatened or endangered, and many are facing extinction. Global climate change, competition for food from commercial fishing, habitat loss from coastal development and oil spills sre among the myriad of threats that imperil these beloved birds. (more…)
Climate Change Implicated in Decline of Horseshoe Crabs
Horseshoe crabs congregate annually at Delaware Bay. (Greg Breese, , U.S. Fish and Wildlife Service )
A distinct decline in horseshoe crab numbers has occurred that parallels climate change associated with the end of the last Ice Age, according to a study that used genomics to assess historical trends in population sizes.
The new research also indicates that horseshoe crabs numbers may continue to decline in the future because of predicted climate change, said Tim King, a scientist with the U.S. Geological Survey and a lead author on the new study published in Molecular Ecology.
While the current decline in horseshoe crabs is attributed in great part to overharvest for fishing bait and for the pharmaceutical industry, the new research indicates that climate change also appears to have historically played a role in altering the numbers of successfully reproducing horseshoe crabs. More importantly, said King, predicted future climate change, with its accompanying sea-level rise and water temperature fluctuations, may well limit horseshoe crab distribution and interbreeding, resulting in distributional changes and localized and regional population declines, such as happened after the last Ice Age. (more…)
Dramatic Climate Change is Unpredictable
This is a schematic picture of the climate represented by the red ball. The climate can be located in two different states, the two valleys on each side of a hill. In the first scenario the climate is like a seesaw. If the outside influences increase or, for example, increased CO2 makes the weight heavier on the other side, the seesaw will tip forcing the climate over into the other state. The climate change would be predictable. In the second scenario, the hill is fixed and a series of small chaotic kicks from wind and weather could cause it to roll over into the other state. This climate change is unpredictable. Mathematically speaking, the first scenario is a "bifurcation" and the second scenario "noise-induced transition". (Credit: Peter Ditlevsen)
The fear that global temperature can change very quickly and cause dramatic climate changes that may have a disastrous impact on many countries and populations is great around the world. But what causes climate change and is it possible to predict future climate change? New research from the Niels Bohr Institute at the University of Copenhagen shows that it may be due to an accumulation of different chaotic influences and as a result would be difficult to predict. The results have just been published in Geophysical Research Letters.
For millions of years the Earth’s climate has alternated between about 100,000 years of ice age and approximately 10-15,000 years of a warm climate like we have today. The climate change is controlled by the Earth’s orbit in space, that is to say the Earth’s tilt and distance from the sun. But there are also other climatic shifts in the Earth’s history and what caused those?
Dramatic climate change of the past
By analysing the ice cores that are drilled through the more than three kilometer thick ice sheet in Greenland, scientists can obtain information about the temperature and climate going back around 140,000 years. (more…)
Review Finds UN Climate Body Needs Fundamental Reform
Harold T. Shapiro, president emeritus and professor of economics and public affairs at Princeton University. (Photo courtesy of Princeton University)
The process used by the Intergovernmental Panel on Climate Change to produce its periodic assessment reports has been successful overall, but IPCC needs to fundamentally reform its management structure and strengthen its procedures to handle ever larger and increasingly complex climate assessments as well as the more intense public scrutiny coming from a world grappling with how best to respond to climate change, says a new report from the InterAcademy Council (IAC), an Amsterdam-based organization of the world’s science academies.
“Operating under the public microscope the way IPCC does requires strong leadership, the continued and enthusiastic participation of distinguished scientists, an ability to adapt, and a commitment to openness if the value of these assessments to society is to be maintained,” said Harold T. Shapiro, president emeritus and professor of economics and public affairs at Princeton University in the United States and chair of the committee that wrote the report. Roseanne Diab, executive officer of the Academy of Science of South Africa and professor emeritus of environmental sciences and honorary senior research associate at the University of KwaZulu-Natal in Durban, served as vice chair of the committee, which included experts from several countries and a variety of disciplines.
