New Methane Releases Discovered in Siberian Arctic, Study Says

Methane, a gas with at least 25 times the heat-trapping power of carbon dioxide, is leaking through a layer of thawing, sub-sea permafrost that has long acted as a barrier over a reservoir of methane in the East Siberian Arctic, according to a new study. Further destabilization of the permafrost barrier on the Arctic shelf “could trigger abrupt climate warming,” scientists at the University of Alaska Fairbanks International Arctic Research Center said. Sizable methane leaks have recently been discovered in other Arctic regions, and the University of Alaska researchers took air and water measurements of methane at 5,000 sites from 2003 to 2008 along the East Siberian Arctic Shelf. The scientists say that roughly 7 to 11 million tons of methane are now leaking through the shelf in East Siberia annually, a small amount compared to man-made carbon-dioxide levels released worldwide. Levels of methane in the atmosphere above the Arctic have reached 1.85 parts per million, nearly three times the global average, and methane levels in East Siberia are 2 parts per million or more, said Natalia Shakhova, a researcher at the University of Fairbanks and lead author of the study, which was published in the journal Science. “Our concern is that the sub-sea has been showing signs of destabilization already,” Shakhova told reporters. “It if further destabilizes, the methane emissions… would be significantly larger.” The methane was formed by the decay of plant matter that accumulated in the soil of the Arctic shelf when it was peatland above sea level.