‘Dry Water’ Could Store Carbon Diioxide Commercially
Powdered material called "dry water" could provide a new way to store carbon dioxide in an effort to fight global warming. (Credit: Ben Carter)
An unusual substance known as “dry water,” which resembles powdered sugar, could provide a new way to absorb and store carbon dioxide, the major greenhouse gas that contributes to global warming, scientists reported here today at the 240th National Meeting of the American Chemical Society.
The powder shows bright promise for a number of other uses, they said. It may, for instance, be a greener, more energy-efficient way of jumpstarting the chemical reactions used to make hundreds of consumer products. Dry water also could provide a safer way to store and transport potentially harmful industrial materials.
“There’s nothing else quite like it,” said Ben Carter, Ph.D., researcher for study leader Professor Andrew Cooper. “Hopefully, we may see ‘dry water’ making waves in the future.”
Carter explained that the substance became known as “dry water” because it consists of 95 percent water and yet is a dry powder. Each powder particle contains a water droplet surrounded by modified silica, the stuff that makes up ordinary beach sand. The silica coating prevents the water droplets from combining and turning back into a liquid. The result is a fine powder that can slurp up gases, which chemically combine with the water molecules to form what chemists term a hydrate. (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…)
Hollow Fibers May Lead to Cost-Effective Carbon Capture
Georgia Tech researcher Carson Meredith is shown with a high-throughput sorption measurement system developed in his lab to screen up to 36 samples of adsorbent simultaneously. It will be used to evaluate metal-organic framework materials used in membranes. (Credit: Gary Meek)
Researchers at the Georgia Institute of Technology are using funding from the Advanced Research Projects Agency - Energy – also known as ARPA-E – to pursue two different, but related, approaches for removing carbon dioxide from the flue gases of coal-burning power plants.
Power plants produce approximately one-third of all carbon dioxide emitted in the United States each year. The researchers will attempt to use the unique high-density properties of hollow fibers to develop cost-effective techniques for removing large volumes of the greenhouse gas from the emissions.
In one project, awarded directly to Georgia Tech, researchers are developing hollow-fiber composite membranes that will use nanoporous metal-organic framework materials to separate carbon dioxide from the flue gases. In the other project, Georgia Tech researchers are assisting colleagues at Oak Ridge National Laboratory in developing hollow-fiber sorbents that will soak up carbon dioxide like a sponge – then release it when heated. (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…)
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…)
Ice-Free Ocean May Not Absorb CO2, A Component in Global Warming
by Philip Lee Williams
A Chinese-American research team working in the Arctic has found that the melted waters in summer may be less help in absorbing atmospheric carbon dioxide than earlier thought. Photo taken by Dr. Jianfang Chen, State Ocean Administration of China - Second Institute of Oceanography, Hangzhou, China.
The summer of 2010 has been agonizingly hot in much of the continental U.S., and the record-setting temperatures have refocused attention on global warming. Scientists have been looking at ways the Earth might benefit from natural processes to balance the rising heat, and one process had intrigued them, a premise that melting ice at the poles might allow more open water that could absorb carbon dioxide, one of the major compounds implicating in warming.
Now, though, in research just published in the journal Science and led by a University of Georgia marine chemist, that idea may be one more dead end. In fact, a survey of waters in the Canada Basin, which extends north of Alaska to the North Pole, shows that its value as a potential carbon dioxide “sink” may be short-lived at best and minor in terms of what the planet will need to avoid future problems.
“The Canada Basin and entire Arctic Ocean are still taking up carbon dioxide,” said Wei-Jun Cai, a professor in the department of marine sciences in UGA’s Franklin College of Arts and Sciences and lead author of the study. “But our research shows that as the ice melts, the carbon dioxide in the water very quickly reaches equilibrium with the atmosphere, so its use as a place to store CO2 declines dramatically and quickly. We never really understood how limited these waters would be in terms of their usefulness in soaking up carbon dioxide.” (more…)
Unaccounted Feedbacks from Climate-Induced Ecosystem Changes May Increase Future Climate Warming
The terrestrial biosphere regulates atmospheric composition, and hence climate. Projections of future climate changes already account for “carbon-climate feedbacks”, which means that more CO2 is released from soils in a warming climate than is taken up by plants due to photosynthesis. Climate changes will also lead to increases in the emission of CO2 and methane from wetlands, nitrous oxides from soils, volatile organic compounds from forests, and trace gases and soot from fires. All these emissions affect atmospheric chemistry, including the amount of ozone in the lower atmosphere, where it acts as a powerful greenhouse gas as well as a pollutant toxic to people and plants.
