Archive for Wednesday, December 12, 2007

New NASA data: Arctic melting accelerated in summer

December 12, 2007

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An iceberg melts off Ammassalik Island in Eastern Green-land in this file photo from July. A record amount of Greenland's ice sheet melted this summer, U.S. scientists are reporting this week in an ominous new sign of global warming.

An iceberg melts off Ammassalik Island in Eastern Green-land in this file photo from July. A record amount of Greenland's ice sheet melted this summer, U.S. scientists are reporting this week in an ominous new sign of global warming.

— 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."

It is the burning of coal, oil and other fossil fuels that produces carbon dioxide and other greenhouse gases, responsible for manmade global warming. For the past several days, government diplomats have been debating in Bali, Indonesia, the outlines of a new climate treaty calling for tougher limits on these gases.

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.

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 today. 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.

¢ 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.

Comments

asiansensation 7 years, 6 months ago

We can possibly slow it down but no stop it at all. But judging by how the world consumes so much and uses so much energy, we're doomed. We're going to begin having shorter winters and longer summers. Get used to it.

pomegranate 7 years, 6 months ago

You can't stop Mother Nature. Of course there is global warming. There has been global warming and cooling on this planet for eons.
I certainly do believe in protecting the environment. We recycle lots of stuff, and go green when we can.
We do use fuel(gasoline) and probably will not stop.
Unfortunately we have a gas powered mower, actually 2, a riding and a walk-behind. We probably do drive somewhat less now that gas is so expensive, and save many errands for one trip.

just_another_bozo_on_this_bus 7 years, 6 months ago

"Of course there is global warming. There has been global warming and cooling on this planet for eons. "

But the modern human race has not been on the planet, numbering in the billions, for eons. We and our civilizations have evolved while the climate has had largely stable characteristics, not the wide swings that folks like you want to point out to make the false claim that global warming is "purely natural."

Sure, some of the very earliest homo sapiens survived the last ice age (most lived in regions unaffected by it,) but that was a very small number of people who survived as gatherers and hunter. Without continued stable climate conditions, millions, if not billions, of the human race are doomed to a grim existence, and likely an even grimmer demise. The rest of the world's species are equally vulnerable.

Eventually, sh*tting in your own backyard has consequences.

just_another_bozo_on_this_bus 7 years, 6 months ago

"Ice melts more in the Summer?"

You are truly an inspiration, Dolly, where every day is a celebration of ignorance.

toefungus 7 years, 6 months ago

I propose Al Gore stop using his private jet and rent out his home to 20 people.

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