Arctic Seafloor Methane Releases Double Previous Estimates

http://www.sciencedaily.com/releases/2013/11/131125172113.htm

Nov. 25, 2013 — The seafloor off the coast of Northern Siberia is releasing more than twice the amount of methane as previously estimated, according to new research results published in the Nov. 24 edition of the journal Nature Geoscience.

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"Increased methane releases in this area are a possible new climate-change-driven factor that will strengthen over time."

Methane is a greenhouse gas more than 30 times more potent than carbon dioxide. On land, methane is released when previously frozen organic material decomposes. In the seabed, methane can be stored as a pre-formed gas or asmethane hydrates. As long as the subsea permafrost remains frozen, it forms a cap, effectively trapping the methane beneath. However, as the permafrost thaws, it develops holes, which allow the methane to escape. These releases can be larger and more abrupt than those that result from decomposition.

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Methane is an important factor in global climate change, because it so effectively traps heat. As conditions warm, global research has indicated that more methane is released, which then stands to further warm the planet. Scientists call this phenomenon a positive feedback loop.

"We believe that the release of methane from the Arctic, and in particular this part of the Arctic, could impact the entire globe," Shakhova said.

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