Two articles on role of methane gas, a more powerful force for global warming than carbon dioxide. Methane Burps: Ticking Time Bomb By John Atcheson The Arctic Council's recent report on the effects of global warming in the far north paints a grim picture: global floods, extinction of polar bears and other marine mammals, collapsed fisheries. But it ignored a ticking time bomb buried in the Arctic tundra. There are enormous quantities of naturally occurring greenhouse gases trapped in ice-like structures in the cold northern muds and at the bottom of the seas. These ices, called clathrates, contain 3,000 times as much methane as is in the atmosphere. Methane is more than 20 times as strong a greenhouse gas as carbon dioxide. Now here's the scary part. A temperature increase of merely a few degrees would cause these gases to volatilize and "burp" into the atmosphere, which would further raise temperatures, which would release yet more methane, heating the Earth and seas further, and so on. There's 400 gigatons of methane locked in the frozen arctic tundra - ... Full story at: http://www.energybulletin.net/3647.html Methane Bubbling From Arctic Lakes, Now And At End Of Last Ice Age UAF researcher Katey Walter lights a pocket of methane on a thermokarst lake in Siberia in March of 2007. Igniting the gas is a way to demonstrate, in the field, that it contains methane. (Credit: Photo by Sergey Zimov)ScienceDaily (Oct. 26, 2007) — A team of scientists led by a researcher at the University of Alaska Fairbanks has identified a new likely source of a spike in atmospheric methane coming out of the North during the end of the last ice age. Methane bubbling from arctic lakes could have been responsible for up to 87 percent of that methane spike, said UAF researcher Katey Walter, lead author of a report printed in the Oct. 26 issue of Science. The findings could help scientists understand how current warming might affect atmospheric levels of methane, a gas that is thought to contribute to climate change. "It tells us that this isn't just something that is ongoing now. It would have been a positive feedback to climate warming then, as it is today," said Walter. "We estimate that as much as 10 times the amount of methane that is currently in the atmosphere will come out of these lakes as permafrost thaws in the future. The timing of this emission is uncertain, but likely we are talking about a time frame of hundreds to thousands of years, if climate warming continues as projected." Ice cores from Greenland and Antarctica have shown that during the early Holocene Period--about 14,000 to 11,500 years ago--the levels of methane in the atmosphere rose significantly, Walter said. "They found that an unidentified northern source (of methane) appeared during that time." Previous hypotheses suggested that the increase came from gas hydrates or wetlands. This study's findings indicate that methane bubbling from thermokarst lakes, which are formed when permafrost thaws rapidly, is likely a third and major source. Full article at: http://www.sciencedaily.com/releases/2007/10/071025174618.htm 5 February 2007 According to a recent paper published by MBARI geologists and their colleagues, methane gas bubbling through seafloor sediments has created hundreds of low hills on the floor of the Arctic Ocean. These enigmatic features, which can grow up to 40 meters (130 feet) tall and several hundred meters across, have puzzled scientists ever since they were first discovered in the 1940s. This conceptual drawing (not to scale) shows Paull's hypothesis that methane gas from deep hydrate deposits could push sediment up from below the ocean bottom to create a pingo-like feature. The gray lines in the background are from a seismic profile through one of these enigmatic features. Image: (c) 2007 MBARI Writing in the January issue of Geophysical Research Letters, MBARI geologists Charlie Paull and William Ussler and their coauthors described the results of field work they conducted on the Beaufort Sea Shelf, offshore of the north coast of Canada. In this area of year-round sea ice and permafrost, the team spent over a month mapping the seafloor and collecting sediment cores and gas samples from these underwater hills, which they call "pingo-like features." ... Full article at: http://www.mbari.org/news/news_releases/2007/paull-plfs.html

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