In a chapter on climate change impacts in Asia, the Intergovernmental Panel on Climate Change’s Fourth Assessment Report (2007) relied on an error-riddled online article when it discussed the likely state of Himalayan glaciers in 2035. It did so despite questions raised by some reviewers. Details about the incident have come to light since early November when the Indian government published a report that contradicted the IPCC. The error and the IPCC’s initial response highlight the need to strengthen the IPCC review process, and its capacity to respond quickly and appropriately to such problems. Failure to do so may undermine public confidence in the IPCC and invite opportunistic attacks by those opposing meaningful action on climate change.

Updates — See related posts:

February 5: Questions to an IPCC co-chair on ensuring the credibility of IPCC leadership and communications
January 21: Worldwide glacier melt a real concern; Himalaya controversy leaves questions about IPCC leadership
February 12: World Wildlife Fund statement on the IPCC and WWF’s scientific work

What the IPCC Working Group II Said About Himalayan Glaciers — and Where the Information Came From

In 2007, the Intergovernmental Panel on Climate Change (IPCC) published the following statement in its Fourth Assessment Report:

“Glaciers in the Himalaya are receding faster than in any other part of the world (see Table 10.9) 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 warming at the current rate. Its total area will likely shrink from the present 500,000 to 100,000 km2 by the year 2035 (WWF, 2005).”

The statement appeared in the volume produced by Working Group II (Impacts, Adaptation, Vulnerability) of the IPCC, in the discussion of The Himalayan glaciers of Chapter 10 (Asia) (section 10.6.2). In support of the statement, the IPCC referenced a report from the World Wildlife Fund (WWF) published in 2005.

However, the statement in fact came nearly verbatim from an article titled “Glaciers Beating Retreat,” in an online publication called Down to Earth published on 30 April 1999. [UPDATE: Information available as of January 21 indicates that the author of the article was Mridula Chettri.] It said (highlighted text is identical to IPCC text):

“Glaciers in the Himalaya are receding faster than in any other part of the world and, if the present rate continues, the likelihood of them disappearing by the year 2035 is very high,” says the International Commission for Snow and Ice (ICSI ) in its recent study on Asian glaciers. “But if the Earth keeps getting warmer at the current rate, it might happen much sooner,” says Syed Iqbal Hasnain of the School of Environmental Sciences, Jawaharlal Nehru University, New Delhi. Hasnain is also the chairperson of the Working Group on Himalayan Glaciology (WGHG), constituted in 1995 by the ICSI. “The glacier will be decaying at rapid, catastrophic rates. Its total area will shrink from the present 500,000 to 100,000 square km by the year 2035,” says former ICSI president V M Kotlyakov in the report Variations of snow and ice in the past and present on a global and regional scale.

There were several problems with the Down to Earth piece. First, the ICSI Report on Himalayan Glaciology – which was written by Syed Iqbal Hasnain — in fact did not say “Glaciers in the Himalaya are receding faster than in any other part of the world and, if the present rate continues, the likelihood of them disappearing by the year 2035 is very high.” Furthermore, the report by Kotlyakov (Variations of Snow and Ice in the past and at present on a Global and Regional Scale [1996]) referred to all glaciers outside the polar regions (not just in the Himalayas) and more importantly referred to 2350 – not 2035; and it specifically said glaciers will survive in the Himalayas even then. Here is what Kotlyakov wrote:

“The extrapolar glaciation of the Earth will be decaying at rapid, catastrophic rates— its total area will shrink from 500,000 to 100,000 km² by the year 2350. Glaciers will survive only in the mountains of inner Alaska, on some Arctic archipelagos, within Patagonian ice sheets, in the Karakoram Mountains, in the Himalayas, in some regions of Tibet and on the highest mountain peaks in the temperature [sic] [temperate] latitudes.”

The IPCC repeated some of the information from the Down to Earth 1999 article elsewhere in its assessment report, most notably in the Technical Summary for the Working Group II report. Box TS-6 says:

If current warming rates are maintained, Himalayan glaciers could decay at very rapid rates, shrinking from the present 500,000 km2 to 100,000 km2 by the 2030s. ** D [10.6.2]

The double asterisks are supposed to indicate “high confidence.”

Some IPCC Reviewers Raised Questions about the Assertions

IPCC reports are subject to a very extensive and well documented review process. This reduces, though does not eliminate, the likelihood of serious errors. The review drafts and comments are available online, and show that questions were raised about the statements during the review process.