The IPCC was established in 1988 by the World Meteorological Organization and the United Nations Environment Programme to inform policy decisions through periodic assessments of what is known about the physical scientific aspects of climate change, its global and regional impacts, and options for adaptation and mitigation. Representatives of 194 participating governments make up the Panel, which sets the scope of the assessments, elects the Bureau that oversees them, and approves the Summaries for Policymakers that accompany the massive assessment reports themselves, which are prepared by thousands of scientists who volunteer for three Working Groups. (more…)
Scientists Projected an Increase in Intensity and Frequency of Extreme Weather Events
As reported on the website of the World Meteorological Organization: Several diverse extreme weather events are occurring concurrently around the world, giving rise to an unprecedented loss of human life and property. They include the record heatwave and wildfires in the Russian Federation, monsoonal flooding in Pakistan, rain-induced landslides in China, and calving of a large iceberg from the Greenland ice sheet. These should be added to the extensive list of extreme weather-related events, such as droughts and fires in Australia and a record number of high-temperature days in the eastern United States of America, as well as other events that occurred earlier in the year.
The heatwave in the European part of the Russian Federation is associated with a persistent pressure ridge that appeared in June 2010. Initially, it was associated with the Azores high, but later was reinforced by a strong inflow of warm air from the Middle East. More than 20 daily temperature records were broken including the absolute maximum temperature in Moscow. The high temperatures triggered massive forest and peat fires in the European part of the country. Some villages were burned completely, with smoke and smog adversely and greatly affecting the health and well-being of tens of millions of people. (more…)
Turning Up the Temperature in the High Arctic
Al Werner on his way to the day's research site in Svalbard, Norway
Al Werner is feeling the heat this summer. Typically, that wouldn’t be a problem to alleviate; a jump in the pool or a visit to the movie theatre would cool things down. But there weren’t pools or movie theatres in the Norwegian Arctic, where Werner just finished conducting research as part of the Svalbard Research Experience for Undergraduates (REU). There were, however, glaciers–and, as the Mount Holyoke professor of geology found, they’re melting. Quickly.
“There is clear evidence of climate change here,” Werner said via email from Svalbard. “The Linne´ Glacier has been retreating since 1936 at an average rate of 20 meters per year. Since 2002, that rate has increased twofold, to nearly 40 meters per year. Now, we’re seeing the return of warm-water-loving mollusks. These results are consistent with other Arctic regions that likewise show accelerated warming in the past two decades.”
It’s an alarming trend that the REU is monitoring in the Norwegian High Arctic. The project’s ultimate goals are to monitor the area’s glacier/river/lake system, and to provide a better understanding of natural (pre-industrial) climate change there.
The Svalbard research is just one part of the much larger REU program, funded by the National Science Foundation, that aims to attract undergraduates to scientific fields by immersing them in field research experiences. In this way, Werner says, his REU project is mainly about educating and, hopefully, inspiring tomorrow’s climate change scientists. (more…)
Geo-Engineering and Sea-Level Rise Over the 21st Century
Scientific findings by international research group of scientists from England, China and Denmark just published suggest that sea level will likely be 30-70 centimetres higher by 2100 than at the start of the century even if all but the most aggressive geo-engineering schemes are undertaken to mitigate the effects of global warming and greenhouse gas emissions are stringently controlled.
“Rising sea levels caused by global warming are likely to affect around 150 million people living in low-lying coastal areas, including some of the world’s largest cities,” explained Dr Svetlana Jevrejeva of the National Oceanography Centre.
Most scientists agree that anthropogenic carbon dioxide emissions contribute greatly to global warming, and that these emissions need to be controlled if damaging future impacts such as sea-level rise are to be averted. But if we fail to do so, is there a ‘Plan B’?
Scientists have proposed ways of ‘geo-engineering’ the Earth system to tackle global warming, thereby reducing its impact on both the main contributors of sea level rise: thermal expansion of ocean water and melting of glaciers and ice sheets. Jevrejeva and her colleagues have modelled sea level over the 21st century under various geo-engineering schemes and carbon dioxide emission scenarios.
