Lakeland burp, greenhouse threat

Siberians lakes are "burping" up five times as much methane as scientists previously estimated. Katey Walter of the University of Alaska Fairbanks and colleagues have made the first accurate estimates of emissions of methane from frozen bubbles of the gas trapped in lakes across the Siberian permafrost. A unique type of permafrost, yedoma, which contains an estimated 500 gigatons of carbon, largely in the form of ancient dead plant material, which has been locked up since the end of the last ice age. Now, it is being released into the bottom of lakes, providing microbes with a banquet from which they burp out methane as a byproduct of decomposition, Walter says. "We realized that our previous estimates were missing a very large and important component of lake emissions," she adds, the emissions could provide a positive greenhouse gas feedback loop. As temperatures rise, so more yedoma melts into the lakes, giving the microbes more to feed on and resulting in an even bigger burp.