The news that the frigid Arctic tundra ringing the polar region has switched from being a net absorber, or "sink," of planet-warming greenhouse gases to a net emitter, or "source," indicates the Arctic is on the brink of further,

Increasingly frequent and severe wildfires have become a yearly concern for many Arctic communities, and a chapter of a new U.S. report involving one Canadian university—Université de Montréal—suggests that they are also having a significant impact on carbon emissions in the region.

After locking carbon dioxide in its frozen soil for millennia, the Arctic tundra is undergoing a dramatic transformation, driven by frequent wildfires that are turning it into a net source of carbon dioxide emissions,