Alaska’s Permafrost Is Thawing<br />Starting just a few feet below the surface and extending tens or even hundreds of feet down, it contains vast amounts of carbon in organic matter — plants<br />that took carbon dioxide from the atmosphere centuries ago, died and froze before they could decompose.<br />Estimates vary on how much carbon is currently released from thawing permafrost worldwide,<br />but by one calculation emissions over the rest of the century could average about 1.5 billion tons a year, or about the same as current annual emissions from fossil-fuel burning in the United States.<br />Scientists have estimated that the process of permafrost thawing could contribute as much as 1.7 degrees Fahrenheit to global warming<br />over the next several centuries, independent of what society does to reduce emissions from burning fossil fuels and other activities.<br />Vladimir E. Ramonovsky, a permafrost researcher at the University of Alaska, Fairbanks, said<br />that temperatures at a depth of 65 feet have risen by 3 degrees Celsius (about 5.5 degrees Fahrenheit) over decades.<br />Once this ancient organic material thaws, microbes convert some of it to carbon dioxide<br />and methane, which can flow into the atmosphere and cause even more warming.