Although our understanding of other feedbacks associated with climate-induced ecosystem changes is improving, the impact of these changes is not yet accounted for in climate-change modelling. An international consortium of scientists, led by Almut Arneth from Lund University, has estimated the importance of these unaccounted “biogeochemical feedbacks” in an article that appears as Advance Online Publication on Nature Geoscience’s website on 25 July at 1800 London time. They estimate a total additional radiative forcing by the end of the 21st century that is large enough to offset a significant proportion of the cooling due to carbon uptake by the biosphere as a result of fertilization of plant growth. (more…)
CO2 Reduction Policies in Spain Strengthen the Services Sector
If technology evolves following the current trend, the best option is to reduce CO2 emissions as soon as possible. (Credit: SINC)
A study by the Basque Center for Climate Change (BC3) has analysed the expected economic impact in Spain of the reduction of greenhouse gases (GHGs) set by the Kyoto Protocol for the period 2008-2012 and for the phase afterwards or post-Kyoto phase. In addition, the services sector will come out on top in comparison to sectors such as industrial or energy sectors.
“CO2 restriction policies in Spain have an impact on the economy, in other words, making it lean more towards an economy of services. The weight of the industry and energy sectors is reduced, and this is due to the fact that there is a change in production and consumption patterns resulting from CO2 which will come at a price”, Mikel González-Eguino, author of the study and researcher for BC3 explains to SINC .
The study, which is published in the journal Investigación Económica also indicates that these policies encourage a minor change in consumption patterns. “The creation of a tax on CO2 may cause emissions to reduce, and change the habits related to large-scale energy consumption”, states the expert. (more…)
Warmer Climate Increases the Release of Carbon Dioxide by Inland Lakes
Much organically bound carbon is deposited on inland lake bottoms. A portion remains in the sediment, sometimes for thousands of years, while the rest is largely broken down to carbon dioxide and methane, which are released into the atmosphere. Swedish researchers have shown that carbon retention by sediment is highly temperature-sensitive and that a warmer climate would result in increased carbon dioxide emissions to the atmosphere. The study is published in the current issue of the journal Nature.
Particles of different kinds – including microscopic algae, other plankton and humus from surrounding land areas – are continuously deposited on lake bottoms. The breakdown of a portion of this matter by bacteria in the sediment contributes significantly to atmospheric carbon dioxide. Lake sediment nevertheless constitutes an important “carbon sink,” serving to store – sometimes for a very long time – a significant portion of the carbon-containing material that does not decompose.
To date, it has been unclear to what extent organic, carbon-containing material remains on lake bottoms, as opposed to being broken down. A group of researchers under the leadership of Professor Lars Tranvik at the Department of Limnology at Uppsala University has found a strong connection between the carbon dioxide production of lake sediment and bottom-water temperature. (more…)
NRC Report: Emission Choices Made Now Can Lock in Climate Changes for Centuries to Millennia
When it comes to our planet’s health, a group including a Texas Tech University climate researcher has devised a list of advice and recommendations for possible outcomes to consider when deciding about future emissions targets.
Choices made now about carbon dioxide emissions reductions will affect climate change and its impacts over the next few decades and in coming centuries and millennia, said Katharine Hayhoe, who contributed to a new report from the National Research Council.
The report is titled Climate Stabilization Targets: Emissions, Concentrations, and Impacts Over Decades to Millennia.
“Many of us have had the experience of going to the doctor and receiving advice on how to improve our health,” Hayhoe said. “Then, it’s up to us to decide how much we are willing to change. In a similar way, this report presents the probabilities of certain impacts at different levels of global temperature increase. But we, the scientists, can’t make the decisions of how much risk is acceptable. That’s a political decision. Rather, we’re trying to give policymakers the information they need to make these decisions.” (more…)
New ‘Smart’ Metal Could Mean Cool Cash for Consumers, Less CO2
A Maryland team developed the smart alloy here and is now ready to test a prototype. (Keck Laboratory for Combinatorial Nanosynthesis and Multiscale Characterization/ UM)
If a new “smart” metal could help cool your home or refrigerate your food 175 percent more efficiently than current technology, imagine what that would do for your electric bills.
