Some of the top polar scientists in the world have concluded (boldface in original):
Our main conclusions so far indicate that there is a very low probability that Arctic sea ice will ever recover. As predicted by all IPCC models, Arctic sea ice is more likely to disappear in summer in the near future. However it seems like this is going to happen much sooner than models predicted, as pointed out by recent observations and data reanalysis undertaken during IPY and the Damocles Integrated Project. The entire Arctic system is evolving to a new super interglacial stage seasonally ice free, and this will have profound consequences for all the elements of the Arctic cryosphere, marine and terrestrial ecosystems and human activities. Both the atmosphere and the ocean circulation and stratification (ventilation) will also be affected.
This is what U.S. experts have been saying for a while (see NSIDC: Arctic melt passes the point of no return, “We hate to say we told you so, but we did”). Though not every scientist got the memo (see here). And this is just one in a long line of climate impacts coming up faster than the models projected (see here for a list).
But what I think is quite interesting is that this is the first time I’ve seen such leading polar scientists elaborate so bluntly the potentially dire consequences of an ice-free arctic:
This raises a critical set of issues, with many important implications potentially able to speed up melting of the Greenland ice sheet, accelerating the rise in sea levels and slowing down the world ocean conveyor belt (THC). That would also have a lot of consequences on the ocean carbon sink (Bates et al. 2006) and ocean acidification. Permafrost melting could also accelerate during rapid Arctic sea-ice loss due to an amplification of Arctic land warming 3.5 times greater than secular 21st century climate trends, as pointed out recently by Lawrence et al. (2008). This permafrost evolution would have important consequences and strong impacts on large carbon reservoirs and methane releases, either in the ocean and/or on land.
This isn’t news to CP readers (see “Tundra 4: Permafrost loss linked to Arctic sea ice loss“).
The whole IPY post has an excellent discussion of some of the underlying research and science. The International Polar Year deserves kudos for this and other blunt statements, all available here.
h/t Michael Tobis