A more potent greenhouse gas than carbon dioxide, methane emissions will leap as Earth warms

While carbon dioxide is typically painted as the bad boy of greenhouse gases, methane is roughly 30 times more potent as a heat-trapping gas. New research in the journal Nature indicates that for each degree that Earth’s temperature rises, the amount of methane entering the atmosphere from microorganisms dwelling in lake sediment and freshwater wetlands — the primary sources of the gas — will increase several times. As temperatures rise, the relative increase of methane emissions will outpace that of carbon dioxide from these sources, the researchers report.The findings condense the complex and varied process by which methane — currently the third most prevalent greenhouse gas after carbon dioxide and water vapor — enters the atmosphere into a measurement scientists can use, explained co-author Cristian Gudasz, a visiting postdoctoral research associate in Princeton’s Department of Ecology and Evolutionary Biology. In freshwater systems, methane is produced as microorganisms digest organic matter, a process known as “methanogenesis.” This process hinges on a slew of temperature, chemical, physical and ecological factors that can bedevil scientists working to model how Earth’s systems will contribute, and respond, to a hotter future.The researchers’ findings suggest that methane emissions from freshwater systems will likely rise with the global temperature, Gudasz said. But to not know the extent of methane contribution from such a widely dispersed ecosystem that includes lakes, swamps, marshes and rice paddies leaves a glaring hole in climate projections.”The freshwater systems we talk about in our paper are an important component to the climate system,” Gudasz said. “There is more and more evidence that they have a contribution to the methane emissions. Methane produced from natural or humanmade freshwater systems will increase with temperature.”To provide a simple and accurate way for climate modelers to account for methanogenesis, Gudasz and his co-authors analyzed nearly 1,600 measurements of temperature and methane emissions from 127 freshwater ecosystems across the globe.The researchers found that a common effect emerged from those studies: freshwater methane generation very much thrives on high temperatures. Methane emissions at 0 degrees Celsius would rise 57 times higher when the temperature reached 30 degrees Celsius, the researchers report. For those inclined to model it, the researchers’ results translated to a temperature dependence of 0.96 electron volts (eV), an indication of the temperature-sensitivity of the methane-emitting ecosystems.”We all want to make predictions about greenhouse gas emissions and their impact on global warming,” Gudasz said. “Looking across these scales and constraining them as we have in this paper will allow us to make better predictions.”Story Source:The above story is based on materials provided by Princeton University. …

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Cost of Arctic methane release could be ‘size of global economy’, experts warn