Researchers at the University of Maryland are developing a new “thermally elastic” metal alloy for use in advanced refrigeration and air conditioning systems. The technology promises far greater efficiency and reductions in greenhouse gas emissions.
The Maryland team will soon begin testing of a prototype system, with economic stimulus funding from the U.S. Department of Energy. The new grant is part of a program designed to bring “game-changing” technologies to market.
“Air conditioning represents the largest share of home electric bills in the summer, so this new technology could have significant consumer impact, as well as an important environmental benefit,” says Eric Wachsman, director of the University of Maryland Energy Research Center (UMERC).
“The approach is expected to increase cooling efficiency 175 percent, reduce U.S. carbon dioxide emissions by 250 million metric tons per year, and replace liquid refrigerants that can cause environmental degradation in their own right,” Wachsman adds. (more…)
Global Warming Slows Coral Growth in Red Sea
Neal E. Cantin and Anne L. Cohen examine a Red Sea coral specimen just outside the hollow tube of a CT scanner. (Photo by Tom Kleindinst, Woods Hole Oceanographic Institution)
In a pioneering use of computed tomography (CT) scans, scientists at Woods Hole Oceanographic Institution (WHOI) have discovered that carbon dioxide (CO2)-induced global warming is in the process of killing off a major coral species in the Red Sea. As summer sea surface temperatures have remained about 1.5 degrees Celsius above ambient over the last 10 years, growth of the coral, Diploastrea heliopora, has declined by 30% and “could cease growing altogether by 2070” or sooner, they report in the July 16 issue of the journal Science.
“The warming in the Red Sea and the resultant decline in the health of this coral is a clear regional impact of global warming,” said Neal E. Cantin, a WHOI postdoctoral investigator and co-lead researcher on the project. In the 1980s, he said, “the average summer [water] temperatures were below 30 degrees Celsius. In 2008 they were approaching 31 degrees.”
Cantin and WHOI Research Specialist Anne L. Cohen, the other lead investigator, said the findings were unexpected because D. heliopora did not exhibit one of the typical signs of thermal stress: bleaching. “These corals looked healthy,” said Cohen. (more…)
Steam Process Could Help Sequester Carbon from Coal Burning Plants
A new process for regenerating carbon-capture materials provides another step toward removing carbon dioxide from the flue gases of coal-burning facilities like this one in Datteln, Germany. (Photo Arnold Paul, Wikimedia)
Because they can remove carbon dioxide from the flue gases of coal-burning facilities such as power plants, solid materials containing amines are being extensively studied as part of potential CO2 sequestration programs designed to reduce the impact of the greenhouse gas.
But although these adsorbent materials do a good job of trapping the carbon dioxide, commonly-used techniques for separating the CO2 from the amine materials – thereby regenerating them for re-use – seem unlikely to be suitable for high-volume industrial applications.
Now, researchers have demonstrated a relatively simple regeneration technique that could utilize waste steam generated by many facilities that burn fossil fuels. This steam-stripping technique could produce concentrated carbon dioxide ready for sequestration in the ocean or deep-earth locations – while readying the amine materials for further use.
“We have demonstrated an approach to developing a practical adsorption process for capturing carbon dioxide and then releasing it in a form suitable for sequestration,” said Christopher Jones, a professor in the School of Chemical & Biomolecular Engineering at the Georgia Institute of Technology.
The research was reported online June 23, 2010 in the early view version of the journal ChemSusChem. The work was supported by New York-based Global Thermostat, LLC., a company that is developing and commercializing technology for the direct capture of carbon dioxide from the air. (more…)
Plant ‘Breathing’ Mechanism Discovery Has Important Climate Change Implications
A tiny, little-understood plant pore has enormous implications for weather forecasting, climate change, agriculture, hydrology, and more. A study by scientists at the Carnegie Institution’s Department of Global Ecology, with colleagues from the Research Center Jülich in Germany, has now overturned the conventional belief about how these important structures called stomata regulate water vapor loss from the leaf–a process called transpiration. They found that radiation is the driving force of physical processes deep within the leaf. The research is published the week of July 12, 2010, in the on-line early edition of the Proceedings of the National Academy of Sciences.
