Climate change is causing Arctic microbes to be more active and increase the thawing of permafrost

Among the best preserved kitchen-middens in the world, the Qajaa site has until now been preserved by permafrost in one of the most Northern World Heritage sites. Image: Bo Elberling

Heat produced by Arctic soil microbes, becoming more active with global warming, could increase the thawing rate of permafrost, a layer of soil or rock frozen all year round, causing the release of carbon into the atmosphere.

Researchers used simulations to show that the rates of permafrost thaw and microbial heat production could accelerate between the years of 2012 and 2100.

As global temperatures rise and permafrost thaws, the breakdown of organic material in the soil is expected to accelerate. The process by which this decomposition produces heat is not well understood.

Bo Elberling of the University of Copenhagen and colleagues quantified microbial heat production in 21 samples of natural organic permafrost soils collected from six sites across Greenland.

Their model simulations reveal a feedback loop between soil temperatures and carbon decomposition which could accelerate rates of permafrost thaw and microbial heat production.

The authors also show that this process could degrade evidence of early human activity in the Arctic, preserved in organic middens, archaeological features buried in the permafrost.