Politics was not the impetus for the mistake, he maintains.

By Janet Raloff

Web edition: January 27, 2010

As noted in a blog, last weekend, London’s Sunday Mail quoted the lead author of a chapter in a purportedly authoritative 2007 climate-change assessment as saying that he deliberately used unsubstantiated sources for conclusions about the rate of glacier melting in the Himalayas. After two days, I finally reached the scientist in question — Murari Lal — in Ghaziabad, India, where he chairs the Climate, Energy and Sustainable Development Analysis Centre. Lal doesn’t dispute that mistakes were made in the inclusion of some numbers in his chapter of the report — ones that likely exaggerated projections of glacier melting. But he strenuously challenges the newspaper’s charge that those mistakes were politically motivated.

In that newspaper story, the Mail’s David Rose quoted Lal as saying about the Himalayan glacier melt projection: “We thought that if we can highlight it, it will impact policy makers and politicians and encourage them to take some concrete action.”

But in a series of email exchanges with me, Lal counters that he never said that. He's not saying he was quoted out of context. He flatly denies ever uttering those words. He similarly denies several of the other quotes attributed to him in that article. And he points out that the newspaper misidentified his field of study as glaciology. He is, in fact, a climatologist.

The Intergovernmental Panel on Climate Change, which issued the report in which the disputed Himalayan glacier data appeared, has called the use of a non-peer-reviewed source — in this case a report by the World Wildlife Fund — a mistake.

I asked Lal how he happened to rely on that WWF material.

None of the IPCC chapter's authors were glaciologists, he said, so “we entirely trusted the findings reported in the WWF 2005 Report and the underlying references as scientifically sound and relevant in the context of climate change impacts in the region.” Those underlying references, he says, cited projections by a renowned Indian glaciologist. So Lal says his team deferred to what appeared to be that scientist’s assessments (projections that have apparently since been retracted).

“As authors,” he says, “we had to report only the best available science inclusive of a select few (non-peer-reviewed sources) which is ‘policy-relevant and yet policy-neutral’ — and that's what we collectively did while writing the Asia Chapter.”

Keep in mind, Lal argues, the 2035 figure contained in his chapter — as a date at which Himalayan glaciers might disappear — was not a prediction, but a projection. IPCC authors are prohibited from making their own predictions, he said. And, he argues, his team didn't. Indeed, he maintains, “We did not violate the existing IPCC procedures in any manner.”

So, what is his current assessment of the Himalayan melt situation? “I and my colleagues in [the] Asia Chapter firmly believe that some of the Himalayan glaciers and also the glaciers over [the] Tibetan Plateau are melting (irrespective of the statistically significant inter-annual variability).” As such, Lal says, these glacial retreats could have important ramifications for the water resources in many south Asian countries. However, gauging how serious the glacial-melt situation is in this region remains difficult since the Himalayas “are the least assessable region of the globe and more ground truths on a longer time scale are required.”

The scientist does acknowledge that mistakes crept into the IPCC climate report. As he describes it, some questionable numbers (not his phrasing, that’s mine) on the extent of glacial melting  “must have skipped our attention and [were] somehow missed during the reviews as well.” These were simply mistakes, he says, to which “no deliberate motives should be attached.”

What this whole controversy does indicate, he says, is that IPCC should not rush to meet deadlines such that deadlines override quality assurance. Rather, he would like to see IPCC institute changes to peer review so that when there’s a conflict, quality assurance will trump publishing deadlines. And because some mistakes are bound to occur whenever hundreds of people are involved in reviewing and assessing so much data, he said, IPCC should institute a formal mechanism to correct errors that may only come to light — as here — after publication.

The recent Himalayan glaciers are not the only thing in retreat. Lal suggests he’s prepared to retreat from his role on the IPCC stage.

“I have put my heart and soul for almost 20 years into the IPCC Science Assessment Process,” he says, “with the sole objective to serve the humanity on planet Earth as a responsible, educated citizen, without aspiring for any reward or recognition. However, under the current state of this scenario (the situation has become quite bizarre at the moment and IPCC's credibility is now at stake), I am not interested in being associated with the IPCC process any more or getting involved in political controversy/advocacy.”

I don’t know what Lal told Rose, last weekend, and whether Rose reported faithfully or not. (Indeed, just as mistakes can creep into documents on science, they can creep into news stories prepared on deadline.) The real issue, however, is the science and how it is reported and interpreted. And how errors are dealt with. Clearly, Lal is correct when he argues that procedures must exist to correct mistakes when they come to light, be it days, or even years, after a document is published. After all, it's folly to expect mistakes will not happen.

And perhaps if gray literature — non-peer-reviewed material — must occasionally be used (although IPCC ostensibly prohibits it), any use of such exceptions should be highlighted. This procedure would not only serve to warn readers of the material’s iffy nature, but also point to where more research should be focused — precisely so that there eventually will be no need to rely on gray literature.