Methane clathrates and climate change
http://en.wikipedia.org/wiki/Methane...climate_change
Main article: Clathrate Gun Hypothesis
Methane is a powerful greenhouse gas. Despite its short atmospheric half life of 7 years, methane has a global warming potential of 62 over 20 years and 21 over 100 years (IPCC, 1996; Berner and Berner, 1996; vanLoon and Duffy, 2000). The sudden release of large amounts of natural gas from methane clathrate deposits has been hypothesized as a cause of past and possibly future climate changes. Events possibly linked in this way are the Permian-Triassic extinction event, the Paleocene-Eocene Thermal Maximum.
Climate scientists such as James Hansen expect that methane clathrates in the permafrost regions will be released as a result of global warming, unleashing powerful feedback forces which may cause runaway climate change that cannot be controlled.
Recent research carried out in 2008 in the Siberian Arctic has shown millions of tons of methane being released[23][24][25][26][27] with concentrations in some regions reaching up to 100 times above normal[28][29].
^ Compare: Methane bubbling through seafloor creates undersea hills, Monterey Bay Aquarium Research Institute, 5 February 2007
^ Translation of a blog entry by Örjan Gustafsson, expedition research leader, 2 September 2008
^ N. Shakhova, I. Semiletov, A. Salyuk, D. Kosmach, and N. Bel’cheva (2007), Methane release on the Arctic East Siberian shelf, Geophysical Research Abstracts, 9, 01071
^ N. Shakhova, I. Semiletov, A. Salyuk, D. Kosmach (2008), Anomalies of methane in the atmosphere over the East Siberian shelf: Is there any sign of methane leakage from shallow shelf hydrates?, EGU General Assembly 2008, Geophysical Research Abstracts, 10, EGU2008-A-01526
^ Volker Mrasek, A Storehouse of Greenhouse Gases Is Opening in Siberia, Spiegel International Online, 17 April 2008
5 February 2007 For Immediate Release
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Methane bubbling through seafloor creates undersea hills
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According to Paull, "We don't know if this gas and sediment was burped up in a single year, or moved slowly like a glacier." In either case, Paull's data suggest that pingo-like features are growing in response to warming that started thousands of years ago. Thus, their growth is not a result of human-induced global warming. However, Paull's research does show that pingo-like features are still growing and releasing methane today.
Because methane is a potent greenhouse gas, climate scientists would like to know how much is bubbling up from the seafloor worldwide. Future research on methane hydrates and pingo-like features may help address this question. As Paull phrased it, "Pingo-like features are one of the places where we see methane coming up through the seafloor. As yet we don't know how important they are, since we don't know how much gas is coming up in the Arctic as a whole or in other seafloor areas."
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http://www.mbari.org/news/news_relea...aull-plfs.html