“We used 300 years of tide gauge measurements to reconstruct how sea level responded historically to changes in the amount of heat reaching the Earth from the Sun, the cooling effects of volcanic eruptions, and past human activities,” said Jevrejeva. “We then used this information to simulate sea level under geo-engineering schemes over the next 100 years.” (more…)
Carnivore Species Shrank During Global Warming Event
by Leeann Bright
Stephen Chester (left) and Jon Bloch examine the jaw of a new species of carnivorous mammal at the Florida Museum of Natural History on the University of Florida campus on Aug. 18, 2010. The hyena-like animal, Palaeonictis wingi, is described in a new UF study now available online and scheduled to be published in the December print edition of the Journal of Mammalian Evolution. The study shows the species evolved to a smaller size during a global warming event that occurred 55 million years ago. Earth’s temperature increased about 15 degrees Fahrenheit during the 200,000 year period. (Photo by: Jennifer Duerden/University of Florida)
A new University of Florida study indicates extinct carnivorous mammals shrank in size during a global warming event that occurred 55 million years ago.
The study, scheduled to appear in the December print edition of the Journal of Mammalian Evolution and now available online, describes a new species that evolved to half the size of its ancestors during this period of global warming.
The hyena-like animal, Palaeonictis wingi, evolved from the size of a bear to the size of a coyote during a 200,000-year period when Earth’s average temperature increased about 15 degrees Fahrenheit. Following this global warming event, Earth’s temperature cooled and the animal evolved to a larger size.
“We know that plant-eating mammals got smaller during the earliest Eocene when global warming occurred, possibly associated with elevated levels of carbon dioxide,” said lead author Stephen Chester, a Yale University doctoral student who began the research at UF with Jonathan Bloch, curator of vertebrate paleontology at the Florida Museum of Natural History. “Surprisingly, this study shows that the same thing happened in some carnivores, suggesting that other factors may have played a critical role in their evolution.”
Researchers discovered a nearly complete jaw from the animal in Wyoming’s Big Horn Basin in 2006 during a fossil-collecting expedition, led by Bloch, a co-author on the study. Bloch said the new findings could help scientists better understand the impact of current global warming. (more…)
Is the Ice in the Arctic Ocean Getting Thinner and Thinner?
Propeller of Polar 5, the scientific aircraft of Alfred Wegener Institute, on its flight across Svalbard. (Photo: Ralf Röchert, Alfred Wegener Institute)
The extent of the sea ice in the Arctic will reach its annual minimum in September. Forecasts indicate that it will not be as low as in 2007, the year of the smallest area covered by sea ice since satellites started recording such data. Nevertheless, sea ice physicists at the Alfred Wegener Institute are concerned about the long-term equilibrium in the Arctic Ocean.
They have indications that the mass of sea ice is dwindling because its thickness is declining. To substantiate this, they are currently measuring the ice thickness north and east of Greenland using the research aircraft Polar 5. The objective of the roughly one-week campaign is to determine the export of sea ice from the Arctic. Around a third to half of the freshwater export from the Arctic Ocean takes place in this way – a major drive factor in the global ocean current system.
The question of when the Arctic will be ice-free in the summer has been preoccupying the sea ice researchers headed by Prof. Dr. Rüdiger Gerdes from the Alfred Wegener Institute for Polar and Marine Research in the Helmholtz Association for a long time now. (more…)
Limiting Ocean Acidification Under Global Change
Coral reefs are vulnerable to ocean acidification (Copyright (c) 2004 Richard Ling)
Emissions of carbon dioxide are causing ocean acidification as well as global warming. Scientists have previously used computer simulations to quantify how curbing of carbon dioxide emissions would mitigate climate impacts. New computer simulations have now examined the likely effects of mitigation scenarios on ocean acidification trends. They show that both the peak year of emissions and post-peak reduction rates influence how much ocean acidity increases by 2100. Changes in ocean pH over subsequent centuries will depend on how much the rate of carbon dioxide emissions can be reduced in the longer term.
