On Aug. 21, 2007, sea ice extent was 1.89 million
square miles. The magenta line shows the median
August sea ice extent based on data from 1979 to
2000. Credit: NSIDC
A vast expanse of frozen ocean as large as New Mexico disappeared from the Arctic Ocean during the past week, reducing the polar ice cap to the smallest extent ever recorded by satellite.
The Perfect Melt goes on.
Satellites recorded 4.92 million square kilometers (or 1.89 million square miles) on Aug. 21 — 131,000 square miles less than the coverage on Aug. 17 and far below the “previous lowest absolute minimum” extent of 5.32 million square kilometers or 2.05 million square miles recorded on September 20–21 of 2005, according to new figures and charts posted online Aug. 22 by the National Snow and Ice Data Center.
Arctic ice cover has now slid about 8 percent below its previous all-time record low set 25 months ago.
This unprecedented retraction — occurring with another month to go before Arctic melting season ends in late September — is bad news for ice-subsisting animals like polar bears, walrus and seals. And the absence of the natural armor provided by solid ice exposes barrier island villages like Shishmaref and Kivalina to catastrophic erosion during fall storms.
But one aspect to all this floe-grinding isn’t a complete catastrophe in itself: the fabled Northwest Passage through the Canadian Arctic islands could open to ship traffic.
Sea ice extent has dropped
below its previous record.
Credit: NSIDC
“Analysts at the Canadian Ice Service and the U.S. National Ice Center confirm that the passage is almost completely clear and that the region is more open than it has ever been since the advent of routine monitoring in 1972,” the NSIDC reported.
The NSIDC countdown site offers a detailed discussion of why the sea ice has been shrinking so fast, with explanations and graphics about the influence by cloud cover and temperature and currents.
Don’t miss the “Disappearance of old ice, 1982–2007″ animation that shows the amoeba-like gyrations and drawdown of the ice cap. This graphic illustrates why the ice cap shrink has accelerated — the thick multi-year ice has been drifting out of the Fram Strait east of Greenland.
Regarding the Northwest Passage, don’t start packing the Bayliner for your Baffin Island fishing trip just yet.
The notion that melting Arctic ice will become a dramatic boon to international shipping has become one of the most misunderstood and overstated consequences of climate change. Sorting out what will actually happen becomes even more important as the Arctic nations scramble for claims and drop flags into the abyss.
“Open water” can include plenty of ship-gouging icebergs and floes (think Titanic), sometimes sent careening by long fetches. In some ways, the newly opened Arctic may be more dangerous for shipping, at least for vessels that lack ice-strengthened hulls.
Northwest Passage has open water.
Credit: NSIDC
As scientist and former U.S. Coast Guard ice-breaker captain Lawson Brigham of the U.S. Arctic Research Commission has pointed out repeatedly at forums, it will be many decades before shippers will be able to rely on open water seasons enough to actually schedule over-the-pole trips between Atlantic and Pacific. In most scenarios, the Northwest Passage (which fascinates world media) is likely to be the very last portion of the Arctic to go ice free in summer.
As a result, most new shipping opportunities will be within the Arctic Ocean, Brigham has said, focused on resource extraction and resupply, or forays along the northern Russian coast.
Brigham warns that competing claims in the Arctic could trigger a new “cold war” in an essay “Thinking About the Arctic’s Future: Scenarios for 2040,” published the September-October issue of the Futurist .