Arctic Melt Opens (Fabled) Northwest Passage
Arctic Melt Opens Northwest Passage
The famed Northwest Passage—a direct shipping route from Europe to Asia across the Arctic Ocean—is ice free for the first time since satellite records began in 1978, scientists reported Friday.
The passage is a shortcut between the Atlantic and Pacific Oceans through the Canadian Arctic. It would save valuable time and fuel for ships that now travel through the Suez Canal in Egypt or the Panama Canal in Central America.
Climate models had projected the passage would eventually open as warming temperatures melted the Arctic sea ice—but no one had predicted it would happen this soon.
"We're probably 30 years ahead of schedule in terms of the loss of the Arctic sea ice," said Mark Serreze, a senior scientist at the National Snow and Ice Data Center (NSIDC) in Boulder, Colorado.
"We're on this fast track of change."
Tipping Point?
The recording-breaking Arctic sea ice melt this summer suggests that the region is either near or has reached a so-called tipping point in the climate system, Serreze noted.
A tipping point is when the climate system reaches a threshold where gradual changes suddenly kick in to high gear, he explained.
"Are we there now? We don't know, but my guess is we've got to be darn close if we haven't hit one already," he said.
Serreze cautioned, however, against drawing conclusions from just this year alone. Natural variability in the climate system, for example, could have caused the record low.
"But it looks like the overall trend is toward declining sea ice cover," he said, "and 2007 is just setting that exclamation point."
http://news.nationalgeographic.com/n...t-passage.html
Northwest Passage
http://en.wikipedia.org/wiki/Northwest_Passage
