Monday, December 15, 2008

Arctic Ice Holding On

Arctic ice extent grew normally this fall, according to reports from the NSIDC, staying about one week ahead of last year’s ice growth. It gives reason to hope that the record ice losses of 2007 were slightly ahead of the curve. That is not to say that the Arctic ice cap could come back, or that it is melting as slowly as the consensus of scientists suggests. But the ice surely will not disappear in the next five years, as a few scientists had started to imagine. We may have to wait another two or three years before the trans-Arctic shipping lanes become commercially important, and another 10 to 20 years before the first adventurer navigates a sailing ship to the North Pole.

What we have seen is that Arctic ice is just barely holding on. It stays nearly the same in years of quiet Arctic weather. But when spring or summer brings unusually warm or stormy weather to the Arctic Ocean, the sea ice can decline by 10 percent. To predict the future of Arctic ice, you would have to predict these weather events. At this point, we can only observe them.