Posted on 04/07/2004 8:04:27 PM PDT by NormsRevenge
LONDON (Reuters) -
Greenland's huge ice sheet could melt within the next 1,000 years and swamp low-lying areas around the globe if emissions of carbon dioxide (CO2) and global warming are not reduced, scientists said on Wednesday.
A meltdown of the massive ice sheet, which is more than three km (1.8 miles) thick would raise sea levels by an average seven meters (yards), threatening countries such as Bangladesh, island in the Pacific and parts of Florida.
"Any area that is less than seven meters above sea level would be flooded," said Jonathan Gregory, a climate scientist at the University of Reading in southern England.
Researchers have already calculated that an annual average temperature rise of more than three degrees Celsius would be sufficient to melt the ice sheet in the future.
Gregory and his colleagues have produced new calculations, which are published in the science journal Nature, showing that a temperature rise of that degree is indeed likely to happen.
"We found that the levels of CO2 which we could quite likely reach during this century are sufficient to produce that amount of warming," he said.
Using methods developed for the Intergovernmental Panel on Climate Change, Gregory and his team did modeling studies of temperature change in response to increasing concentrations of greenhouse gases over the next 350 years.
"We estimated what that meant for the temperature of Greenland to see whether it passed the critical level threshold," Gregory added.
It did.
Some of the models forecast a temperature rise that was nearly three times more than the threshold.
"How quickly it would happen would depend on how severe the warming was," Gregory said when asked when the ice sheet would disappear. "It is a great deal of ice."
Under the Kyoto Protocol (news - web sites), the European Union (news - web sites) must cut its greenhouse gas output by eight percent of 1990 levels between 2008 and 2012. To help reach these targets, the EU has designed an international emissions trading scheme, due to start in 2005.
Plants in each member state will be granted tradeable CO2 certificates which allow them to generate a set amount of the polluting gas.
But it may not be enough.
"Presuming the calculations are right, that it is going to happen, and that we are in the right ball park then you would prevent it (the meltdown) happening by not allowing CO2 to go above the levels we were considering," Gregory said.
The lowest CO2 concentration scenario used in the models was 450 parts per million. Current levels are below that, according to Gregory, but by the middle of this century are likely to exceed it.
"It would not be impossible to remain below that level, if it is the important threshold, but it will mean greater emissions reduction than is currently being considered," he added.
View of ice in northeastern Greenland. Greenhouse gas pollution is so bad that on current trends, Greenland's icesheet may start to melt by the end of this century, a scenario that eventually will drown coastlines around the world, a study warns.(AFP/HO/File)
Not waving but drowning: Greenland icesheet faces meltdown: study
PARIS (AFP) - Greenhouse gas pollution is so bad that on current trends, Greenland's icesheet may start to melt by the end of this century, a scenario that eventually will drown coastlines around the world, a study warns.
Destruction of the icesheet -- second in size to Antarctica's -- would drive up sea levels by seven metres (22.75 feet) over a thousand years or more, and the process may well be irreversible, it says.
Indeed, tentative evidence suggests the icesheet has already to started to melt, lead author Jonathan Gregory told AFP.
"It's quite possible that Greenland is already making a slight contribution to global sea levels," said Gregory, a meteorologist at the University of Reading, southern England.
Published on Thursday in the British weekly science journal Nature, the research uses a sophisticated computer model to forecast what happens to the icesheet at different levels of carbon dioxide (CO2) emissions -- the gas spewed out by the burning of fossil fuels that drives global warming.
Before industrialisation, the atmosphere contained 280 parts per million (ppm) of CO2. At present it stands at 370 ppm.
The computer model ran through various scenarios, in which CO2 is stabilised at 450, 550, 650, 750 and 1,000ppm.
And it factored in the latest data that points to how parts of the northern hemisphere are particularly vulnerable to global warming.
The risk factor here is a phenomenon called albedo: the ability of a landscape to reflect sunlight.
Ice and snow reflect sunlight, and thus heat. The more exposed a landscape is, the more heat it absorbs; this in turn melts more of the ice, and so the warming process continues, becoming a vicious circle.
In most of the combinations that were crunched through the computer model, Greenland warmed by about 3.0 degrees Celsius (5.4 Fahrenheit) by 2100 compared with 1990 levels, a temperature at which the icesheet starts to contract, for melting will exceed snowfall.
In many cases, the warming is predicted to exceed eight decrees Celsius (11.2 Fahrenheit) by the year 2350, a temperature virtually considered a doomsday by the UN's top scientific body on global warming, the Intergovernmental Panel on Climate Change (IPCC).
The study points out that the lowest CO2 concentration used in the model, of 450ppm, is almost certain to be exceeded by 2050 alone -- and that carbon dioxide is only one of six important greenhouse gases.
"We conclude that the Greenland icesheet is likely to be eliminated by anthropogenic (man-made) climate change unless much more substantial emission reductions are made than those envisaged by the IPCC," the authors say.
"This would mean a global average sea-level rise of seven metres during the next 1,000 years or more."
Even if CO2 levels and global temperatures return to pre-industrial levels, the icesheet may never be regenerated, because Greenland's landmass would have warmed because of the loss of albedo.
The only international agreement on cutting greenhouse gases is the UN's Kyoto Protocol (news - web sites), which requires industrial countries to make a small cut in global emissions by a timeframe of 2008-12.
But the pact is in limbo. It still needs ratification by Russia to take effect and in any case has been abandoned by the United States, the world's biggest CO2 polluter.
And Santa Claus could fly out of my butt
AHHHHHHHHHH!!!! WE'RE ALL GONNA DIEEEEE!!!!!!
THINK OF THE CHILDREN.
AHHHHHH!!!!!
Meaning junk science!
Yeah, and I COULD hit the Powerball jackpot this weekend.
More greenhouse gas comes from Paris than it does from anywhere else.
By 2050, I am 100% certain that we will have forgotten about all these phoney predictions and models.
I like your chances at hitting the powerball better. .
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