the big thaw
As the climate continues to warm, the permanently frozen ground underneath much of Alaska is starting to thaw. While the loss of permafrost would obviously have big consequences for the state's population, wildlife, and infrastructure, perhaps even more alarmingly, it would also have a huge impact on the already increasing global temperature, The New York Times reported Wednesday:
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. Worldwide, permafrost is thought to contain about twice as much carbon as is currently in the atmosphere.
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. 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. [The New York Times]
The complete thaw of the Arctic's "always-frozen ground" is estimated to be millennia away, but already the melting ground is believed to be contributing to rising carbon emissions in the region. One calculation estimates that right now, thawing permafrost worldwide emits about 1.5 billion tons of fossil fuel annually, which the Times noted is "slightly more than the United States emits from fossil-fuel burning."
“There's a massive amount of carbon that's in the ground, that's built up slowly over thousands and thousands of years," said Max Holmes, a senior scientist at the Woods Hole Research Center studying Alaska's permafrost melt. "It's been in a freezer, and that freezer is now turning into a refrigerator."
Read more on the alarming thaw at The New York Times.