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.
Gulp! That means we are gonna have to start drinking more water.
But... Whatever you do please don't pee in the ocean.
I agree with your observations and just have a couple of comments. The West is already in population decline and Western Europe may well have collapsing populations (non-Muslim) in a couple of decades. World population will probably peak mid-century, seem relatively stable for a few decades, and then begin the same pattern of decline. Ehrlich's prediction will never come true.
The world can easily feed the peak 2050 population - unless true believers of the Church of Environmental Radicalism succeed in shutting down the Green Revolution due to their Luddite opposition to "biologically engineered foods."
Most petroleum producers keep 30+ years of reserves on "the books." They constantly look for more to replenish them and so far have found them. But true believers misuse the reserve numbers to claim we will "run out" at the end of the booked reserves, assuming, as you point out, that no more oil can be found. Frankly, if oil does begin a period of decline, the economics will change to favor substitutes, such as nuclear for electricity or perhaps hydrogen for autos. But right now the economics are swinging in favor of production from oil sands and oil shale, which are enormous reserves.
I'd say if Ehrlich had any sense of shame and wasn't such a religious fanatic, he'd apologize to you and everyone he has deceived and criticized, publicly and often!
ping
That way your body gets rid of excess iron.
This is opposite the problem faced by people who acquire so much iron they have a toxic reaction and have to be bled and/or have transfusions.
Heme is photreactive. If you have a high concentration going out through your kidneys, it may even turn red or purple in sunlight!
Living North of the 30th parallel is an adventure in genetics, not just getting used to very long nights in the wintertime.
Old Farmers Almanac runs that story every few years.
Where do I buy my future beachfront property? Kansas?
Wisconsin is full of rocks ~
Does this take into consideration that the ice sheet in Antarctica is growing?
I'm about 40 feet above sea level here, and can see the Napa River so does that mean I get to have ocean front property?
Most of California'a coasts are well above sea level, but parts of the Central Valley are not. So does that mean you plan to do with fewer almonds, walnuts, rice, peaches, oranges, lemons, alfalfa, barley, tomatoes, lettuce, spinach, melons, yams, sugar from sugar beets, corn, grapes for fresh eating , raisins and wine; asparagus, artichokes, beans, peas, peppers,etc.......? Just to mention a few of the plant crops grown.
Just part of why California's in the top 10 of the world economies.
Therefore the global warming supposedly adversely affects Greenland (warming) , BUT all weather/ocean dynamics beyond Greenland is adversely affected (cooling). Then you have the 'reason' why Europe/Russia are so cold these last few years.
Not a fan of junk science but just setting forth what is being presented these last few years.
Therefore the global warming supposedly adversely affects Greenland (warming) , BUT all weather/ocean dynamics beyond Greenland is adversely affected (cooling). Then you have the 'reason' why Europe/Russia are so cold these last few years.
Not a fan of junk science but just setting forth what is being presented these last few years.
Close enough.
I've read that this whole thing could occur (once started) in as little as two years time.
Okay, thanks.
One flaw in your (and others) approach is that it assumes that the surface area of the oceans remain constant. This would not be the case as the surface area would theoretically increase, thus reducing this 7 m rise in the water level to something much less.
At the end of my backyard is a small tidal stream and past that a mangrove. I see it all the time. The water level is the same -- has not changed in the last 20 years. Not higher, not lower - well, it goes up and down with the tides, but that's it.
No, not much less. If it convered the entire surface area of the earth, it could only reduce the 7 m predicted rise by 40%. Of course, the area of land flooded by a 7 m rise will be less than 10% of the total land area, or less than 3% of the surface area of the earth, and so the effect on the 7m sea-level rise will be negligible.
And it is melting at the rate of 220 cubic km per year. At that rate it will take 11,500 years to melt. They must be assuming some kind of ridiculous acceleration fear-factor rate to say this will have in a couple hundred years.
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