Methane: A menace surfaces

Abstract

The arctic permafrost is thawing, releasing organic matter that was frozen in the ground into the bottoms of lakes. This organic matter feeds microbes that produce methane, which in turn escapes to the atmosphere. Permafrost, a rich source of organic carbon, covers 20% of the earth's land surface, and one third to one half of permafrost is now within 1.0°C to 3°C of thawing. New estimates indicate that by 2100, thawing permafrost could boost emissions of methane - a greenhouse gas that's 25 times more potent than carbon dioxide - by 20 to 40 percent beyond what would be produced by all natural and man-made sources. As a result, the earth's mean annual temperature could rise by an additional 0.32°C, further upsetting weather patterns and sea level. © 2011 American Institute of Physics.