July 24, 2013 — Researchers have warned of an “economic time-bomb” in the Arctic, following a ground-breaking analysis of the likely cost of methane emissions in the region.Economic modelling shows that the methane emissions caused by shrinking sea ice from just one area of the Arctic could come with a global price tag of 60 trillion dollars — the size of the world economy in 2012.Writing in a Comment piece in the journal, Nature, academics argue that a significant release of methane from thawing permafrost in the Arctic could have dire implications for the world’s economy. The researchers, from Cambridge and Rotterdam, have for the first time calculated the potential economic impact of a scenario some scientists consider increasingly likely — that methane from the East Siberian Sea will be emitted as a result of the thaw.This constitutes just a fraction of the vast reservoirs of methane in the Arctic, but scientists believe that the release of even a small proportion of these reserves could trigger possibly catastrophic climate change. According to the new assessment, the emission of methane below the East Siberian Sea alone would also have a mean global impact of 60 trillion dollars.The ground-breaking Comment piece was co-authored by Gail Whiteman, from Erasmus University; Chris Hope, Reader in Policy Modelling at Cambridge Judge Business School, University of Cambridge; and Peter Wadhams, Professor of Ocean physics at the University of Cambridge.”The global impact of a warming Arctic is an economic time-bomb,” Whiteman, who is Professor of sustainability, management and climate change at Rotterdam School of Management, Erasmus University (RSM), said.Wadhams added: “The imminent disappearance of the summer sea ice in the Arctic will have enormous implications for both the acceleration of climate change, and the release of methane from off-shore waters which are now able to warm up in the summer. This massive methane boost will have major implications for global economies and societies.”Most discussion about the economic implications of a warming Arctic focuses on benefits to the region, with increased oil-and-gas drilling and the opening up of new shipping routes that could attract investments of hundreds of billions of dollars. However, the effects of melting permafrost on the climate and oceans will be felt globally, the authors argue.Applying an updated version of the modelling method used in the UK government’s 2006 Stern Review on the Economics of Climate Change, and currently used by the US Environmental Protection Agency, the authors calculate the global consequences of the release of 50 gigatonnes of methane over a decade from thawing permafrost beneath the East Siberian Sea.”The methane release would bring forward the date at which the global mean temperature rise exceeds 2 degrees C by between 15 and 35 years,” said Chris Hope. “In the absence of climate-change mitigation measures, the PAGE09 model calculates that it would increase mean global climate impacts by $60 trillion.”If other impacts such as ocean acidification are factored in, the cost would be much higher. Some 80% of these costs will be borne by developing countries, as they experience more extreme weather, flooding, droughts and poorer health, as Arctic warming affects climate.The research also explored the impact of a number of later, longer-lasting or smaller pulses of methane, and the authors write that, in all these cases, the economic cost for physical changes to the Arctic is “steep.”The authors write that global economic institutions and world leaders should “kick-start investment in rigorous economic modelling” and consider the impacts of a changing Arctic landscape as far outweighing any “short-term gains from shipping and extraction.”They argue that economic discussions today are missing the big picture on Arctic change. “Arctic science is a strategic asset for human economies because the region drives critical effects in our biophysical, political and economic systems,” write the academics. Neither the World Economic Forum nor the International Monetary Fund currently recognise the economic danger of Arctic change.According to Whiteman, “Global leaders and the WEF and IMF need to pay much more attention to this invisible time-bomb. The mean impacts of just this one effect — $60 trillion — approaches the $70-trillion value of the world economy in 2012.”

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Vast methane-based ecosystem uncovered

May 22, 2013 — A marine research expedition sponsored by the U.S. Bureau of Ocean Energy Management (BOEM) and the National Oceanic and Atmospheric Administration (NOAA) has led to the discovery of perhaps the world’s largest methane cold seep by two university-based research teams and their partners, UNCW announced today.

The seep lies deep in the western North Atlantic Ocean, far from the life-sustaining energy of the sun. Mussels blanketing the the seep rely on bacteria that use the methane to make energy. The process, known as chemosynthesis, forms the basis for life in the harsh environment and could help scientists better understand how organisms can survive under these types of extreme conditions.

“UNCW and FSU have done two previous cruises together and this is perhaps our biggest discovery,” said UNCW researcher Dr. Steve Ross. “Studies of this kind and of these communities help scientists understand how life thrives in harsh environments, and perhaps even on other planets.”

The new seep discovery is only the third documented seep site on the U.S. Atlantic Coast, and by far the most extensive; the two seep areas at this site are estimated to be at least a kilometer long and in places hundreds of meters across. Sea cucumbers were also seen tucked into the tight mounds of mussels and shrimp swam above them. Many species of fishes, including some with unusual behaviors, were also common around the unique ecosystem..

Stationed aboard NOAA’s Ronald H. Brown research vessel, the research teams used the diverse capabilities of the Woods Hole Oceanographic Institution’s Remotely Operated Vehicle (ROV), Jason II, to document and study the newly discovered methane seep.. The teams have been able to capture high definition video, sample the sediment at the site, collect live mussels for genetic and reproductive studies, collect large dead shells and rocks for aging analysis, take water samples to examine water chemistry, and sample associated animals to examine food webs.

The seep discovery could potentially play an important role in advancing scientific understanding of hydrocarbon resources and gas hydrates (important possible future energy resources) along the US continental slope .

Major funding for the research expedition was provided by the Bureau of Ocean Energy Management, with NOAA providing funding for the Ronald H. Brown and Jason ROV. US Geological Survey and other collaborators also provided a variety of resources.

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