The tundra and boreal forest at the top of the world, including in Alaska, Siberia, and Northern Canada, have huge amounts of carbon locked in their soil, including much more than is already contained in the atmosphere.
Release of a relatively small fraction of it could dramatically speed up climate change. Researchers know that permafrost, soil frozen year round, is thawing, releasing previously-sequestered carbon. And it appears that boreal forest fires are becoming more common and more intense, with the same possible effect.
But warming in the Arctic—where temperatures are rising three times faster than elsewhere—is also increasing vegetation growth in some areas, soaking up additional carbon. Scientists want to know which will win out: uptake or release. And, if carbon release overtakes uptake, they want to know how much carbon might eventually be added to the atmosphere and how quickly.
Two teams are working to answer different facets of this question. The upshot of both branches of work is that new studies are confirming that there is great concern about carbon being lost to the atmosphere from Arctic soils.