the evidence mounts:
A new seven-year study of the Arctic's shrinking sea ice - which is headed for another above-average melt this summer - concludes that the polar cap is not only losing vast swathes of surface area but also experiencing a "drastic thinning" likely to reinforce the overall retreat.
The study, headed by University of Alberta ice expert Christian Haas, found reductions of ice thickness in the central Arctic Ocean of up 50 per cent between 2001 and 2007, as well as widespread replacement of heavier, older ice near the North Pole with weaker first-year ice.
"The regime shift to younger and thinner ice could soon result in an ice-free North Pole during summer," says the study, to be published in the fall by the U.S. journal Geophysical Research Letters but obtained this week by Canwest News Service.
"Reduced ice thickness in Arctic Transpolar Drift favours rapid ice retreat" - was co-authored by a six-member team of researchers from Europe and North America and completed while Haas was with the Alfred Wegener Institute for Polar and Marine Research in Germany.
Travelling over several seasons aboard the German icebreaker RV Polarstern, the team's key findings were produced by aerial surveys in which electromagnetic instruments carried by helicopter measured ice thickness at scores of sample sites throughout the central polar region between Canada and Russia.
The Transpolar Drift describes the general flow of Arctic Ocean ice from eastern Siberia past the North Pole toward Greenland, a conveyor belt of ice also fed by the clockwise-flowing Beaufort Gyre north of Alaska and the Yukon.
"Clearly, the thinner ice cover favours a stronger areal retreat of the ice during summer," the researchers conclude, noting that their study "points to the possibility of further rapid reductions once that vast uniform region has thinned further below certain thresholds."
Im sure it's all just due to sun spots, cyclical variation or Al Gore will a big blowtorch. The saddest part, they actually think they're the clever ones.