By Chris Mooney
Siberian craters are back in the news — apparently thanks to a Siberian Times report, full of stunning pictures, claiming that “Dozens of new craters suspected in northern Russia.”
This tends to freak us out, and not surprisingly. After all, one leading idea about the source of the mysterious craters is that these might represent explosions of methane gas into the atmosphere — liberated by melting Arctic permafrost, which is, of course, destabilizing because of global warming.
“What I think is happening here is, the permafrost has been acting as a cap or seal on the ground, through which gas can’t permeate,” says Paul Overduin, a senior scientist at the Alfred Wegener Institute in Germany who studies permafrost, of the craters. “And it reaches a particular temperature where there’s not enough ice in it to act that way anymore. And then gas can rush out.”
Here’s why this is scary: If large amounts of methane vent from the Arctic into the atmosphere, that could lead to a positive climate change feedback — still more warming, still more methane release, and so on and so on and so on. That’s because methane is not only a greenhouse gas, but a potent one at that — pound for pound, it causes much more global warming than carbon dioxide does (though, fortunately, it does not last nearly as long in the atmosphere).
However, it all really depends on how much methane is venting — and, so far, it’s not clear that it’s very much.
Continue reading at Washington Post…