Even Before Its Release, World Climate Report Criticized As Too Optimistic - NYT

[hatrack]

In its 2001 assessment, its third, the Intergovernmental Panel on Climate Change estimated that in the next hundred years sea level would rise globally by at least a few inches and perhaps as much as three feet, a catastrophe for low-lying coastal areas and island nations. In Paris today the panel will issue its fourth assessment, and people familiar with its deliberations say it will moderate its gloom on sea level rise, lowering its worst-case estimate.

In theory that is good news, because rising seas bring erosion and flooding to coastal areas. But a lower estimate has not been uniformly cheered. In letters to and conversations with panel members, and in scientific journals, several climate experts said the estimate was almost certainly wrong because the panel was leaving out a growing body of data on melting glaciers and inland ice sheets, which are major contributors to sea level rise. Those experts say that unless the finding is modified, the panel — widely cited as an authoritative voice on climate change — risks condemning itself to irrelevance.

Climate experts have “a great deal of confidence” in observations that sea level rise is accelerating, said Laury Miller, an oceanographer at the National Oceanographic and Atmospheric Administration who was a reviewer for part of the coming report. Good satellite measurements date only from the last decade or so, he said, so it is hard to draw firm long-term conclusions from them. Also, he said, computer models of how glaciers and ice sheets melt cannot account for much of the observed melting, even though “presumably it is going into the ocean.” But so far at least, he said, “the observed sea level rise has been tracking the upper range” of the 2001 estimate. “It’s pretty unequivocal,” he said.

Michael C. MacCracken, who led the Office of Climate Change in the Clinton administration and who was also a reviewer for some of the new assessment, said he could understand why scientists on the panel might be uneasy about relying too much on models. But in that event, he said, they should make it known that their estimates did not include factors like ice sheet movement and collapse, which appear to be accelerating.

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http://www.nytimes.com/2007/02/02/science/02oceans.html?_r=1&oref=slogin

[YankeyMCC]

1. k n r

[phantom power]

2. I was interested to see not much discussion of drought.

[amandabeech]

3. I agree.

Lack of rain or irrigation water for tillable soil will mean less food for a growing world population.

Lack of food will hurt everyone, no matter where they live.

[phantom power]

4. Their precip models appeared to be uncertain over large areas.

major disagreements over the sign of the change: no certainty about increase or decrease. I was surprised.

[amandabeech]

5. It seems that the modeling does not focus on precipitation.

From that, I would deduce that the models don't deal well with water vapor in general, which is surprising considering the importantance of cloud cover to temperature.