Heat produced by Arctic soil microbes could enhance permafrost thaw and the release of carbon to the atmosphere, according to a paper published this week in Nature Climate Change.

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 and colleagues quantified microbial heat production in 21 samples of natural organic permafrost soils collected from six sites across Greenland to investigate whether enough heat can be produced by enhanced activity to affect the rate of soil decomposition. Their model simulations reveal a feedback loop between soil temperatures and carbon decomposition that could accelerate rates of permafrost thaw and microbial heat production between 2012 and 2100.

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.