Arctic sea ice will probably not recover

A long, scary piece from the International Polar Year. The boldface is theirs: As predicted by all IPCC models, Arctic sea ice will most likely disappear during summers 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.

…Unprecedented events have been reported during the past 20 years in the Arctic Ocean, mostly related to the Arctic sea ice summer minimum extent that retreated in September 2007, far beyond previous extreme minimum records. This is the first clear evidence of a phenomenon of importance on a planetary scale, forced by global warming, mainly caused initially by an Earth energy imbalance due to greenhouse gas concentrations increasing in the atmosphere.

…. Our main conclusions so far indicates 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 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….

The first polar year of Damocles (2007) was mainly characterized and highlighted by the transpolar drift of the French vessel Tara (September 2006-January 2008), 115 years after the Norwegian Fram expedition with Fridtjof Nansen at the helm. Tara drifted along the transpolar drift in an amazing 15 months (500 days) compared to 3 years for the Fram 115 years ago.