I get a lot of notifications in my inbox daily about scientific rumblings going on in the world, but this one caught my eye this evening. Some recent NASA data in the arctic region seems to point to a huge acceleration in the melting rate of the ice — should the melting continue at its current rate, NASA scientists project that it’s only a matter of years before the arctic might be completely ice free in the summers.
An already relentless melting of the Arctic greatly accelerated this summer, a warning sign that some scientists worry could mean global warming has passed an ominous tipping point. One even speculated that summer sea ice would be gone in five years.
Greenland’s ice sheet melted nearly 19 billion tons more than the previous high mark, and the volume of Arctic sea ice at summer’s end was half what it was just four years earlier, according to new NASA satellite data obtained by The Associated Press.
The Arctic is screaming,” said Mark Serreze, senior scientist at the government’s snow and ice data center in Boulder, Colo.
Just last year, two top scientists surprised their colleagues by projecting that the Arctic sea ice was melting so rapidly that it could disappear entirely by the summer of 2040.
This week, after reviewing his own new data, NASA climate scientist Jay Zwally said: “At this rate, the Arctic Ocean could be nearly ice-free at the end of summer by 2012, much faster than previous predictions.”
So scientists in recent days have been asking themselves these questions: Was the record melt seen all over the Arctic in 2007 a blip amid relentless and steady warming? Or has everything sped up to a new climate cycle that goes beyond the worst case scenarios presented by computer models?
“The Arctic is often cited as the canary in the coal mine for climate warming,” said Zwally, who as a teenager hauled coal. “Now as a sign of climate warming, the canary has died. It is time to start getting out of the coal mines.”
The surface area of summer sea ice floating in the Arctic Ocean this summer was nearly 23 percent below the previous record. The dwindling sea ice already has affected wildlife, with 6,000 walruses coming ashore in northwest Alaska in October for the first time in recorded history. Another first: the Northwest Passage was open to navigation.
Still to be released is NASA data showing the remaining Arctic sea ice to be unusually thin, another record. That makes it more likely to melt in future summers. Combining the shrinking area covered by sea ice with the new thinness of the remaining ice, scientists calculate that the overall volume of ice is half of 2004’s total.
In addition to changes in the arctic ice, there are also many changes going on with permafrost regions in the arctic, in particular with Greenland and Alaska:
Alaska’s frozen permafrost is warming, not quite thawing yet. But temperature measurements 66 feet deep in the frozen soil rose nearly four-tenths of a degree from 2006 to 2007, according to measurements from the University of Alaska. While that may not sound like much, “it’s very significant,” said University of Alaska professor Vladimir Romanovsky.
Surface temperatures in the Arctic Ocean this summer were the highest in 77 years of record-keeping, with some places 8 degrees Fahrenheit above normal, according to research to be released Wednesday by University of Washington’s Michael Steele.
Greenland, in particular, is a significant bellwether. Most of its surface is covered by ice. If it completely melted something key scientists think would likely take centuries, not decades it could add more than 22 feet to the world’s sea level.
However, for nearly the past 30 years, the data pattern of its ice sheet melt has zigzagged. A bad year, like 2005, would be followed by a couple of lesser years.
According to that pattern, 2007 shouldn’t have been a major melt year, but it was, said Konrad Steffen, of the University of Colorado, which gathered the latest data.
“I’m quite concerned,” he said. “Now I look at 2008. Will it be even warmer than the past year?”
If you’ve followed any reports on global warming in the past few years, the main consensus with most of them is that we are really at a point of no return, something that this latest batch of data also seems to suggest.