Earth Equity News

Study Says Undersea Release of Methane is Under Way. By Cornelia Dean, NYTimes, March 5, 2010. "Climate scientists have long warned that global warming could unlock vast stores of the greenhouse gas methane that are frozen into the Arctic permafrost, setting off potentially significant increases in global warming. Now researchers at the University of Alaska, Fairbanks, and elsewhere say this change is under way in a little-studied area under the sea, the East Siberian Arctic Shelf, west of the Bering Strait. Natalia Shakhova, a scientist at the university and a leader of the study, said it was too soon to say whether the findings suggest that a dangerous release of methane looms. In a telephone news conference, she said researchers were only beginning to track the movement of this methane into the atmosphere as the undersea permafrost that traps it degrades. But climate experts familiar with the new research reported in March 5 issue of the journal Science that even though it does not suggest imminent climate catastrophe, it is important because of methane's role as a greenhouse gas. Although carbon dioxide is far more abundant and persistent in the atmosphere, ton for ton atmospheric methane traps at least 25 times as much heat.

"Until recently, undersea permafrost has been little studied, but work so far shows it is already sending surprising amounts of methane into the atmosphere, Dr. Shakhova and other researchers are finding. Last year, scientists from Britain and Germany reported that they had detected plumes of methane rising from the Arctic seabed in the West Spitsbergen area, north of Scandinavia. At the time, they said they had begun their work hoping to gain data to predict future emissions and had not expected to find evidence that the process was under way. It is 'indispensable' to keep track of methane in the region, Martin Heimann of the Max Planck Institute in Germany said in a commentary accompanying the Science report. So far, Dr. Heimann wrote, methane contributions from Arctic permafrost have been 'negligible.' He added: 'But will this persist into the future under sustained warming trends? We do not know.' Dr. Shakhova…estimated that annual methane emissions from the East Siberian Arctic Shelf total about seven teragrams. (A teragram is 1.1 million tons.) By some estimates, global methane emissions total about 500 teragrams a year."