Some permafrost might soak up methane as climate warms

Talk of a warming planet often focuses on places that are cold. Glaciers shrink and raise sea level. Arctic sea ice dwindles, opening an actual northwest passage in the summer. And permafrost thaws, pulling vast amounts of organic matter out of the freezer to spoil and add to the greenhouse gases in the atmosphere. Lots of research has focused on organic-rich permafrost and the amount of carbon dioxide and methane it could produce as microbes break down all that food.

But that’s only a slice of the world’s permafrost area. The rest is more like frozen dirt than frozen peat, with a much lower carbon content. A team of researchers led by Princeton’s Chui Yim Lau and Brandon Stackhouse traveled to Axel Heiberg Island in the Canadian Arctic to see what kind of microbes they could find in the carbon-poor permafrost, and to find out how they might respond to warmer temperatures.

The researchers periodically placed special sampling chambers down on the ground and measured the changes in methane inside over a few minutes or hours. If microbes were busy producing methane, it would accumulate inside the chamber at some rate. In this case, however, methane inside the chamber decreased—a phenomenon attributed to methane-munching bacteria that have occasionally been observed at other permafrost study sites.