A new study projects that half the world’s land-based permafrost will vanish by mid-century on our current greenhouse gas emissions path, turning today’s Arctic carbon into a huge carbon source by the 2020s, at which time the North Pole is expected to be largely ice-free. The thaw and decay of permafrost carbon is irreversible.

What would that mean?

It means we’ll have to reduce our fossil fuel emissions a lot more if we are going to manage to control global warming and prevent catastrophic impacts of climate change.

This is the bombshell news just out in a major new study published in Tellus by the US National Ocean and Atmospheric Administration (NOAA) and the National Snow and Ice Data Center (NSIDC).

As reported in Climate Progress: ‘The carbon is locked in a freezer in the part of the planet warming up the fastest (see “Tundra 4: Permafrost loss linked to Arctic sea ice loss“). Countless studies make clear that global warming will release vast quantities of GHGs into the atmosphere this decade.

‘. . . The people out there who think R&D or an energy quest is going to stop us from multiple catastrophes are deluding themselves and others. We need to start aggressive mitigation now as every major independent study concludes.’

Read the whole (depressingly shocking) news story at the well-respected Climate Progress website: NSIDC bombshell: Thawing permafrost feedback will turn Arctic from carbon sink to source in the 2020s, releasing 100 billion tons of carbon by 2100: Study underestimates impacts with conservative assumptions, 17 February 2011.