Which raises the question: Well, how dangerous is the methane that is emerging from the Arctic? Is it just blowing holes in the permafrost, or does it presage global atmospheric doom?
It's not a small volume of methane, after all, and we know that methane in the short term is a far more potent greenhouse gas than CO2-- about 30x more potent, to be exact. So the concept of a "methane time bomb" that will set off the greatly feared runaway global warming seems plausible at a glance.
But look closer, says RealClimate, with lots and lots of data. (From last week.) They conclude:
...the future of Earth’s climate in this century and beyond will be determined mostly by the fossil fuel industry, and not by Arctic methane. We should keep our eyes on the ball.