Stomata are lip-shaped pores surrounded by a pair of guard cells that control the size of the opening. The size of the pores regulates the inflow of carbon dioxide (CO2 ) needed for photosynthesis and the outflow of water vapor to the atmosphere—transpiration.
Transpiration cools and humidifies the atmosphere over vegetation, moderating the climate and increasing precipitation. Stomata influence the rate at which plants can absorb CO2 from the atmosphere, which affects the productivity of plants and the concentration of atmospheric CO2. Understanding stoma is important for climate change research. (more…)
Carbon Emissions Threaten Fish Populations
Humanity’s rising CO2 emissions could have a significant impact on the world’s fish populations according to groundbreaking new research carried out in Australia.
Baby fish may become easy meat for predators as the world’s oceans become more acidic due to CO2 fallout from human activity, an international team of researchers has discovered.
In a series of experiments reported in the latest issue of the Proceedings of the National Academy of Science (PNAS), the team found that as carbon levels rise and ocean water acidifies, the behaviour of baby fish changes dramatically – in ways that decrease their chances of survival by 50 to 80 per cent.
“As CO2 increases in the atmosphere and dissolves into the oceans, the water becomes slightly more acidic. Eventually this reaches a point where it significantly changes the sense of smell and behaviour of larval fish,” says team leader Professor Philip Munday of the Australian Research Council’s Centre of Excellence for Coral Reef Studies (CoECRS) at James Cook University. (more…)
Scrubbing CO2 From Atmosphere Could Be a Long-Term Commitment
Ken Caldeira (Courtesy of the Carnegie Institution)
With carbon dioxide in the atmosphere approaching alarming levels, even halting emissions altogether may not be enough to avert catastrophic climate change. Could scrubbing carbon dioxide from the air be a viable solution? A new study by scientists at the Carnegie Institution suggests that while removing excess carbon dioxide would cool the planet, complexities of the carbon cycle would limit the effectiveness of a one-time effort. To keep carbon dioxide at low levels would require a long-term commitment spanning decades or even centuries.
Previous studies have shown that reducing carbon dioxide emissions to zero would not lead to appreciable cooling, because carbon dioxide already within the atmosphere would continue to trap heat. For cooling to occur, greenhouse gas concentrations would need to be reduced. “We wanted to see what the response would be if carbon dioxide were actively removed from the atmosphere,” says study coauthor Ken Caldeira of Carnegie’s Department of Global Ecology. “Our study is the first to look at how much carbon dioxide you would need to remove and for how long to keep atmospheric carbon dioxide concentrations low. This has obvious implications for the public and for policy makers as we weigh the costs and benefits of different ways of mitigating climate change.” (more…)
Arctic Climate May Be More Sensitive to Warming Than Thought, Says New Study
From left to right, Ashley Ballantyne of the University of Colorado at Boulder, Dara Finney of Environment Canada and Natalia Rybczynski of the Canadian Museum of Nature search for fossils in a peat deposit at Strathcona Fiord on Ellesmere Island in Canada's High Arctic. (Photo courtesy Dara Finney, Environment Canada)
A new study shows the Arctic climate system may be more sensitive to greenhouse warming than previously thought, and that current levels of Earth’s atmospheric carbon dioxide may be high enough to bring about significant, irreversible shifts in Arctic ecosystems.
Led by the University of Colorado at Boulder, the international study indicated that while the mean annual temperature on Ellesmere Island in the High Arctic during the Pliocene Epoch 2.6 to 5.3 million years ago was about 34 degrees Fahrenheit, or 19 degrees Celsius, warmer than today, CO2 levels were only slightly higher than present. The vast majority of climate scientists agree Earth is warming due to increased concentrations of heat-trapping atmospheric gases generated primarily by human activities like fossil fuel burning and deforestation.
The team used three independent methods of measuring the Pliocene temperatures on Ellesmere Island in Canada’s High Arctic. They included measurements of oxygen isotopes found in the cellulose of fossil trees and mosses that reveal temperatures and precipitation levels tied to ancient water, an analysis of the distribution of lipids in soil bacteria which correlate with temperature, and an inventory of ancient Pliocene plant groups that overlap in range with contemporary vegetation. (more…)
Human Impacts Significantly Altering Ocean Chemistry
WHOI chemist Scott Doney.(Tom Kleindinst, Woods Hole Oceanographic Institution)
Numerous studies are documenting the growing effects of climate change, carbon dioxide, pollution and other human-related phenomena on the world’s oceans. But most of those have studied single, isolated sources of pollution and other influences.
