Monday, May 19, 2008

The Arctic is Screaming

Nothing that those who are paying attention shouldn't already know, but Wired has a good rundown of just how big this summer's record melt truly was, and some of the implications going forward from that.

"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."

. . .

What happens in the Arctic has implications for the rest of the world. Faster melting there means eventual sea level rise and more immediate changes in winter weather because of less sea ice.

In the United States, a weakened Arctic blast moving south to collide with moist air from the Gulf of Mexico can mean less rain and snow in some areas, including the drought-stricken Southeast, said Michael MacCracken, a former federal climate scientist who now heads the nonprofit Climate Institute. Some regions, like Colorado, would likely get extra rain or snow.

More than 18 scientists told the AP that they were surprised by the level of ice melt this year.

"I don't pay much attention to one year ... but this year the change is so big, particularly in the Arctic sea ice, that you've got to stop and say, 'What is going on here?' You can't look away from what's happening here," said Waleed Abdalati, NASA's chief of cyrospheric sciences. "This is going to be a watershed year."

2007 shattered records for Arctic melt in the following ways:

- 552 billion tons of ice melted this summer from the Greenland ice sheet, according to preliminary satellite data to be released by NASA Wednesday. That's 15 percent more than the annual average summer melt, beating 2005's record.

- A record amount of surface ice was lost over Greenland this year, 12 percent more than the previous worst year, 2005, according to data the University of Colorado released Monday. That's nearly quadruple the amount that melted just 15 years ago. It's an amount of water that could cover Washington, D.C., a half-mile deep, researchers calculated.

- 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.

- 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.

. . .

Melting of sea ice and Greenland's ice sheets also alarms scientists because they become part of a troubling spiral.

White sea ice reflects about 80 percent of the sun's heat off Earth, NASA's Zwally said. When there is no sea ice, about 90 percent of the heat goes into the ocean which then warms everything else up. Warmer oceans then lead to more melting.

"That feedback is the key to why the models predict that the Arctic warming is going to be faster," Zwally said. "It's getting even worse than the models predicted."


2007 may indicate that we've reached the tipping point so far as Arctic ice melt is concerned, and an ice-free Arctic may happen much earlier than anyone previously thought.

Scientists in the US have presented one of the most dramatic forecasts yet for the disappearance of Arctic sea ice.

Their latest modelling studies indicate northern polar waters could be ice-free in summers within just 5-6 years.


And the real kicker is that they never even included the watershed year this year in their model,

"Our projection of 2013 for the removal of ice in summer is not accounting for the last two minima, in 2005 and 2007," the researcher from the Naval Postgraduate School, Monterey, California, explained to the BBC.


As noted later in the BBC article and touched on above, one of the reasons for the more rapid melting being forecast is that the ice is thinning more rapidly than it's shrinking, making the remaining slab more easily melted in future summers.

"The Arctic is screaming," said Mark Serreze, senior scientist at the government's snow and ice data center in Boulder, Colo.


Will anyone listen?