Now a large “unknown unknown” has reared its very ugly head. The oceans of the world routinely release methane, from a variety of processes, as do the soils. A new paper, published today in the journal Science, reports that the East Siberian Arctic Ice Shelf, a 2 million square mile area of the Arctic Sea north of Siberia, is releasing as much methane as the rest of the world’s oceans combined. According to Dr. Natalia Shakhova, lead author of the paper, the release is about 7 teragams, or about 7 million tonnes, of methane annually.

Dr. Shakhova continues: “Our concern is that the subsea permafrost has been showing signs of destabilization already,” she said. “If it further destabilizes, the methane emissions may not be teragrams, it would be significantly larger.” The release of less than 1% of the methane trapped in this one area could lead to a tripling or more in the methane in the Earth’s atmosphere, strongly contributing to global warming.

Such a release would also cause heightened warming in its local region, accelerating methane releases from this shelf, and likely increasing permafrost degradation right across this very sensitive area. This would probably put the Earth’s climate firmly into runaway climate change, and might even cause abrupt climate change – a sudden temperature increase of several degrees Celsius in just a few years.

It’s worth reading the press release from the US National Science Federation (NSF) announcing the work. It calls the methane release “alarming”, and even mentions abrupt climate change as a possible outcome. Methane levels in “hotspots” are hundreds or a thousand times more than background levels, and the entire region has a “bubble” of elevated atmospheric methane. While theoretically possible, it’s hard to believe that these releases have been going on for a long time. This is just one of the determinations that urgently need to be made. However, the initial implications of this work are very bad.

Links (which have further links):

- The UN Environmental Program ice shelf map and NSF press release mentioned above.

- Climate Progress, which is usually on the optimistic side, has the best summary I’ve seen so far, with strong links, a video of the lead scientist on the issue speaking, and useful comments as well. (As much to capture the zeitgeist as for specific information.)

- The New York Times has a low-key article that summarizes, and somewhat downplays the results.

- Andy Revkin of the Times’ flawed Dot Earth blog emphasizes only the comments of scientists who call this a preliminary result.

* A half-humorous reference to the REM song, “It’s The End Of The World As We Know It (And I Feel Fine)“.