Now, a marine geochemist at the Woods Hole Oceanographic Institution (WHOI) has published a report in the latest issue of the journal Science that evaluates the total impact of such factors on the ocean and considers what the future might hold.
“What we do on land—agriculture, fossil fuel combustion and pollution—can have a profound impact on the chemistry of the sea,” says Scott C. Doney, a senior scientist at WHOI and author of the Science report. “A whole range of these factors have been studied in isolation but have not been put in a single venue.”
Doney’s paper represents a meticulous compilation of the work of others as well as his own research in this area, which includes ocean acidification, climate change, and the global carbon cycle.
He concludes that climate change, rising atmospheric carbon dioxide, excess nutrient inputs, and the many forms of pollution are “altering fundamentally the…ocean, often on a global scale and, in some cases, at rates greatly exceeding those in the historical and recent geological record.” (more…)
Carbon Dioxide is the Missing Link to Past Global Climate Changes
Timothy Herbert is a geological sciences professor at Brown University. (Credit: Brown University)
Increasingly, the Earth’s climate appears to be more connected than anyone would have imagined. El Nino, the weather pattern that originates in a patch of the equatorial Pacific, can spawn heat waves and droughts as far away as Africa.
Now, a research team led by Brown University has established that the climate in the tropics over at least the last 2.7 million years changed in lockstep with the cyclical spread and retreat of ice sheets thousands of miles away in the Northern Hemisphere. The findings appear to cement the link between the recent Ice Ages and temperature changes in tropical oceans. Based on that new link, the scientists conclude that carbon dioxide has played the lead role in dictating global climate patterns, beginning with the Ice Ages and continuing today.
“We think we have the simplest explanation for the link between the Ice Ages and the tropics over that time and the apparent role of carbon dioxide in the intensification of Ice Ages and corresponding changes in the tropics,” said Timothy Herbert, professor of geological sciences at Brown and the lead author of the paper in Science.
“It certainly supports the idea of global sensitivity of climate to carbon dioxide as the first order of control on global temperature patterns,” Herbert added, “but we don’t know why. The answer lies in the ocean, we’re pretty sure.” (more…)
Changing Chesapeake Bay Acidity Impacting Oyster Shell Growth
New research shows that the shell growth of Crassostrea virginica from Chesapeake Bay could be compromised by current levels of acidity in some Bay waters. (Chris Kelly, UMCES Horn Point Laboratory)
Acidity is increasing in some regions of the Chesapeake Bay even faster than is occurring in the open ocean, where it is now recognized that increased levels of atmospheric carbon dioxide dissolve in the seawater thereby making it more acidic. These more acidic conditions in key parts of Chesapeake Bay reduce rates of juvenile oyster shell formation, according to new research published in the journal Estuaries and Coasts. The study, conducted at the University of Maryland Center for Environmental Science, examined 23 years of water quality data and concluded that significant trends in acidity will have mixed impacts on juvenile oyster growth, with some areas becoming more acidic and others more alkaline.
“The regional changes in acidity revealed in our analysis are greater than what could be caused by increasing atmospheric carbon dioxide alone,” said lead author Dr. George Waldbusser of Oregon State University. “We are seeing a complex pattern of increasing acidity in the more saline regions of the Bay, but the opposite trend of decreasing acidity in the less saline waters of the Bay.” (more…)
Going Underground to Monitor Carbon Dioxide
Charles Carrigan
A technique originally, applied to monitor the flow of contaminants into shallow groundwater supplies, has been repurposed to monitor carbon dioxide pumped deep underground for storage.
Electric Resistance Tomography (ERT) has been installed to track where a plume of injected CO_ moves underground in an oil field (Cranfield Oilfield) near Natchez, Miss. The site is part of the Southeast Regional carbon dioxide Partnership (SECARB), a project that eventually will store more than one million tons of CO_ in underground formations.