Largely as a result of human activities such as the burning of fossil fuels for energy and land-use changes such deforestation, the concentration of carbon dioxide in the atmosphere is now higher that it has been at any time over the last 800,000 years. Most scientists believe this increase in atmospheric carbon dioxide to be an important cause of global warming.
“The oceans absorb around a third of carbon dioxide emissions, which helps limit global warming, but uptake of carbon dioxide by the oceans also increases their acidity, with potentially harmful effects on calcifying organisms such as corals and the ecosystems that they support,” explained Dr Toby Tyrrell of the University of Southampton’s School of Ocean and Earth Science (SOES) based at the National Oceanography Centre, Southampton. (more…)
New Computer Model Advances Climate Change Research
Modeling climate’s complexity. This image, taken from a larger simulation of 20th century climate, depicts several aspects of Earth’s climate system. Sea surface temperatures and sea ice concentrations are shown by the two color scales. The figure also captures sea level pressure and low-level winds, including warmer air moving north on the eastern side of low-pressure regions and colder air moving south on the western side of the lows. Such simulations, produced by the NCAR-based Community Climate System Model, can also depict additional features of the climate system, such as precipitation. Companion software, recently released as the Community Earth System Model, will enable scientists to study the climate system in even greater complexity. (©UCAR)
Scientists can now study climate change in far more detail with powerful new computer software released by the National Center for Atmospheric Research (NCAR).
The Community Earth System Model (CESM) will be one of the primary climate models used for the next assessment by the Intergovernmental Panel on Climate Change (IPCC). The CESM is the latest in a series of NCAR-based global models developed over the last 30 years. The models are jointly supported by the Department of Energy (DOE) and the National Science Foundation, which is NCAR’s sponsor.
Scientists and engineers at NCAR, DOE laboratories, and several universities developed the CESM.
The new model’s advanced capabilities will help scientists shed light on some of the critical mysteries of global warming, including:
* What impact will warming temperatures have on the massive ice sheets in Greenland and Antarctica?
* How will patterns in the ocean and atmosphere affect regional climate in coming decades?
* How will climate change influence the severity and frequency of tropical cyclones, including hurricanes?
* What are the effects of tiny airborne particles, known as aerosols, on clouds and temperatures?
The CESM is one of about a dozen climate models worldwide that can be used to simulate the many components of Earth’s climate system, including the oceans, atmosphere, sea ice, and land cover. The CESM and its predecessors are unique among these models in that they were developed by a broad community of scientists. The model is freely available to researchers worldwide. (more…)
Powering Australia with Waves
Coledale Beach south of Sydney, New South Wales
Wave energy is surging ahead as a viable source of renewable energy to generate electricity — with Australia’s southern margin identified by the World Energy Council as one of the world’s most promising sites for wave-energy generation.
One problem for wave-energy developers, however, is that previous estimates of wave-energy potential are based on information in deep ocean water, while “wave-energy generation systems are typically positioned near to shore,” says physical oceanographer Mark Hemer of Australia’s CSIRO Wealth for Oceans National research flagship.
In a paper in the AIP’s Journal of Renewable and Sustainable Energy, Hemer and colleague David Griffin provide new estimates of the wave-energy potential of Australia’s near-shore regions. They also calculate how much of Australia’s energy needs could be obtained from wave energy alone. Australia’s present-day electricity consumption is 130,000 gigawatt-hours/year. Hemer and Griffin show that if 10 percent of the near-shore wave energy available along Australia’s Southern coastline could be converted into electricity, half of the country’s present-day electricity consumption would be met. (more…)
Measuring Salt Shine to Improve Climate Understanding
Lake Tuz
From 14 - 25 August 2010, scientists from around the world will gather in Southern Turkey to measure the spectral reflectance of a few square kilometres of salt. These measurements will have a major impact on the future of satellite based Earth observation, and will ultimately improve our understanding of the Earth’s climate.
