Current melting of Greenland's ice mimicks 1920s-1940s event
PhyOrg.com ^ | 2007-12-10 | Earle Holland

Two researchers spent months scouring through old expedition logs and reports, and reviewing 70-year-old maps and photos before making a surprising discovery. They found that the effects of the current warming and melting of Greenland 's glaciers that has alarmed the world's climate scientists occurred in the decades following an abrupt warming in the 1920s.

Their evidence reinforces the belief that glaciers and other bodies of ice are exquisitely hyper-sensitive to climate change and bolsters the concern that rising temperatures will speed the demise of that island's ice fields, hastening sea level rise.

The work, reported at this week's annual meeting of the American Geophysical Union in San Francisco , may help to discount critics' notion that the melting of Greenland 's glaciers is merely an isolated, regional event.

They recently recognized from using weather station records from the past century that temperatures in Greenland had warmed in the 1920s at rates equivalent to the recent past. But they hadn't confirmed that the island's glaciers responded to that earlier warming, until now.

“What's novel about this is that we found a wealth of information from low-tech sources that has been overlooked by most researchers,” explained Jason Box, an associate professor of geography at Ohio State University and a researcher with the Byrd Polar Research Center. Many researchers, he says, rely heavily on information from satellites and other modern sources.

Undergraduate student Adam Herrington, co-author on this paper and a student in the School of Earth Sciences, spent weeks in the university's libraries and archives, scouring the faded, dusty books that contained the logs of early scientific expeditions, looking primarily for photos and maps of several of Greenland 's key glaciers.

“I must have paged through more than a hundred such volumes to get the data we needed for this study,” Herrington said.

They concentrated on three large glaciers flowing out from the central ice sheet towards the ocean – the Jakobshavn Isbrae, the Kangerdlugssuaq and the Helheim.

“These three glaciers are huge and collectively, they drain as much as 40 percent of the southern half of the ice sheet. All three have recently increased their speed as the temperature rose,” Box said, adding that the Kangerdlugssuaq, at 3.1 miles (5 kilometers) wide is half-again as wide as New York's Manhattan Island .

Digging through the old data, Herrington found a map from 1932 and an aerial photo from 1933 that documented how, during a warm period, the Kangerdlugssuaq Glacier lost a piece of floating ice that was nearly the size of New York 's Manhattan Island .

“That parallels what we know about recent changes,” Box said. “In 2002 to 2003, that same glacier retreated another 3.1 miles (5 kilometers), and that it tripled its speed between 2000 and 2005.”

The fact that recent changes to Greenland's ice sheet mirror its behavior nearly 70 years ago is increasing researchers' confidence and alarm as to what the future holds. Recent warming around the frozen island actually lags behind the global average warming pattern by about 1-2 degrees C but if it fell into synch with global temperatures in a few years, the massive ice sheet might pass its “threshold of viability” – a tipping point where the loss of ice couldn't be stopped.

“Once you pass that threshold,” Box said, “the current science suggests that it would become an irreversible process. And we simply don't know how fast that might happen, how fast the ice might disappear.”

Greenland 's ice sheet contains at least 10 percent of the world's freshwater AND it has been losing more than 24 cubic miles (100 cubic kilometers) of ice annually for the last five years and 2007 was a record year for glacial melting there.

Source: Ohio State University, by Earle Holland


http://www.physorg.com/news116505069.html

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That does NOT mean we are not warming the earth. For example, Al Gore placed a lot of blame for Hurricane Katrina and the large increase in hurricanes on global warming. That is not necessarily true. But that doesn't mean global warming isn't happening.

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Global warming is happening, but who is causing it and in what form is up for debate.

Fortunately, that's becoming less and less true every day.

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~Dr. Martin Luther King, Jr.

Maybe instead of letting all that fresh water go to waste we should find some way of collecting it and putting it to use where it is most needed.

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A panda walks into a cafe. He orders a sandwich, eats it, then draws a gun and fires two shots in the air.

"Why?" asks the confused waiter, as the panda makes toward the exit. The panda produces a badly punctuated wildlife manual and tosses it over his shoulder.

"I'm a panda," he says at the door. "Look it up."

The waiter turns to the relevant entry and, sure enough, finds an explanation.

"Panda. Large black-and-white bear-like mammal, native to China. Eats, shoots and leaves."

Now that is a great idea. Plus then the amount of fresh water going into the ocean won't cause the big chaange in climate change. Plus almost everyone needs fresh water. Just keep the bottling plants out of the picture. This isn't a job for any business.

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Yea can't keep the words of your great leader.

Prophet Muhammad - “Do you love your creator? Love your fellow-beings first.”

I think itwould be easyer to clean the water there allready is all around the world, then take it from greenland

beside do you know how many people have pied in that snow up there

so what? So what caused the warming in the 1920s-1940s? Certainly not greenhouse gases as they had little effect back during that time frame.

This is simply not a classic greenhouse gas warming signature. The climate models demand that the warming be 2-3 times greater at the mid trop (the greenhouse layer) than at the surface. And since the warming is actually less at the mid trop than the lower trop, we can assume that these climate models that show such significant warming either do one of two things or both.

1) Overdo the power of these greenhouse gases or

2) Do not include as many negative feedbacks as is currently happening.