Scientists may need to more than double their assessment of how much carbon dioxide and methane thawing Arctic permafrost will release into the atmosphere this century, according to a study published this month.

The paper, published in Nature Communications Aug. 15, said that previous estimates for how greenhouse gasses released by thawing permafrost would contribute to global climate change focused on the slow thawing of permafrost near the surface.

However, those estimates excluded the impact of thermokarst lakes that form when warming soil melts ground ice, rapidly thawing the soil beneath them and providing food for carbon-dioxide and methane-releasing bacteria.

“Thermokarst lakes provide a completely different scenario. When the lakes form, they flash-thaw these permafrost areas,” lead study author and University of Alaska Fairbanks (UAF) Water and Environmental…