It doesn't feel hotter to me.
— George W. Bush
Also see:
Waxman Seeks Climate Inquiry
Evidence That Bush Mislead Public
AP 30jan2007
Plus offsite article:
Greenland, or why you might
care about ice physics
The Oil Drum 28jan2007
Later this week in Paris, climate scientists will issue a dire forecast for the planet that warns of slowly rising sea levels and higher temperatures.
But that may be the sugarcoated version.
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Early and changeable drafts of their upcoming authoritative report on climate change foresee smaller sea level rises than were projected in 2001 in the last report. Many top U.S. scientists reject these rosier numbers. Those calculations don't include the recent, and dramatic, melt-off of big ice sheets in two crucial locations:
They "don't take into account the gorillas — Greenland and Antarctica," said Ohio State University earth sciences professor Lonnie Thompson, a polar ice specialist. "I think there are unpleasant surprises as we move into the 21st century."
Michael MacCracken, who until 2001 coordinated the official U.S. government reviews of the international climate report on global warming, has fired off a letter of protest over the omission.
The melting ice sheets in Greenland and Antarctica are a fairly recent development that has taken scientists by surprise. They don't know how to predict its effects in their computer models. But many fear it will mean the world's coastlines are swamped much earlier than most predict.
Others believe the ice melt is temporary and won't play such a dramatic role.
That debate may be the central one as scientists and bureaucrats from around the world gather in Paris to finish the first of four major global warming reports by the Intergovernmental Panel on Climate Change. The panel was created by the United Nations in 1988.
After four days of secret word-by-word editing, the final report will be issued Friday.
The early versions of the report predict that by 2100 the sea level will rise anywhere between 5 and 23 inches (12.7 to 58 centimeters). That's far lower than the 20 to 55 inches (51 to 140 centimeters) forecast by 2100 in a study published in the peer-review journal Science this month. Other climate experts, including NASA's James Hansen, predict much bigger sea level rises.
The report is also expected to include some kind of proviso that says things could be much worse if ice sheets continue to melt.
The prediction being considered this week by the IPCC is "obviously not the full story because ice sheet decay is something we cannot model right now, but we know it's happening," said Stefan Rahmstorf, a climate panel lead author from Germany who made the larger prediction of up to 55 inches (140 centimeters) of sea level rise. "A document like that tends to underestimate the risk," he said.
"This will dominate their discussion because there's so much contentiousness about it," said Bob Corell, chairman of the Arctic Climate Impact Assessment, a multinational research effort. "If the IPCC comes out with significantly less than one meter (about 39 inches), there will be people in the science community saying we don't think that's a fair reflection of what we know."
In the past, the climate change panel didn't figure there would be large melt of ice in west Antarctica and Greenland this century and didn't factor it into the predictions. Those forecasts were based only on the sea level rise from melting glaciers (which are different from ice sheets) and the physical expansion of water as it warms.
But in 2002, Antarctica's 1,255-square-mile (3,250-square-kilometer) Larsen B ice shelf broke off and disappeared in just 35 days. And recent NASA data shows that Greenland is losing 53 cubic miles (221 cubic kilometers) of ice each year — twice the rate it was losing in 1996.
Even so, there are questions about how permanent the melting in Greenland and especially Antarctica are, said panel lead author Kevin Trenberth, chief of climate analysis at the National Center for Atmospheric Research in Colorado.
While he said the melting ice sheets "raise a warning flag," Trenberth said he wonders if "some of this might just be temporary."
University of Alabama at Huntsville professor John Christy said Greenland didn't melt much within the past thousand years when it was warmer than now. Christy, a reviewer of the panel work, is a prominent so-called skeptic. He acknowledges that global warming is real and man-made, but he believes it is not as worrisome as advertised.
Those scientists who say sea level will rise even more are battling a consensus-building structure that routinely issues scientifically cautious global warming reports, scientists say. The IPCC reports have to be unanimous, approved by 154 governments — including the United States and oil-rich countries such as Saudi Arabia — and already published peer-reviewed research done before mid-2006.
Rahmstorf, a physics and oceanography professor at Potsdam University in Germany, says, "In a way, it is one of the strengths of the IPCC to be very conservative and cautious and not overstate any climate change risk."
source: http://www.iht.com:80/bin/print.php?id=4370560 30jan2007
Serious disagreement has broken out among scientists over a United Nations climate report's contention that the world's greatest wilderness - Antarctica - will be largely unaffected by rising world temperatures. The report, to be published on Friday, will be one of the most comprehensive on climate change to date, and will paint a grim picture of future changes to the planet's weather patterns. Details of the report were first revealed by The Observer last weekend.
However, many researchers believe it does not go far enough. In particular, they say it fails to stress that climate change is already having a severe impact on the continent and will continue to do so for the rest of century. At least a quarter of the sea ice around Antarctica will disappear in that time, say the critics, though this forecast is not mentioned in the study.
One expert denounced the report - by the UN's Intergovernmental Panel on Climate Change, or IPCC - as 'misleading'. Another accused the panel of 'failing to give the right impression' about the impact that rising levels of carbon dioxide will have on Antarctica.
Antarctica possesses the Earth's greatest mass of ice and acts as an engine that drives the globe's weather systems. Disturbances to Antarctica could have wide repercussions. If all its ice were to melt, sea levels round the world would rise by 70 metres. The fate of that continent crucially affects the fate of the planet, and according to scientists at the British Antarctic Survey it is already being affected by global warming.
'The greatest temperature rise on Earth over the past five decades has been found on the Antarctic peninsula, which stretches north from the continent towards South America,' said Dr John Turner. 'Temperatures have risen 5C on the peninsula.' That figure is 10 times the average global temperature rise for the same period.
In addition, researchers reported last October that in just over a month, an entire Antarctic ice shelf, bigger than Gloucestershire, had disintegrated and disappeared, with its loss directly linked to man-made global warming.
Yet there is no mention of these events in the draft version of the panel's report obtained by this newspaper. It paints a broad picture of how carbon emissions will alter global temperatures, which will rise by between 3C to 5C by the end of the century, triggering storms of increasing severity, the acidification of seas and the spreading of deserts.
But when it comes to certain types of climate change, especially those concerned with Antarctica, the report is fairly coy. 'Current global studies project the Antarctic ice sheet will remain too cold for widespread surface melting and is expected to gain in mass due to increased snowfall,' states the draft version of the report.
But this vision is disputed. Last year, Dr Turner and colleagues, using records returned by Russian research balloons that were flown over the whole of Antarctica between 1971 and 2003, discovered that temperatures in the lowest level of the atmosphere over the continent have already risen by about 0.7C. Their paper, in Science, was published in March, too late for inclusion in the IPCC's deliberation.
Other factors - including the expected disappearance of the Antarctic ozone hole, which has had a cooling effect on the continent - will lead to a further rise of 5C-6C over parts of the continent over the rest of the century.
Critics point out that the IPCC is a conservative body whose documents are a co-operative effort, with contributions from hundreds of scientists. Only points that are considered indisputable by all of them are included. This consensus deflects potential accusations that the body might be exaggerating the threat to the planet. But the critics say it also means its documents tend to err too much on the side of caution.
'From what I hear of the report, it seems misleading to suggest nothing much is going to happen to the Antarctic over the coming decades,' said Dr Chris Rapley, director of the British Antarctic Survey.
'Some parts of the continents are already losing substantial amounts of ice and others will in future - and that will have direct consequences for the rest of the planet.'
source: http://observer.guardian.co.uk/print/0,,329698789-119093,00.html 30jan2007
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