Arctic Ocean ice cover retreated faster last month than in any previous May since satellite monitoring began more than 30 years ago, the latest sign that the polar region could be headed for another record-setting meltdown by summer’s end.
The U.S. National Snow and Ice Data Center had already warned earlier this spring that low ice volume — the result of repeated losses of thick, multi-year ice over the past decade — meant this past winter’s ice-extent recovery was superficial, due mainly to a fragile fringe of new ice that would be vulnerable to rapid deterioration once warmer temperatures set in.
And, driven by unusually hot weather in recent weeks above the Arctic Circle, the polar ice is disappearing at an unprecedented rate, reducing overall ice extent to less than that recorded in May 2007 — the year when a record-setting retreat by mid-September alarmed climatologists and northern governments.
The centre reported that across much of the Arctic, temperatures were two to five degrees Celsius above average last month.
“In May, Arctic air temperatures remained above average, and sea ice extent declined at a rapid pace,” the Colorado-based centre said in its June 8 report.
The centre pegged the retreat at an average of 68,000 square kilometres a day, noting that “this rate of loss is the highest for the month of May during the satellite record.”
Ice loss was greatest in the Bering Sea and the Sea of Okhotsk, “indicating that the ice in these areas was thin and susceptible to melt,” the centre added.
“Many polynyas, areas of open water in the ice pack, opened up in the regions north of Alaska, in the Canadian Arctic Islands, and in the Kara and Barents and Laptev seas.”
The report also highlighted recent research indicating that, along with reduced ice extent — now reliably measured by the U.S. centre through satellite tracking — harder-to-measure ice volume also appears to be on a steady decline as mature ice that had previously survived many summers is now disappearing.
“Ice extent measurements provide a long-term view of the state of Arctic sea ice, but they only show the ice surface,” the centre stated. “Total ice volume is critical to the complete picture of sea-ice decline. Numerous studies indicate that sea-ice thickness and volume have declined along with ice extent.”
The report references a new University of Washington measurement model that estimates Arctic ice-volume trends.
According to those scientists, average Arctic ice volume in May was 19,000 cubic kilometres, “the lowest May volume over the 1979 to 2010 period.”
In November, University of Manitoba polar scientist David Barber also raised concerns about the increasingly “rotten” state of the Arctic’s oldest ice and predicted ice-free summers could become the norm far sooner than 2030, as some experts have forecast.
The U.S. centre was instrumental in alerting the world in 2007 to an unprecedented summer melt of Arctic sea ice, from 14 million square kilometres that winter to about 4.3 million square kilometres by September 2007.
The past two summers have shown modest recoveries in ice extent to a late-summer minimum of about 4.7 million square kilometres (2008) and 5.4 million square kilometres (2009), still the second- and third-lowest extents since satellite measurements began in 1979.
Despite the new signs pointing to a potential record-setting retreat again this summer, the U.S. centre isn’t making any firm predictions yet.
“It is too soon,” it stated, “to say whether Arctic ice extent will reach another record low this summer — that will depend on the weather and wind conditions over the next few months.”
Earlier this month, a major international study of the polar cap concluded that the Arctic ice retreat in recent years is the worst in several millennia.
That study, involving 18 scientists from five countries and published in the journal Quaternary Science Reviews, included data from two Canadian co-authors, who interpreted historic levels of ice cover from ancient whale bones found throughout the polar region.
"The current reduction in Arctic ice cover started in the late 19th century, consistent with the rapidly warming climate, and became very pronounced over the last three decades," the study stated. "This ice loss appears to be unmatched over at least the last few thousand years and (is) unexplainable by any of the known natural variabilities."
The problem with this model is of course that if it is already so warm as to melt away ice so rapidly...it's already too late to stop it. Making energy-rich companies pay for using the energy they would have used anyway, while they in turn pay poor countries who don't have the ability to use their carbon credits (Haiti, or at least its government, will make a fortune) will accomplish nothing.
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