The ice sheet is melting and permafrost is thawing. What's happening in Greenland will speed up climate change across the world.
Set aside the politics. If by some miracle we turned off carbon emissions immediately, how would the climate respond?
Global warming is changing the movement of carbon within northern ecosystems to the point where the Arctic could become a net source, rather than sink, of greenhouse gas emissions.
Scientists are studying how carbon-rich permafrost known as yedoma acts much like frozen vegetables to hungry microbes -- and is becoming an additional source of heat-trapping gases.