Fred Derf Veteran Posted March 24, 2006 Veteran Share Posted March 24, 2006 Scientists say the vast icy landscape of Greenland is thinning, and many blame global warming. Ice caps melting faster than forecast `It's not a gradual change. It's like flipping a switch,' researcher says New reports warn of sea levels rising up to 5 metres, extensive flooding Mar. 24, 2006. 10:17 AM PETER CALAMAI SCIENCE REPORTER Global warming of only a couple of degrees Celsius projected by the end of this century is enough to trigger widespread melting of the massive Greenland ice cap and the partial collapse of Antarctica's ice sheets, prominent climate researchers warn in two studies published yesterday. The findings are a stunning about-face from previous expert forecasts that such massive melting would take millennia to kick in, even with rising global atmospheric levels of carbon dioxide and other greenhouse gases. This new research, based on a comprehensive look at global warming in the distant past, says melting the two icy domains could eventually raise sea level worldwide by as much as five metres, enough to flood low-lying regions like the Netherlands and most Pacific atolls, as well push half a billion people inland. The full five-metre rise could take several centuries but the world's oceans could easily be a metre higher by 2100, the researchers said. "The melting is going to happen faster than we thought. It's already begun to happen," said University of Calgary ice researcher Shawn Marshall, the sole Canadian among the authors of the two studies published by the journal Science. "We could be past the point of no return for Greenland this century," he said in an interview. A 1998 federal government report rated most of P.E.I., the eastern coast of Nova Scotia and the Beaufort Sea shore in the Western Arctic as "highly sensitive" to a global sea level rise of under seven-tenths of a metre. Marshall and the other researchers acknowledged they were taken by surprise by the breakneck escalation in the melting of glaciers and ice sheets in recent years. Since 1980 the portion of the Greenland ice cap experiencing annual melting has increased by 40 per cent. "It's not a gradual change. It's like flipping a switch. Areas that haven't experienced melt in centuries suddenly do," said Marshall. A widely quoted report in 2001 from the Intergovernmental Panel on Climate Change concluded that major melting was no threat in Greenland and Antarctica in this century. But Jonathan Overpeck, a climate scientist at the University of Arizona, said the new research shows these massive ice sheets are much more sensitive to global warming than originally suspected. "Once we're above two times the pre-industrial levels of carbon dioxide we're in the danger zone," said Overpeck, who is lead author on one of the studies. "Somewhere after that we'll pass a threshold where melting of the ice sheets and sea level rise is irreversible," he said. Most experts agree that carbon dioxide concentrations double the pre-industrial level will be reached sometime after 2050 unless global emissions are at least cut in half. The current atmospheric concentration of carbon dioxide is about 380 parts per million compared to 280 parts per million before widespread burning of fossil fuels began around 1870. Under the Kyoto Protocol, industrialized countries have pledged to reduce their overall emissions of greenhouse gases to 5 per cent below 1990 levels starting in 2008. But soaring emissions from China and other developing countries ? and the Kyoto boycott by Australia and the United States ? mean that global carbon dioxide levels are expected to continue rising steadily. The new warning is based on using climate extremes from the last major global warming to check the reliability of future climate conditions projected by complex computer models. A prolonged hot spell began 129,000 years ago because natural orbital variations caused the Earth's northern axis to tilt more toward the sun producing much higher temperatures in the northern hemisphere, especially the Arctic. A decade-long international research project gathered an evidence of climate change from that period, including the disappearance of glaciers in Canada's Arctic archipelago, halving of Arctic sea ice coverage, major shrinking of the Greenland ice cap and a northward march of the boreal forest. Examination of Australia's Great Barrier Reef also indicated that sea levels were four to six metres higher than today. A group of U.S. researchers then produced many of the same results by simulating increased sun on the northern hemisphere in an advanced climate model which Calgary's Marshall beefed up to handle glacier movements and ice melting. "The model got it about right for the past which gives us more confidence in its forecasts," said Marshall. A second research team, led by Overpeck, then used the souped-up model to project what would happen to the Earth's ice cover if global temperatures were raised by higher levels of carbon dioxide rather than a shift in the planet's tilt. They found that tripling pre-industrial carbon dioxide levels by 2100 caused widespread melting in Greenland and the Arctic but didn't raise sea levels the five metres recorded in the Australia reefs. The Western Antarctic Ice Sheet must also melt, the scientists concluded. Even a two degree Celsius rise in global average temperature would cause thermometers to soar as much as eight or 10 degrees in the Arctic and Antarctic, a feedback process known as polar amplification. "All the things we were worrying about happening did happen and it didn't take that much warming," said Overpeck. http://www.thestar.com/NASApp/cs/ContentSe...72154&t=TS_Home Link to comment Share on other sites More sharing options...
