There is a kind of climate change, though, that would be far more immediate in its impact. Abrupt climate change (Wikipedia entry here) is a sudden increase of anywhere from 2C to, perhaps, 10C of warming – that’s 3F to 16F – in about one to three years. Even at the low end, abrupt climate change would disrupt rainfall and change temperatures so much that getting the harvest in at today’s levels would be impossible, and widespread starvation would be almost impossible to avoid. Wars and more or less widespread breakdowns of order would probably ensue. At the higher end of the scale, the impact would be many times worse.

Unfortunately, ice core records seem to show abrupt climate changes of about 4C to 10C occurring about 11,000 and 22,000 years ago. The reason for the warming is disputed, and may have to do with the sudden release into the environment of CO2 and methane that had previously stored in permafrost. The idea is that gradual warming caused this stored carbon to quickly erupt in a kind of chain reaction of warming that was local at first, quickly becoming global.

We have a potential “time bomb” of this type today in the yedoma, a region of permafrost that has huge amounts of carbon stored in it, and that may not be as “perma” as we hope . Another candidate is a sudden “burp” of carbon stored deep in seawater. or of methane clathrates that are currently frozen under frigid waters.

We know that the previous abrupt climate change events occurred even without the human-caused pressure of greenhouse gas emissions that’s the main cause of the warming we’re seeing today. So, with rapid warming already underway, abrupt climate change now should be urgently studied. This research would probably tell us a lot about today’s ongoing climate change, and the odds that it might be runaway – even if not actually abrupt – as well.

Abrupt climate change, though, is what’s called a HILF – a high-impact, low-frequency event, also called a “black swan“. The 9/11 terrorist attacks of 2001 were a HILF, as was the 2008 financial crisis. HILFs, almost by definition, tend not to get much attention until they actually occur.

With even the most seemingly clear conclusions of climate science being disputed, though – at least in the US – it seems highly unlikely that the study and preparations that would do so much to help will be undertaken until after it’s too late.

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)“.