Posted on 12/10/2007 4:05:10 PM PST by sourcery
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
“We have an agenda and you can show us no facts that will deter us from following that agenda.”
At one time we were in an ice age. Then it warmed up. We weren’t even around to cause it.
BIG GIANT Poof, all fixed. Icecap note: In the Northern Hemisphere, the ice and snow cover have recovered to within 1% (one snowstorm) of normal with the official start of winter still more than 12 days away
They forgot the Mideival warm period in their calcs as well.
Seems the Icelandic shelf once had warm water plankton living on it.
http://www.co2science.org/scripts/CO2ScienceB2C/data/mwp/studies/l2_icelandicshelf.jsp
It’s like the Dems and their “If it disproves our position, it proves our position” statements.
"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."
That is, of course, unless it got cold again...
They’re forgetting the Medieval warm period.
2007 marks the beginning of the end of the Global Warming Hoax. That fact is a far better "inconvenient truth".
Back then it melted fast and then slowed but continued to melt; now it is warmer than ever and it should start melting faster again soon and when it does, it’s going to go all the way.
Is that what they’re saying?
The Global Warming Religion has removed the term “cycles” from their doctrine. Obviously.
Are these guys scientists, or are they vying for screenwriter positions to create the next blockbuster hollyweird movie?
And should the Antarctic melt, being the giant ice cube that it is floating in the ocean, it ain't going to make one bit of difference!
Thanksgiving turned into a globalwarming war between myself and my doctor bro-in-law. I stated that all the floating ice masses on this planet melting would have no affect whatsoever on the ocean levels and he of course disputed my claim.
I then conducted the kindergarten level physics test of filling a glass of water to the brim with ice and measured the overflow of water as the ice melted. It didn't..............
The glaciers must have returned if it’s happening again today. Does this reinforce the idea of natural warming cycles of the earth?
[It happened before without ill effect and without catastrophic events, yet it bolsters the theory?]
That’s why NYC was under 30’ of ocean in the 20’s. What BS. This is exactly what the park people in Alaska told us of their glaciers.
......... Including..... AL GORE!
Al Gore is criticised for lining his own pockets after £3,300-per-minute green speech
Must be why they had the shipyards there.
*groan*
;-)
> ... and melting of Greenland ‘s ...
And this place is named Greenland
instead of Whiteland for what historical reason?
Hey Big AL,
we could use some Global Hot Air (TM)
here in KS just now.
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