Alaska’s Permafrost Is Thawing
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
that took carbon dioxide from the atmosphere centuries ago, died and froze before they could decompose.
Estimates vary on how much carbon is currently released from thawing permafrost worldwide,
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.
Scientists have estimated that the process of permafrost thawing could contribute as much as 1.7 degrees Fahrenheit to global warming
over the next several centuries, independent of what society does to reduce emissions from burning fossil fuels and other activities.
Vladimir E. Ramonovsky, a permafrost researcher at the University of Alaska, Fairbanks, said
that temperatures at a depth of 65 feet have risen by 3 degrees Celsius (about 5.5 degrees Fahrenheit) over decades.
Once this ancient organic material thaws, microbes convert some of it to carbon dioxide
and methane, which can flow into the atmosphere and cause even more warming.