In science, processes that feed themselves (are self-sustaining) may be called vicious cycles if there is a destructive result. In earlier posts, I reported on fears that the melting of Arctic ice and permafrost was a vicious cycle. Bad news: it’s happening faster than previously expected.

1,460 billion metric tons of organic carbon

A major new federal assessment of the Arctic region and climate change trends released on Tuesday says the world’s warming temperatures are causing permafrost to melt, which could result in the ground releasing the organic carbon it now stores — about 1,460 to 1,600 billion metric tons worth. Permafrost covers 24 percent of the land in the Northern Hemisphere, including huge swaths of Alaska, Canada, Siberia and Greenland. The Washington Post reports that “warming temperatures allow microbes within the soil to convert permafrost carbon into the greenhouse gases — carbon dioxide and methane — which can be released into the air and accelerate warming.” [The Washington Post via 538]