Last summer, giant mysterious craters discovered by reindeer herders in a remote section of northern Siberia captured the world’s attention. Upon closer inspection, it was obvious these craters formed recently with some explosive force behind them. Since then, there have been further scientific excursions to the craters, including this one in November:
According to measurements made by Russian scientists, methane concentration at the bottom of one of the holes was thousands of times higher than in the regular atmosphere. A more thorough recent expedition identified “dozens” of new holes, all of which apparently formed in the last year or two.
The Siberian holes draw into question the near-term stability of Arctic permafrost, which traps enough carbon, if fully unleashed, to double atmospheric concentrations and potentially push global warming into a frightening new phase. Scientists are quite certain it will take at least a century for that to happen in a worst-case scenario, but it’s clear that the release has already begun.
A recent study estimated continued warming would produce an additional 35-205 billon tons of carbon emissions (about 2-10 percent of current global totals) from permafrost by 2100. The wide range reflects how little we still know about the response of permafrost to increased temperatures. Since the permafrost thaw is already in progress, it could be difficult to slow down: Even a sharp cutback in emissions from cities and cars may only be able to cut those numbers in half. With the atmosphere only able to hold another 400 billion tons or so before we’re committed to a rise in global temperatures of more than 2 degree Celsius, the point after which “dangerous” impacts become much more likely.
