Himalayan glaciers: Weaknesses in IPCC review to the fore

by R. Ramachandran

Mechanism had failed to scrutinise the voluminous main assessment report

The review by the Inter-Academy Council (IAC) of the working of the Inter-governmental Panel on Climate Change (IPCC), which was released on August 30, has brought out some interesting facts about the Himalayan glacier controversy.

Significantly, besides revealing the weaknesses in the multi-layered process established by the IPCC to review draft chapters of its reports and correct errors, the IAC report highlights the shortcomings in the internal process of review within the government when the reports are received by it for comments.

The observation on the Himalayan glaciers in the Fourth Assessment Report (AR4) of the IPCC, issued in 2007, was one of the controversial statements in the report that led the Panel to request the IAC on March 10 to ?conduct a thorough and independent review of the processes and procedures followed by the IPCC in preparing its Assessment Reports.?

The controversial statement on the Himalayan glaciers appeared in Section 10.6.2 of the report of the Working Group II on Impacts, Vulnerability and Adaptation. Citing a 2005 report of the World Wide Fund for Nature (WWF), a non-peer-reviewed (grey) literature, it said: ?Glaciers in the Himalayas are receding faster than in any other part of the world?and, if the present rate continues, the likelihood of them disappearing by? 2035 and perhaps sooner is very high if the Earth keeps warming at the current rate. Its total area will likely shrink from the present 500,000 km2 to 100,000 km2 by ? 2035.?

The WWF report had, in turn, cited a 1999 report of the Working Group on Himalayan Glaciology (WGHG) of the International Commission for Snow and Ice (ICSI) whose chairman at that time was the well-known Indian glaciologist, Syed Iqbal Hasnain, formerly of the Jawaharlal Nehru University (JNU) and now with The Energy Research Institute (TERI), New Delhi. The ICSI report had also resulted in a New Scientist article in June 1999 that quoted Professor Hasnain as saying that the Himalayan glaciers would vanish within 40 years as a result of global warming.

Investigating the error, the IAC committee examined the draft text of the chapter in question and the relevant reviewer comments. The committee's analysis showed that six experts reviewed this section in the first draft and, interestingly, none of their comments was critical. However, at the stage of the second draft, which is sent to both the governments and expert reviewers, two comments were related to the erroneous statement on Himalayan glaciers, but neither of them was from the Indian government or any Indian expert.

David Saltz of the Desert Research Institute, Ben Gunion University, Israel, had pointed to the contradiction in the text, which spoke of glaciers disappearing by 2035, and in the same breath said their total area would shrink by 2035. However, the authors or the review editors ?missed? clarifying this and failed to change the text.

Another reviewer, Hayley Fowler of Newcastle University, questioned the conclusions of the section and referred to the work that arrived at different conclusions. Professor Fowler pointed out that measurements by Hewitt suggested that the western Himalayan glaciers were expanding and added that the changes in precipitation and temperature trends, which he along with D. R. Archer had observed, also supported that. After merely noting on the margins, ?Was unable to get hold of the suggested references; will consider in the final version,? the writing team failed to act upon this comment and the final version of the chapter remained unchanged.

Professor Fowler and Mr. Archer had said in their 2006 paper: ?The observed downward trend in summer temperature and runoff is consistent with the observed thickening and expansion of Karakoram glaciers, in contrast to widespread decay and retreat in the eastern Himalayas. This suggests that the Western Himalayas are showing a different response to global warming than other parts of the globe.?

In contrast to the final version of the WG II report, the final version of the Summary for Policy Makers (SPM), however, does not have any statement on the Himalayan glaciers. This is because the (second) draft version of the report, which is sent to experts and the governments, elicited a response from the Indian government and, interestingly, none from any expert.

The remark included in the draft SPM from Section 10.6.2 was: ?If the current warming rates are maintained, the Himalayan glaciers could decay at very rapid rates, shrinking from the present 500,000 km2 to 100,000 km2 by 2030s.? The Indian government had commented: ?This is a very drastic conclusion. Should have a supporting reference otherwise should be deleted.? In response, the writing team removed the contentious statement from the SPM.

But what is interesting to note here is the lacuna in the review process within the government machinery. While it, or the experts that it had appointed to review, failed to detect the more drastic statement in the main report, it succeeded in raising the flag on the remark included in the SPM. This only means that the review mechanism had failed to scrutinise the voluminous main report but only went through the 20-page summary.