Going, going, gone

The North Polar ice sheet continues to recede, setting yet another record:

Sea ice extent continues to decline, and is now at 4.78 million square kilometers (1.84 million square miles), falling yet further below the record absolute minimum of 5.32 million square kilometers (2.05 million square miles) that occurred on September 20-21, 2005. -- The National Snow and Ice Data Center, Aug. 28.

Here's the map:

Caveat: this is sea ice extent, not total area coverage. Different groups measure different things. But the trend is unambiguous. The purple line is the median for a typical August.

Note also that according to the NSIDC, "the summer melt season usually begins in March and ends sometime during September." So we can expect the record to be broken several times this year before the melting ends.

Mark Serreze, who has become the top go-to ice expert at the center, has what some might call "alarmist" interpretation, as reported by Randy Boswell of the National Post:

What particularly concerns scientists is that the thawing of Arctic ice typically continues until mid-September, virtually ensuring that next summer's melt season will begin with a much-reduced base of what used to be called "permanent" ice.

The ice "is going to remember that next year," said Serreze. "Everything seems to be ahead of schedule and the models are all too slow. We're on the fast track."

The accelerated annual loss of Arctic ice prompted Serreze to predict that the entire polar region, including the North Pole, could witness a total summer melt by 2030.

That's not as dire as the worst-case scenario (all gone within 13 years) raised by some others but it is a decade sooner than the prediction of an ice-free summer by 2040, which has been the conventional wisdom for the last year or so.

Boswell's story focuses on the opening of the Northwest Passage, which is not too surprising as the National Post is a Canadian Paper, and Canadians tend to care a fair bit about such things. And for good reason, as the U.S., among other nations, does not recognize Canada's claim to the waters surrounding the Arctic Archipelago that constitute a fast shipping route across the North, one that shaves 5,000 nautical miles off the trip between Asia and Europe.

But as climatologist Andrew Weaver told me several years ago, the Northwest Passage isn't nearly as attractive as the Northeast Passage, the one that runs across Russia's north coast:

"I would be looking for a passage to open in the summer by Russia first and not one by Canada." Weaver has even taken a peak into the future with the help of an animated map of the Arctic Ocean as the ice caps melts. The first to free up is the Russian coast, with wide swathes free by 2020. By 2050, though, most of Canada's Arctic Archipelago is free as well. (Up Here, April 2001.)

A look at that NSICD map, and it's hard not to draw the same conclusion.