Temperatures are warming faster in the Arctic than anywhere else on Earth, at twice the rate of the global average. In northern Canada, it hasn’t been this warm in at least 44,000 years, according to our best estimates.
That means weird things are starting to happen. 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.
Katey Walter Anthony, of the University of Alaska Fairbanks, has been measuring methane seeps in Arctic lakes in Alaska, Canada, and Russia for about a decade. Her estimates show that global atmospheric methane concentrations could increase tenfold in the coming years. She explained her research in a 2010 video, in which she ignited a few of the bubbles, resulting in an impressive ball of flame:
I spoke with her colleague, Vladimir Romanovsky, who was a co-author on the study that quantified the amount of carbon that may be released from permafrost this century. Romanovsky believes the Siberian holes are an example of a new type of Arctic landform that has never been seen before.
“The warming has started to decompose the gas hydrates,” Romanovsky told Slate. “The pressure increased so high that it actually erupted the material out of the hole.” The Siberian craters are found in a primary area of industrial natural gas extraction. “It’s still much more questions than answers at this point,” he said. “For all my 40 years of studying permafrost, I’ve never read about these kinds of things. Nobody knows any examples of these happening in the past.”
Could the same thing happen in Alaska? Romanovsky says yes. “At this point, I would say it is possible. There are several candidate places in Alaska or in Northwest Canada.”
Charles Miller, a permafrost scientist with NASA’s Jet Propulsion Laboratory, disagrees slightly with Romanovsky. According to Miller, whose work has focused on collecting aircraft measurements of the amount of methane currently being released from North American permafrost, the Siberian holes are more likely to be formed as a result of a more well-established landform called a pingo. “If one looks back at the older [satellite] images of the same locations, these pingos were at the exact same locations.”
But Miller does agree they could happen in Alaska. On his flights over the Alaskan and Canadian Arctic, Miller says the landscape is littered with pingos. “In principle, the same mechanisms [as the exploding Siberian holes] might be able to operate in Alaska.”