The ERT project at Cranfield is the deepest (10,000 feet) subsurface application of the method to date. The previous record of 2,400 feet was held by a European sequestration project near Potsdam, Germany. ERT uses vertical electrode arrays, usually in a cross-well arrangement, to perform four-electrode measurements of changes in the spatial distribution of electrical resistance within a subsurface formation. Because the Cranfield site contains CO_, which is five times as resistive as its surroundings, ERT showed that significant resistance changes occurred during plume growth and movement.
“We can image the CO_ plume as the fluid is injected,” said geophysicist Charles Carrigan, the LLNL lead on the ERT project. “What we’ve seen is a movement of the plume outward from the injection well into the geologic formation used for storage. ” (more…)
CO2 Effects on Plants Increases Global Warming
Map of globe shows percentage of predicted warming due to the direct effect of carbon dioxide on plants. Carbon dioxide warms the Earth because it is a greenhouse gas in the atmosphere, but it also causes plants to provide less evaporative cooling. A study by Long Cao and Ken Caldeira of the Carnegie Institution for Science finds that in some places (darkest orange) over 25 percent of the warming from increased atmospheric carbon dioxide is a result of decreased evaporative cooling by plants.(Carnegie Institution)
Trees and other plants help keep the planet cool, but rising levels of carbon dioxide in the atmosphere are turning down this global air conditioner. According to a new study by researchers at the Carnegie Institution for Science, in some regions more than a quarter of the warming from increased carbon dioxide is due to its direct impact on vegetation. This warming is in addition to carbon dioxide’s better-known effect as a heat-trapping greenhouse gas. For scientists trying to predict global climate change in the coming century, the study underscores the importance of including plants in their climate models.
“Plants have a very complex and diverse influence on the climate system,” says study co-author Ken Caldeira of Carnegie’s Department of Global Ecology. “Plants take carbon dioxide out of the atmosphere, but they also have other effects, such as changing the amount of evaporation from the land surface. It’s impossible to make good climate predictions without taking all of these factors into account.”
Plants give off water through tiny pores in their leaves, a process called evapotranspiration that cools the plant, just as perspiration cools our bodies. On a hot day, a tree can release tens of gallons of water into the air, acting as a natural air conditioner for its surroundings. The plants absorb carbon dioxide for photosynthesis through the same pores (called stomata). But when carbon dioxide levels are high, the leaf pores shrink. This causes less water to be released, diminishing the tree’s cooling power. (more…)
Through the Looking Glass: Scientists Peer Back at a Warm, Sub-Tropical Antarctica
Dawn patrol: ice observer Diego Mello and first mate Steve Bradley on the lookout for icebergs. (John Beck, IODP/TAMU)
Researchers brave rough seas and dodge icebergs to retrieve sediment cores that tell tales of early climates
New results from a research expedition in Antarctic waters may provide critical clues to understanding one of the most dramatic periods of climate change in Earth’s history.
Some 53 million years ago, Antarctica was a warm, sub-tropical environment. During this same period, known as the “greenhouse” or “hothouse” world, atmospheric carbon dioxide levels exceeded those of today by ten times.
Then suddenly, Antarctica’s lush environment transitioned into its modern icy realm.
Newly acquired climate records tell a tale of this long-ago time. The records were recovered from Antarctica, preserved in sediment cores retrieved during the Integrated Ocean Drilling Program (IODP) Wilkes Land Glacial History Expedition from Jan. 4 - March 8, 2010. (more…)
Soil Microbes Produce Less Atmospheric CO2 Than Expected With Climate Warming
Fungi such as this Laccaria species in Alaskan boreal forest are key drivers of the carbon cycle. (Photo by Steve Allison / UC Irvine)
The physiology of microbes living underground could determine the amount of carbon dioxide emitted from soil on a warmer Earth, according to a study published online this week in Nature Geoscience.
Researchers at UC Irvine, Colorado State University and the Yale School of Forestry & Environmental Studies found that as global temperatures increase, microbes in soil become less efficient over time at converting carbon in soil into carbon dioxide, a key contributor to climate warming.
Microbes, in the form of bacteria and fungi, use carbon for energy to breathe, or respire, and to grow in size and in number. A model developed by the researchers shows microbes exhaling carbon dioxide furiously for a short period of time in a warmer environment, leaving less carbon to grow on. As warmer temperatures are maintained, the less efficient use of carbon by the microbes causes them to decrease in number, eventually resulting in less carbon dioxide being emitted into the atmosphere. (more…)
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