Newspapers such as the London Times are reporting that the IPCC is about to retract something from the AR4 WG2 report:
A central claim was the world’s glaciers were melting so fast that those in the Himalayas could vanish by 2035.
The claim was indeed wrong. John Nielsen-Gammon has written a detailed analysis of the error with an update here. I’ve discovered a bit more about it, which I will get to presently, but first I want to look at the Times statement that it was a “central claim” and the New York Times statement that it was a “much-publicized estimate”.
Actually, the estimate does not appear in the WG2 summary and was mostly ignored by the media when the report came out. The Times story on the WG2 did not mention the estimate at all — their story about the mistake is actually longer than their story about the release of the report.
I did a Factiva search for news stories that mentioned Himalayan glaciers melting by 2035 and found 198 (not counting duplicates). But the majority of these were recent stories about the IPCC mistake. Only a handful of others attributed the estimate to the IPCC report (even though there were hundreds of stories about the report). More common were stories based on the 1999 New Scientist story, like this one in The Times which makes the same mistake as the IPCC, reporting:
Himalayan glaciers could vanish within 40 years because of global warming, according to a research study. … One of the researchers involved, Syed Hasnain, of the Jawaharlal Nehru University in Delhi, said studies indicate that the glaciers in the region could be gone by 2035.
This is not to excuse the IPCC’s error — we expect higher standards from them than from the The Times.
John Nielsen-Gammon notes something else that The Times got wrong:
I am quite dismayed by the last paragraph of the Times Online article:
“The revelation is the latest crack to appear in the scientific concensus over climate change. …”
Latest crack in the consensus??? The whole point is that the IPCC report didn’t reflect the consensus. The consensus, as far as we know, was right all along. And the Working Group 1 report of the IPCC reflected that consensus, with solid references to the peer-reviewed literature. The lesson here is that the IPCC does not deserve blanket trust for what they write; their reports are only as good as the references on which they’re based. And if the author had stuck to the IPCC’s own protocols for relying on the peer-reviewed literature, this mistake would never have been made in the firsts place.
Of course, global warming deniers seized on the error to argue that the IPCC can’t be trusted
The Opposition energy spokesman, Nick Minchin, a climate change sceptic, said the report highlighted the ”disturbing” lack of scientific rigour around the IPCC 2007 report.
“These revelations provide even further evidence of the Rudd Government’s recklessness in relying on dubious reports such as this as part of its scare campaign to push the urgent need to introduce a CPRS [emissions trading scheme] ahead of the world,” Senator Minchin said.
But if even relatively obscure errors in the IPCC reports get corrected, that should increase our confidence in the accuracy of the more prominent statements.
And deniers are also pretending that this error proves that Himalayan glaciers aren’t melting. For instance, The Australian‘s Cut and Paste:
See the iceman leaveth. George Monbiot, in The Guardian on May 10, 2005, on why David Bellamy was wrong to suggest glaciers were not shrinking:
“It is hard to convey just how selective you have to be to dismiss the evidence for climate change. You must ignore an entire canon of science, the statements of the world’s most eminent scientific institutions, and thousands of papers published in the foremost journals.”
Or more likely stayeth. The Australian yesterday:
Flawed communication between teams of scientists caused the UN climate change agency to claim most Himalayan glaciers would melt almost 300 years earlier than forecast, glaciologists claim.
Glaciers in the Himalaya are receding faster than in other any part of the world (see Table 10.10 below) and, if the present rate continues, the likelihood of them disappearing by the year 2035 and perhaps sooner is very high if the Earth keeps getting warmer at the current rate. The glaciers will be decaying at rapid, catastrophic rates. Its total area will shrink from the present 500,000 to 100,000 km
2 by the year 2035.
There was no cite at all for the claim and more than one reviewer noted that a citation was needed. If the chapter authors had followed this comment, all would have been well:
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 precipitation 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. (Hayley Fowler, Newcastle University)
But the response was this:
Was unable to get hold of the suggested references will consider in the final version
Instead the authors added to a cite to this WWF report, which says
“In 1999, a report by the Working Group on Himalayan Glaciology (WGHG) of the International Commission for Snow and Ice (ICSI) stated: “glaciers in the Himalayas are receding faster than in any other part of the world and, if the present rate continues, the livelihood of them disappearing by the year 2035 is very high”.
And here we see the perils of lazy citing. The IPCC report should have cited the WGHG/ICSI report, but the authors weren’t able to get hold of it. If they had, they would have found that it doesn’t say anything about the glaciers disappearing by 2035. The WWF report authors hadn’t seen the WGHG report either, but relied on this New Scientist story, by a reporter that hadn’t seen the report either, but had talked to the author of the WGHG report.