Ancient carbon trapped in Arctic permafrost is extremely sensitive to sunlight and, if exposed to the surface when long-frozen soils melt and collapse, can release climate-warming carbon dioxide gas into the atmosphere much faster than previously thought.
University of Michigan ecologist and aquatic biogeochemist George Kling and his colleagues studied places in Arctic Alaska where permafrost is melting and is causing the overlying land surface to collapse, forming erosional holes and landslides and exposing long-buried soils to sunlight.
The team, led by Rose Cory of the University of North Carolina, reported its findings in an article published online Feb. 11, 2013 in the Proceedings of the National Academy of Sciences. EEB graduate student Jason Dobkowski is a co-author of the paper.
"What we can say now is that regardless of how fast the thawing of the Arctic permafrost occurs, the conversion of this soil carbon to carbon dioxide and its release into the atmosphere will be faster than we previously thought," Kling said. "That means permafrost carbon is potentially a huge factor that will help determine how fast the Earth warms."
Watch for an EEB research feature coming soon.
U-M News Service press release
Caption: Professor George Kling at a landslide thermokarst on a glacial headwall near Toolik Lake, Alaska. As permafrost ice melts, the soil collapses and either creates an erosional hole in the tundra or a landslide such as this one. These features are called thermokarst failures. Photo courtesy of George Kling.