While traveling I received several emails about the latest cause celebre of climate change “skeptics,” a badly sourced prediction that Himalayan glaciers could disappear by the year 2035, attributed to the World Wildlife Fund in an IPCC report. The London TimesOnline story about this was headlined, “World misled over Himalayan glacier meltdown,” which sounds pretty bad. Those evil scientismists, up to their tricksy ways again.

RealClimate has a good post on the issue, acknowledging the need to correct the error and work harder to ensure that poorly sourced claims aren’t included in IPCC documents — but also making the much larger point that although the 2035 prediction may not have been sourced properly, the glaciers of the Himalayas are still receding rapidly: RealClimate: The IPCC is not infallible (shock!).

Like all human endeavours, the IPCC is not perfect. Despite the enormous efforts devoted to producing its reports with the multiple levels of peer review, some errors will sneak through. Most of these will be minor and inconsequential, but sometimes they might be more substantive. As many people are aware (and as John Nieslen-Gammon outlined in a post last month and Rick Piltz goes over today), there is a statement in the second volume of the IPCC (WG2), concerning the rate at which Himalayan glaciers are receding that is not correct and not properly referenced.

The statement, in a chapter on climate impacts in Asia, was that the likelihood of the Himalayan glaciers “disappearing by the year 2035″ was “very high” if the Earth keeps warming at the current rate (WG 2, Ch. 10, p493), and was referenced to a World Wildlife Fund 2005 report. Examining the drafts and comments (available here), indicates that the statement was barely commented in the reviews, and that the WWF (2005) reference seems to have been a last minute addition (it does not appear in the First- or Second- Order Drafts). This claim did not make it into the summary for policy makers, nor the overall synthesis report, and so cannot be described as a ‘central claim’ of the IPCC. However, the statement has had some press attention since the report particularly in the Indian press, at least according to Google News, even though it was not familiar to us before last month.

It is therefore obvious that this error should be corrected (via some kind of corrigendum to the WG2 report perhaps), but it is important to realise that this doesn’t mean that Himalayan glaciers are doing just fine. They aren’t, and there may be serious consequences for water resources as the retreat continues. See also this review paper (Ren et al, 2006) on a subset of these glaciers.

Here’s a little more perspective on this flawed prediction: it’s quoted only in one paragraph in the second volume of the IPCC’s fourth Assessment Report — and not in any of the technical summaries, which are more widely read, but only on page 493 of Chapter 10 of this very lengthy document on the impacts of climate change (PDF).

So yes, it’s a breakdown in the scientific vetting process for these kinds of claims, but on the other hand it’s been vastly exaggerated and blown up into a huge issue, far beyond what is warranted. If you’re really interested in the subject, I recommend at least glancing through the other 3000 pages of the AR4 documents to see how much information and research is not in question.

For some graphic evidence of the effects of global warming in the Himalayas, RealClimate posted this photo showing a then-now image of the East Rongbuk glacier: