In northern Alaska, Dr. Romanovsky said, permafrost is warming rapidly but is still quite cold. In the central part of the state, much of it is hovering just below the freezing point and may be no more than a decade or two from widespread thawing.
The permafrost carbon thus represents a dangerous amplifying feedback or vicious cycle whereby warming leads to accelerated emissions, which leads to further warming.
That's especially true since sea ice loss in the Arctic is happening faster than every major climate model projected — and accelerated Arctic warming and permafrost loss was linked to ice loss in a 2008 study by leading tundra experts.
We find that simulated western Arctic land warming trends during rapid sea ice loss are 3.5 times greater than secular 21st century climate-change trends.
A troubling trend has emerged recently: Wildfires are increasing across much of the north, and early research suggests that extensive burning could lead to a more rapid thaw of permafrost.