For ten months of the year Tuz Gölü (Lake Tuz) in southern Turkey appears to be like any other lake. However, during July and August it dries to become a bright, pristine, white surface, which is ideal for calibrating Earth observation satellites.
Tuz Gölü is one of eight sites recently endorsed by the Committee on Earth Observation Satellites (CEOS) to become an international reference standard to evaluate satellites’ sensor-to-sensor biases, and also to calibrate/validate their radiometric performance.
Observing the dynamic Earth
Satellite sensors are known to degrade significantly in-orbit. So it is very difficult to have confidence in any pre-flight assigned value of their radiometric characteristics. This makes measurements of subtle changes of the Earth (as needed for monitoring climate change) challenging. (more…)
Impacts of Climate Change on Mussels
Climate change is causing higher air and water temperatures along the east coast of the United States. These changes have shrunk the geographic region where blue mussels are able to survive, according to findings by University of South Carolina researchers published in the Journal of Biogeography.
Mytilus edulis, or blue mussels, a popular seafood, used to live along the East Coast as far south as Cape Hatteras, North Carolina, but now exist only as far south as Lewes, Delaware, according to Sierra Jones, a PhD student in the Department of Biological Sciences at USC.
Most plants and animals have geographic ranges defined by northern and southern limits. In many cases, ranges are thought to be controlled by temperature, and if it becomes too hot, the limits will shift. However, linking changes in geographic range to changes in climate is difficult unless long-term records in distribution are compared to equally long-term records of weather.
Spanning over 300 miles of coastline, Jones and colleagues explored how survival of mussels changed across latitudes and decades with respect to temperature. As recently as sixty years ago, these mussels thrived as far south as North Carolina. Due to air and water temperature increases over the past sixty years, they no longer survive throughout the year south of Lewes, Delaware, and populations to the north now experience higher rates of mortality than in the past. (more…)
Global Warming and Floods
The world is witnessing extreme climate change, natural disasters and massive devastation.
Global warming may be responsible for a variety of natural disasters wreaking havoc in numerous regions of the world.
Climate Change Affects Geographical Range of Plants
Mats Töpel is part of the Department of Plant and Environmental Sciences at the University of Gothenburg. (University of Gothenburg)
Researches at the University of Gothenburg have shown how climate change many million years ago has influenced the geographical range of plants by modelling climate preferences for extinct species. The method can also be used to predict what effects climate change of today and tomorrow will have on future distributions of plants and animals.
The researcher Mats Töpel at the Department of Plant and Environmental Sciences, University of Gothenburg, has studied how climate change has influenced the development of a group of plants in the genus Potentilla, commonly known as cinquefoils.
His research shows that this group of plants developed during a period of climate change in western North America around 25 million years ago, which led to summer drought in California and the largest desert in North America, the Great Basin.
The small plant Ivesia bailey is adapted to living in extremely dry conditions, by seeking shade on north-facing rocks in the Nevada Desert. This lifestyle is believed to have evolved in the genus Potentilla around 20 million years ago.
Models of the climate
“By creating models of the climate in which the group probably evolved, I have shown that there was a suitable climate in the eastern part of the Great Basin approximately 25 million years ago, and that the geographical range of these plants expanded to the west at the same time as new species evolved and adapted to different types of environments. (more…)
U.S. Greenhouse Gas Emissions and Capture, Regionally
A new report, Agriculture’s Role in Greenhouse Gas Emissions and Capture, commissioned by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, examines the evidence for greenhouse gas (GHG) emissions and sequestration in America’s major agroecosystems.
