A new study published in the 5 March issue of Science magazine shows that a long warned of climate change phenomenon is now underway. Climate scientists have been saying for some time that global warming could enable the release of vast stores of the greenhouse gas methane that are frozen into the Arctic permafrost, which would in turn further provide significant increases in global warming.
The study, published by researchers at the University of Alaska, Fairbanks, and elsewhere, say this phenomenon is occurring under the sea in the East Siberian Arctic Shelf, which is west of the Bering Strait.
While climate experts say this does not suggest imminent climate catastrophe, it is important because of methane’s role as a greenhouse gas. While carbon dioxide is far more abundant and remains in the atmosphere for a much longer period than methane, atmospheric methane traps at least 25 times as much heat.
Atmospheric concentrations of methane have more than doubled since pre-industrial times, and most of it comes from human activities such as energy production, raising cattle and rice cultivation. But about 40 percent of atmospheric methane is natural, including the decomposition of organic materials in wetlands and frozen wetlands like permafrost.
Dr. Shakhova, the head researcher in the study, said that permafrost in the East Siberian Arctic Shelf, which is peat land that flooded as sea levels rose after the last ice age, is degrading in part because river runoff that feeds the Arctic Ocean is warmer than in the past.
According to Dr. Shakhova, atmospheric levels of methane over the Arctic are 1.85 parts per million, almost three times as high as the global average of 0.6 or 0.7 parts per million. Concentrations over the East Siberian Arctic Shelf are 2 parts per million or higher. For more information, read the Planet Ark story here: http://planetark.org/wen/57021. The New York Times covers this story at: www.nytimes.com/2010/03/05/science/earth/05methane.html?hpw.
source: Fishlink Sublegals