It’s official. A frozen habitat as large as Argentina — an area 1.5 times the size of Alaska — has disappeared from the summer Arctic world.
The Arctic Ocean pack likely bottomed out on Sept. 16 with the smallest ice extent and greatest reach of open water in modern history. The slow winter refreeze appears to have begun — although a full recovery of the planet’s air conditioner from 2007’s huge decline isn’t likely.
Left image shows 2007. Right image shows previous record
in 2005. Purple line shows 1979-2000 average.
See larger image at NSIDC
Source: NSIDC
How low did it go? The area with at least 15 percent ice cover retreated to 1.59 million square miles — about 22.5 percent less than the previous all-time minimum of 2.05 million square miles observed two Septembers ago.
“The minimum for 2007 shatters the previous five-day minimum set on September 20–21, 2005, by 1.19 million square kilometers (460,000 square miles), roughly the size of Texas and California combined, or nearly five United Kingdoms,” the National Snow and Ice Data Center reported in its latest fall ice dispatch.
If that comparison strikes you as startling, consider this: Between 1979 and 2000, the Arctic ice cover shrank to an average of 2.6 million square miles each year on about Sept. 12. The difference between this long-term average minimum and this week’s ice extent is stupendous.
The Arctic has lost a habitat as large as California, Alaska and 10 United Kingdoms combined, according to the NSIDC’s calculations. Imagine Argentina dissolved into slush, and you get a sense of the scale.
Over the week, the ice extent changed little. Calculations posted online on Sept. 20 suggested that the ice pack grew an additional 19,000 square miles, an area comparable to Massachusetts and Connecticut combined. The Northwest Passage, the fabled shipping route through the Canadian Arctic islands, was starting to refreeze after opening wide for the first time in modern times.
“It is still possible that ice extent could fall again, slightly, because of either further melting or a contraction in the area of the pack due to the motion of the ice,” the NSIDC said. “However, we have now seen five days of little change or slight gains in extent, so that seems unlikely at this time.”
This frozen surface serves as the essential hunting platform and resting place for thousands of marine mammals like polar bears, walrus and seals. With so much of the basic summer habitat destroyed, setting the stage for a much reduced winter ice cover, polar bears and other ice-dependent animals will almost certainly find it much harder to find enough to eat.
Satellite mosiac of the Arctic Ocean in early
Sept. 2007, clearly showing the most direct
route of the Northwest Passage open (orange line)
and the Northeast passage only partially blocked (blue line).
The dark gray colour represents the ice-free areas, while
green represents areas with sea ice.
Credits: European Space Agency
Since last winter, Arctic ice has been disappearing faster than climate models predicted surprising even the most pessimistic climate scientists. A new NOAA study compared models with observations and concluded the ice free Arctic could be about 30 years off. Other federal scientists reported that most polar bears — including all Alaska populations — would be gone by mid-century.
The retreat of the polar ice cap also poses heartbreaking problems for the people of Alaska villages like Shishmaref and Kivalina. With a fetch of open water stretching 1,000 miles or more, storms can build exceptionally big surf that consumes the barrier islands beneath village homes, tank farms, schools and roads. Lack of thick multi-year ice makes hunting less predictable and more dangerous.
Last week, an intense fall storm damaged the sea wall in Kivalina, and most villagers evacuated to other communities. People returned home over the weekend
But the season of fall storms has only just begun — and the protective ice that once protected barrier island villages from the year’s worst weather now floats hundreds of miles further north than it ever has before.
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