Death Spiral Watch: Experts Warn 'Near Ice-Free Arctic in Summer' in a Decade if Trends Continue
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I do realize that the above sounds ‘alarmist’ and I’ve heard such criticism more than once before but I believe it’s my obligation to make sure that this message is heard by the policymakers and general public.
Maslowski did not make a new timing prediction, but instead directed me to a recent article he was lead author on, “ The Future of Arctic Sea Ice,” in Annual Review of Earth and Planetary Sciences.
That article estimated a loss of 1,120 cubic kilometres per year from 1996 to 2007, quite close to the recently reported CryoSat-2 measurements. It continued:
Given the estimated trend and the volume estimate for October–November of 2007 at less than 9,000 km3 ( Kwok et al. 2009), one can project that at this rate it would take only 9 more years or until 2016 ± 3 years to reach a nearly ice-free Arctic Ocean in summer. Regardless of high uncertainty associated with such an estimate, it does provide a lower bound of the time range for projections of seasonal sea ice cover.
This is the same estimate Maslowski made in 2006, although he has couched it more conservatively here and has explained that he wouldn’t be surprised if some summer ice lingers above Greenland and Eastern Canada into the 2020s. That’s why he uses the term “nearly ice-free.”
What’s interesting is that the volume trend has in fact continued according to PIOMAS and CryoSat-2. Many other experts are warning that we have effectively passed the point of no return and nearly ice-free are imminent. Fen Montaigne, senior editor of Yale e360, reports:
Peter Wadhams, who heads the Polar Ocean Physics Group at the University of Cambridge and who has been measuring Arctic Ocean ice thickness from British Navy submarines, says that earlier calculations about Arctic sea ice loss have grossly underestimated how rapidly the ice is disappearing. He believes that the Arctic is likely to become ice-free before 2020 and possibly as early as 2015 or 2016 — decades ahead of projections made just a few years ago.
Mark Drinkwater, mission scientist for the European Space Agency’s CryoSat satellite and the agency’s senior advisor on polar regions, said he and his colleagues have been taken aback by the swiftness of Arctic sea ice retreat in the last 5 years. “If this rate of melting [in 2012] is sustained in 2013, we are staring down the barrel and looking at a summer Arctic which is potentially free of sea ice within this decade,” Drinkwater said in an e-mail interview.
Wadhams told the BBC how much warming is accelerated by just replacing the reflective white ice with the more absorptive open ocean:
Prof Wadhams calculates that this increased absorption of the sun’s rays is “the equivalent of about 20 years of additional CO2 being added by man”.
The Cambridge University expert says that the Arctic ice cap is “heading for oblivion.”
Not every expert thinks the Arctic will be necessarily be nearly ice free by 2020. And Dr Seymour Laxon who has been working on the CryoSat-2 data said this of the 2020 projection:
Laxon urged caution, saying: “First, this is based on preliminary studies of CryoSat figures, so we should take care before rushing to conclusions. In addition, the current rate of ice volume decline could change.” Nevertheless, experts say computer models indicate rates of ice volume decline are only likely to increase over the next decade.
But whenever the nearly ice free conditions occur (and I’ve long been in the camp that says it’ll be by 2020), those who think we have not effectively crossed a point of no return — those who think we are not in a death spiral — are not paying attention to the thickness and volume analysis. As Yale e360 reported: