Fires, intensified by climate change, release carbon trapped in soil and plants. More frequent infernos have now transformed the tundra into a net source of carbon dioxide emissions. It’s a dramatic shift for the Arctic, and one that will make the planet even hotter.

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.