Posted on 02/16/2006 4:54:22 PM PST by blam
Greenland ice swells ocean rise
By Paul Rincon
BBC News science reporter, St Louis
Kangerdlussuaq Glacier "drains" about 4% of the ice sheet
Greenland's glaciers are sliding towards the sea much faster than previously believed, scientists have told a conference in St Louis, US.
It was thought the entire Greenland ice sheet could melt in about 1,000 years, but the latest evidence suggests that could happen much sooner.
It implies that sea levels will rise a great deal faster as well.
Details of the study, by Nasa and University of Kansas researchers, are also reported in the journal Science.
The comprehensive analysis found that the amount of ice dumped into the Atlantic Ocean has doubled in the last five years.
If the Greenland ice sheet melted completely, it would raise global sea levels by about 7m.
Greenland's contribution to global sea level rise today is two to three times greater than it was in 1996.
Sleeping giant
"We are concerned because we know that sea levels have been able to rise much faster in the past - 10 times faster. This is a big gorilla. If sea level rise is multiplied by 10 or more, I'm not sure we can deal with that," co-author Eric Rignot, from the US space agency's (Nasa) Jet Propulsion Laboratory in California, told the BBC News website.
Previous estimates suggested it would take many hundreds of years for the Greenland ice sheet to melt completely. The new data will cut this timescale, but by how much is uncertain.
It takes a long time to build and melt an ice sheet, but glaciers can react quickly to temperature changes
Dr Eric Rignot, Nasa "It depends on how fast the glaciers can go and how sustainable the acceleration can be," said Dr Rignot.
He added: "It takes a long time to build and melt an ice sheet, but glaciers can react quickly to temperature changes."
In 1996, Greenland was losing about 100 cubic km per year in mass from its ice sheet. In 2005, this had increased to about 220 cubic km. By comparison, the city of Los Angeles uses about one cubic km of water per year.
Rising surface air-temperatures seem to be behind the increases in glacier speed in the southern half of Greenland since 1996; but the northward spread of warmer temperatures may be responsible for a rapid increase in glacier speed further north after 2000.
Satellite monitoring
Over the past 20 years, the air temperature in south-east Greenland has risen by 3C.
Warmer temperatures cause more surface melt water to reach the base of the ice sheet where it meets the rock. This is thought to serve as a lubricant, easing the glaciers' march to the sea.
Helheim Glacier loses the equivalent of about half a football field a day
The study's results come from satellites that monitor glacier movement from space.
Rignot and colleague Pannir Kanagaratnam, from the University of Kansas, built up a glacier speed map from the data for 2000 and then used measurements from 1996-2005 to determine how glacier velocity had changed in the last decade.
The researchers plan to continue their monitoring of the Greenland glaciers using satellite data.
The Greenland ice sheet covers 1.7 million sq km and is up to 3km thick.
The scientists described their results at the annual meeting of the American Association for the Advancement of Science.
Also, he said the Viking colony that was there starved to death due to climate change.
Me, I think we're still coming out of the Ice Age.
So if its happened before, prior to the Industrial Revolution????
So Greenland might actually might be green someday?
I think I heard Pat Robertson say that it is God melting the ice to punish the liberals on the east and west coasts.
So Greenland might actually be green again.
"Collapse" was very good. Required reading, IMHO.
"It was thought the entire Greenland ice sheet could melt in about 1,000 years, but the latest evidence suggests that could happen much sooner."
So in 999 years, maybe? *Snort*
Maybe they just weren't measuring them right before. I don't think they know what they are talking about.
Global sea levels up by 7 meters?
That's quite a bit more than I woulda thought.
You are probably familiar with the viking farm that was buried when the ice advanced, that has in recent years been uncovered thanks in part to the withdrawal of the ice; it is an archaelogical dig site.
It's my understanding that it's as green there today as it was when Eric decided to settle there about 1000AD.
Gulp! That means we are gonna have to start drinking more water.
The History Channel did a piece on Greenland that said the same thing; perhaps it was based on that book. The archaeological evidence suggests that the settlers increasingly tried to keep their livestock alive in barns over the ever-harsher winters but eventually had to turn almost exclusively to fish as the climate no longer supported growing enough forage. Turned out they weren't very good at fishing and didn't have enough food.
Mankind did ot beofre, and will have to do it again. The only difference thgis time is that we have the MSM & evironazis yammering about it non-stop.
An even brighter side is that this makes should make moot any plans to rebuild NOLA.
Oh, they do know! What they're doing is called research grant trolling.
Why waste it? Use it to brew whiskey!
I thought global warming was going to stop or slow down the gulf stream, making that part of the world much colder. How would Greanland continue to warm?
Wait a minute. I've spent a lot of time in Greenland, and I really like it. It's beautiful, with HUGE potential and would be a great place to live if it were only a bit warmer. Maybe I'd be wise to start buying up icy real estate for the coming boom? It's cheap now...
It was in 1000 AD and the Vikings made it into a livable and arable place. When the Little Ice Age arrived, Greenland became snowland. The sun is working its magic again, right on time.
be sure to buy a house in the mountains, just in case :)
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