Morello, Lauren. 27 Nov 2012. Large-Scale Melting of Permafrost May Be Underway. Release of CO2 is overlooked in climate models; better monitoring needed. Scientific American.
As the climate warms, thawing permafrost could have a major impact on the world’s climate, but it’s overlooked in many climate models and studies. “… large-scale thawing of permafrost may have already started,” the U.N. report says.
Permafrost covers 24% of exposed Northern Hemisphere land, contains about 1,700 billion metric tons of carbon — roughly twice the amount currently stored in the atmosphere. With Arctic temperatures warming twice as fast as the global average, scientists estimate thawing permafrost could release large amounts of carbon into the atmosphere through the end of the century with significant climate impacts. Thawing permafrost could emit 43 billion to 135 billion metric tons of carbon dioxide equivalent by 2100, and 246 billion to 415 billion metric tons of CO2 by 2200, the U.N. report says.