"Thawing Permafrost: the Arctic's Slow, Giant Carbon Release"

"As the Arctic melts and organic matter decays, vast stores of carbon in the permafrost will be released triggering an unstoppable feedback system."

"Permafrost—a vast, frozen subsurface layer of soil—covers nearly a quarter of the land in the northern hemisphere. It contains centuries worth of carbon in the form of plants that have died since the last ice age but remained frozen rather than decomposing.

Now scientists are learning that the "perma" part of its name may no longer be accurate.

As the Arctic heats up at a rate twice that of the rest of the globe and as sea ice and glaciers turn to water, the permafrost is also thawing. A recent review article in the journal Nature found that as the unfrozen organic matter decays, vast stores of carbon in the permafrost could be released into the atmosphere. This will trigger an irreversible feedback system and nullify existing calculations of just how much carbon humans can burn and keep the globe within a relatively safe degree of warming."

Sabrina Shankman reports for InsideClimate News April 23, 2015.

Source: InsideClimate News, 04/27/2015