The report summarizes current knowledge of carbon dioxide (CO2), nitrous oxide (N2O) and methane (CH4) emissions and capture across six regions—Northeast, Southeast, Corn Belt, Northern Great Plains, Southern Great Plains, and Pacific—as influenced by cropping system, tillage, and soil management. The report also outlines conservation agricultural systems and practices including: no-till, reduced tillage, cover crops, leguminous green manures, and nutrient-use efficiency—that, when adopted, will result in increased capture and reduced emissions of these GHGs. Additionally, critical knowledge gaps for research are identified. The full report can be viewed online at: https://www.agronomy.org/files/science-policy/ghg-report-august-2010.pdf.
American Society of Agronomy President Fran Pierce said, “This timely report identifies critical knowledge gaps that must be addressed to provide America’s farmers with the management strategies and tools needed to increase carbon sequestration and reduce GHG emissions. Pierce added that, “Adoption of conservation agricultural systems, in addition to reducing emissions of GHGs, also enhances the productivity of our nation’s agroecosystems, thereby ensuring future domestic and global food and energy security.” (more…)
Climate Models Indicate Future Holds Stronger, Longer Heat Waves for Mid-Latitudes
Orange County, Indiana
Heat waves are a growing concern and current climate models indicate they will increase in duration and intensity especially in the mid-latitudes of which Indiana and the Midwest is a part,” says climate researcher and Indiana University-Purdue University Indianapolis (IUPUI) Professor Daniel Johnson.
“Heat waves are known to kill hundreds of people in the United States every year and are the leading cause of weather-related fatalities; usually outstripping the combined effects of hurricanes, tornadoes, lightning and flash floods. ”
“One of the most likely disasters to strike the Central Indiana region is an extreme heat event of considerable duration and strength, the researcher says.
Johnson, a geography professor in the School of Liberal Arts at IUPUI, and colleagues of the Indiana University Institute for Research and Social Issues, are currently conducting two studies on the impact of heat waves on vulnerable populations within urbanized areas. The goal is to develop vulnerability models designed to assist emergency personnel in their response and mitigation to heat wave incidents. (more…)
Charcoal Takes Some Heat Off Global Warming
Biochar technology can help us bring down carbon dioxide to 350 ppm.
As much as 12 percent of the world’s human-caused greenhouse gas emissions could be sustainably offset by producing biochar, a charcoal-like substance made from plants and other organic materials. That’s more than what could be offset if the same plants and materials were burned to generate energy, concludes a study published today in the journal Nature Communications.
“These calculations show that biochar can play a significant role in the solution for the planet’s climate change challenge,” said study co-author Jim Amonette, a soil chemist at the Department of Energy’s Pacific Northwest National Laboratory. “Biochar offers one of the few ways we can create power while decreasing carbon dioxide levels in the atmosphere. And it improves food production in the world’s poorest regions by increasing soil fertility. It’s an amazing tool.”
The study is the most thorough and comprehensive analysis to date on the global potential of biochar. The carbon-packed substance was first suggested as a way to counteract climate change in 1993. Scientists and policymakers have given it increasing attention in the past few years. The study was conducted by Dominic Woolf and Alayne Street-Perrott of Swansea University in Wales, U.K., Johannes Lehmann of Cornell University in Ithaca, N.Y., Stephen Joseph of the University of New South Wales, Australia, and Amonette. (more…)
Common Orchid Gives Scientists Hope in Face of Climate Change
Inside the Jodrell laboratory
A study led by scientists from the Royal Botanic Gardens, Kew’s Jodrell Laboratory, which focuses on epigenetics in European common marsh orchids, has revealed that some plants may be able to adapt more quickly to environmental change than previously thought. The new study, published in Molecular Biology and Evolution, brings new hope to plant conservation.
Epigenetics comprises hidden influences upon gene functions that occur without a change in the DNA sequence, but are potentially inheritable, and it is a new field of research that is reshaping the way scientists look at the living world. This new evidence that environmental effects on gene activity can be ‘remembered’ is hugely significant. In the modern interpretation of Darwin’s theory of evolution, scientists previously thought that genetic mutations (permanent changes in DNA sequence) were the only source of new traits that could be handed down from generation to generation, causing changes to the way species react to their environment. This process of adaptation can take hundreds of years and is almost certainly too slow for plants to adapt to rapid climate change.