dacris2000 Posted March 25, 2006 Share Posted March 25, 2006 "The full five-metre rise could take several centuries but the world's oceans could easily be a metre higher by 2100" Not exactly flipping a switch now is it? "Even a two degree Celsius rise in global average temperature would cause thermometers to soar as much as eight or 10 degrees in the Arctic and Antarctic, a feedback process known as polar amplification." Hmm... so the equator and tropical regions don't change as much? Doesn't this mean that the "livable" region of the earth expands higher into the polar regions, allowing for more human/animal/plant habitation, and expanding the earth's overall ecosystem? Personally, I think global warming is a good thing. Whether man-made or natural. We've been living in an ice age for too long. It is NOT normal for the poles to be below zero all year for a planet that's as close to the sun as Earth. We can clearly see that the Earth's current ecosystem is severely restricted in range. Above 70*N and below 70*S, there's virtually no life. Those massive ice sheets aren't doing anyone any good. So what if sea levels rise? It'll be a gradual process. People will move. I don't think it's as catastrophic as they make it out to be. Link to comment Share on other sites More sharing options...
Boffa Jones Veteran Posted March 25, 2006 Veteran Share Posted March 25, 2006 "The full five-metre rise could take several centuries but the world's oceans could easily be a metre higher by 2100" Not exactly flipping a switch now is it? "Even a two degree Celsius rise in global average temperature would cause thermometers to soar as much as eight or 10 degrees in the Arctic and Antarctic, a feedback process known as polar amplification." Hmm... so the equator and tropical regions don't change as much? Doesn't this mean that the "livable" region of the earth expands higher into the polar regions, allowing for more human/animal/plant habitation, and expanding the earth's overall ecosystem? Personally, I think global warming is a good thing. Whether man-made or natural. We've been living in an ice age for too long. It is NOT normal for the poles to be below zero all year for a planet that's as close to the sun as Earth. We can clearly see that the Earth's current ecosystem is severely restricted in range. Above 70*N and below 70*S, there's virtually no life. Those massive ice sheets aren't doing anyone any good. So what if sea levels rise? It'll be a gradual process. People will move. I don't think it's as catastrophic as they make it out to be. And when your kids are adults they will be cursing the way you think as well as poor planning if they live on the coast because their houses will be worth next to nothing as the water slowly gets higher and higher untill their basements are flooded and their streets are rivers. Link to comment Share on other sites More sharing options...
davemania Posted March 25, 2006 Share Posted March 25, 2006 (edited) Personally, I think global warming is a good thing. Whether man-made or natural. We've been living in an ice age for too long. It is NOT normal for the poles to be below zero all year for a planet that's as close to the sun as Earth. We can clearly see that the Earth's current ecosystem is severely restricted in range. Above 70*N and below 70*S, there's virtually no life. Those massive ice sheets aren't doing anyone any good. So what if sea levels rise? It'll be a gradual process. People will move. I don't think it's as catastrophic as they make it out to be. It's not normal ? As for the poles, its cold because of the earth's tilt. Maybe the 6 month of darkness gave it away ? The raise of sea level will also impact our food supply, economy, resource allocation, weather patterns. Its not as simple as people moving around and everything will be back to normal. Edited March 25, 2006 by davemania Link to comment Share on other sites More sharing options...
~WinGz~ Posted March 25, 2006 Share Posted March 25, 2006 Even though theirs the good things that could result from this. Such as, ecosystem is better, and our ice age ends. There could be alot of catastrophic events. The events in that disaster movie the day after tomorrow, could just occur from it. Also all the beach front properties would be gone and all. but most of that land was probably originally under the ocean as it was. Global Warming has its ups and downs. Maybe we will see the ups to it. -Nice find Fred- Link to comment Share on other sites More sharing options...
Fred Derf Veteran Posted March 25, 2006 Author Veteran Share Posted March 25, 2006 Don't forget that wet areas get wetter (Gulf Coast) and dry areas get dryer (mid-West). Expect to see desert-like conditions in the interior of the North American continent. If you think that is a good thing then I don't know what to say... Link to comment Share on other sites More sharing options...
Beastage Posted March 25, 2006 Share Posted March 25, 2006 The truth is that the desert is the fastest growing climate region in the world. So basically, its the coast line getting smaller and the desert getting bigger, sounds like a lose-lose situation to me Link to comment Share on other sites More sharing options...
sharpy2k4 Posted March 25, 2006 Share Posted March 25, 2006 i personally think, we should get the water being "melted" bring it over to the Uk, we need water as we're in a "severe drought" supposedly, or we could just get it on africa ..... Link to comment Share on other sites More sharing options...
The_Decryptor Veteran Posted March 26, 2006 Veteran Share Posted March 26, 2006 We don't need no stinking dry land. /me releases tones of C02 into the atmosphere. Link to comment Share on other sites More sharing options...
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