How the IPCC glaciers paragraph was reviewed
January 25, 2010, 6:01 pm
Filed under: Media

On the subject of the glacier claims in the Asia chapter of Working Group II’s contribution to the fourth assessment, here’s what was said in the review process (relevant pdfs here) about the passage with the 2035 disappearance figure and the 500,000 km^2 to 100,000 km^2 area reductions. The nearest thing I can see to a direct criticism comes from the Japanese government. It concentrates on confidence rather than on source but obviously the two are linked.

This seems to be a very important statement, possibly should be in the SPM [summary for policy makers], but is buried in the middle of this chapter. What is the confidence level/certainty? (i.e.“likelihood of the glaciers disappearing is very high” is at which level of likelihood? (ref. to Box TS-1, “Description of Likelihood” [this is where qualitative descriptions of likelihood are equated to quantitative statements of probability, with “very likely” meaning >90% probability). Also in this paragraph, the use of “will” is ambiguous and should be replaced with appropriate likelihood/confidence level terminology.

The response to this was “Appropriate revisions and editing made”.

Wong Poh Poh, of the National University of Singapore, asked for some more detail

Table 10.10. Provide examples of rates of retreat of glaciers outside Asia (e.g. Alpine, Arctic) to show that Himalayan glaciers are indeed receeding faster.

Response: “Revised the section”.

Two points on the sentence “Its total area will shrink from the present 500,000 to 100,000 km2 by the year 2035.” from David Saltz of the Desert Research Institute, Ben Gurion University

What does ‘its’ refer to?

100,000?  You just said it will disappear.

Answers “glaciers” and “Missed to clarify this one”

There are also a number of review comments from Hayley Fowler of Newcastle University, drawing on her own research on water availability and teh broader literature, such as this one.

I am not sure that this is true for the very large Karakoram glaciers in the western Himalaya. Hewitt (2005) suggests from measurements that these are expanding – and this would certainly be explained by climatic change in preciptiation and temperature trends seen in the Karakoram region (Fowler and Archer, J Climate in press; Archer and Fowler, 2004) You need to quote Barnett et al.’s 2005 Nature paper here – this seems very similar to what they said. “

Response “Was unable to get hold of the suggested references: will consider in the final version”: In the finished product, as far as I can see, Archer and Fowler are quoted (as they were in the second order draft), Hewitt, Fowler and Archer and Barnett et al are not.

Clair Hanson, who was at the time part of the technical support unit for WGII, raises the lack of references in various sections of the Asia chapter (Dr Wong raises a similar point, as does Mick Kelly of UEA). The response was “more references added”.

This last bit may be crucial. Up until the second order draft, there was no reference at all for the problematic paragraph on glaciers; the reference to the WWF report was added later, and thus rather at the last minute. This fits pretty well with the idea that the original source was the Down to Earth article, which contains things that are there in the IPCC report but not in the WWF article. Apart from the addition of that reference, the only other changes to the passage during the editing process, as far as I can see, are cosmetic, and do not really correspond to the replies made to the people who commented during the review. “About 15,000 Himalayan glaciers form a unique reservoir which supports perennial rivers such as the Indus, Ganga and Brahmaputra which, in turn, are the lifeline of millions of people,” in the first draft becomes rather more exactly “About 15,000 Himalayan glaciers form a unique reservoir which supports perennial rivers such as the Indus, Ganga and Brahmaputra which, in turn, are the lifeline of millions of people in South Asian Countries (Pakistan, Nepal, Bhutan, India and Bangladesh)”. “The earth keeps getting warmer” becomes “The earth keeps warming”. And a sentence that adds drama but not information, ” The glaciers will be decaying at rapid, catastrophic rates,” is dropped.

So no one specifically said the claims about the glaciers are wrong. But they did raise some other points to which, apparently, little heed was paid.


2 Comments so far
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I started a new site to collect info on the Himalayan glaciers, called Not in 2035 (http://notin2035.com).

Since the IPCC section on these glaciers was wrong, I’m trying to get the best possible information I can, and also help point out where the mistaken claims have been repeated in other scientific articles, to help the community self-correct. I hope people will comment, pointing me to papers to mention.

Comment by Mason Inman

[…] some of the mistakes that have now come to light. (See Oliver Morton’s post on Heliophage, “How the IPCC Glacier Paragraph Was Reviewed”, for details.) Basically, problems were brought up, but the authors of the report didn’t […]

Pingback by Not in 2035 » Blog Archive » Should the IPCC start a wiki?

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