However, in this cutting-edge study on a group of marsh orchids, Kew scientists have found that epigenetic variation can significantly influence the adaptive potential of an individual species. In turn, this affects the evolutionary potential of a species at a much quicker rate than was previously thought. (more…)
Higher Temperatures to Slow Asian Rice Production
By Rex Graham
Rising temperatures during the past 25 years have already cut the yield growth rate by 10–20 percent in several rice-growing locations.
Production of rice—the world’s most important crop for ensuring food security and addressing poverty—will be thwarted as temperatures increase in rice-growing areas with continued climate change, according to a new study by an international team of scientists.
The research team found evidence that the net impact of projected temperature increases will be to slow the growth of rice production in Asia. Rising temperatures during the past 25 years have already cut the yield growth rate by 10–20 percent in several locations.
Published in the online early edition the week of Aug. 9, 2010 in Proceedings of the National Academy of Sciences —a peer-reviewed, scientific journal from the United States—the report analyzed six years of data from 227 irrigated rice farms in six major rice-growing countries in Asia, which produces more than 90 percent of the world’s rice.
“We found that as the daily minimum temperature increases, or as nights get hotter, rice yields drop,” said Jarrod Welch, lead author of the report and graduate student of economics at the University of California, San Diego. (more…)
Greenland Glacier Calves Huge Ice Island
Satellite image from Aug. 5, 2010, shows the huge ice island calved from Greenland's Petermann Glacier. (Courtesy of Prof. Andreas Muenchow, University of Delaware)
A University of Delaware researcher reports that an “ice island” four times the size of Manhattan has calved from Greenland’s Petermann Glacier. The last time the Arctic lost such a large chunk of ice was in 1962.
“In the early morning hours of August 5, 2010, an ice island four times the size of Manhattan was born in northern Greenland,” said Andreas Muenchow, associate professor of physical ocean science and engineering at the University of Delaware’s College of Earth, Ocean, and Environment. Muenchow’s research in Nares Strait, between Greenland and Canada, is supported by the National Science Foundation (NSF).
Satellite imagery of this remote area at 81 degrees N latitude and 61 degrees W longitude, about 620 miles [1,000 km] south of the North Pole, reveals that Petermann Glacier lost about one-quarter of its 43-mile long [70 km] floating ice-shelf.
Trudy Wohlleben of the Canadian Ice Service discovered the ice island within hours after NASA’s MODIS-Aqua satellite took the data on Aug. 5, at 8:40 UTC (4:40 EDT), Muenchow said. These raw data were downloaded, processed, and analyzed at the University of Delaware in near real-time as part of Muenchow’s NSF research. (more…)
Planted and Unplanted Man-Made Wetlands are Similar at Year 15, And Function as Effective Carbon Sinks
A 15-year experiment in an outdoor “laboratory” on Ohio State University’s campus shows that naturally colonizing wetlands can offer just as many, if not more, ecological services as will wetlands planted by humans.
Researchers at Ohio State have been comparing the behavior of two experimental marshes on the campus, one that was planted in 1994 with wetland vegetation and another that was left to colonize plant and animal life on its own. The 2 ½-acre marshes are part of the Wilma H. Schiermeier Olentangy River Wetland Research Park, a 30-acre complex that functions as a “living laboratory” in ecological science.
After year 15, the two wetlands contained nearly the same number of plant species, and their rates of retaining phosphorus and nitrates – nutrients that can become potential water contaminants – were almost identical. Both wetlands also hold carbon in their soil, with this carbon sink function increasing steadily over the years.
Plant productivity and greenhouse gas emissions were two ways in which the wetlands differed at this stage in their lives: The naturally developing wetland produced more plant biomass and emits more of the greenhouse gas methane, the latter because it contains more decayed organic material from the higher biomass production. Bacteria that produce methane during that decaying process cause wetlands to release the gas into the atmosphere. (more…)
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