In response to a “second order” review draft of chapter 10 (May 2006) , David Saltz of the Desert Research Institute at Ben Gurion University commented on the sentence “ Its total area will likely shrink from the present 500,000 to 100,000 km2 by the year 2035.” He asked ” What does ‘its’ refer to?” and noted the contradiction between that sentence and the previous one that said there was a “very high” likelihood that the glaciers would disappear by 2035 — or sooner. “100,000? You just said it will disappear,” he wrote.

The Japanese Government raised concerns about both sentences, neither of which at that point were associated with any reference.“This seems to be a very important statement,” it said. “What is the confidence level/certainty? (i.e.“the likelihood of the glaciers disappearing is very high” is at which level of likelihood? ref. to Box TS-1, “Description of Likelihood”). Also in this paragraph, the use of “will” is ambiguous and should be replaced with appropriate likelihood/confidence level terminology.” Despite the questions, the statements were retained in the final published version of Chapter 10, though the authors did finally add a reference — not to the Down to Earth article from which it was drawn, but to a 2005 report from WWF Nepal: An overview of glaciers, glacier retreat, and subsequent impacts in Nepal, India and China.

IPCC assessments include a Technical Summary (TS) and a Summary for Policymakers (SPM) for each of the three working group volumes. The “second order” review draft of the SPM for the Working Group II volume said “If current warming rates are maintained Himalayan glaciers could decay at very rapid rates, shrinking from the present 500,000 km2 to 100,000 km2 by the 2030s.” Here too, questions were raised. The Indian Government commented: “This is a very drastic conclusion. Should have a supporting reference otherwise need to be deleted.” The statement in this case was deleted. But the second order draft of the Technical Summary contained a nearly identical statement. No comments were made on that sentence and it survived in Box TS-6 of the final Technical Summary (see exact text above).

The IPCC Working Group I Report Did Not Make the Same Claims

The expertise on glaciers within the IPCC largely resides in Working Group I (The Physical Science Basis) — not in Working Group II. Working Group I said nothing about Himalayan glaciers disappearing; nor did it provide any estimate of the areal extent of Himalayan glaciers in 2035. What it did say is:

  • “In the climate system, the cryosphere (which consists of snow, river and lake ice, sea ice, glaciers and ice caps, ice shelves and ice sheets, and frozen ground) is intricately linked to the surface energy budget, the water cycle, sea level change and the surface gas exchange. The cryosphere integrates climate variations over a wide range of time scales, making it a natural sensor of climate variability and providing a visible expression of climate change. In the past, the cryosphere has undergone large variations on many time scales associated with ice ages and with shorter-term variations like the Younger Dryas or the Little Ice Age (see Chapter 6). Recent decreases in ice mass are correlated with rising surface air temperatures.”
  • “Mass loss of glaciers and ice caps is estimated to be 0.50 ± 0.18 mm yr–1 in sea level equivalent (SLE) between 1961 and 2004, and 0.77 ± 0.22 mm yr–1 SLE between 1991 and 2004. The late 20th-century glacier wastage likely has been a response to post-1970 warming. Strongest mass losses per unit area have been observed in Patagonia, Alaska and northwest USA and southwest Canada. Because of the corresponding large areas, the biggest contributions to sea level rise came from Alaska, the Arctic and the Asian high mountains.”
  • “Whereas glaciers in the Asian high mountains have generally shrunk at varying rates…, several high glaciers in the central Karakoram are reported to have advanced and/or thickened at their tongues (Hewitt, 2005), probably due to enhanced precipitation.”

IPCC Lapses

Though the IPCC process for the most part functions well and has produced scientifically credible assessments, this situation clearly suggests errors nevertheless occur. Lifting text from a publication (Down to Earth) and attributing it to another source (WWF, 2005) is unacceptable under any circumstances. To do so with text that the Japanese government correctly termed “a very important statement” compounds the problem. Using text that is not peer-reviewed and is riddled with errors adds insult to injury. The IPCC review process should catch such problems. But apparently no external reviewers flagged the problematic text in the Technical Summary; and while reviewers raised questions about Chapter 10, the authors did not respond appropriately. This begs for an explanation.

The situation also raises questions about communications and coordination between authors of different parts of the Working Group II report. While the Indian Government objected to the text in the Summary for Policymakers — and the text was dropped — were its objections relayed to the authors of the Technical Summary and Chapter 10? Similarly, were concerns expressed by reviewers of Chapter 10 relayed to the authors of the Technical Summary?

Finally, the incident raises questions and concerns about interactions between Working Group I and Working Group II. There is nothing in the Working Group I report that supports the Working Group II claims about the disappearance of Himalayan glaciers by 2035; or to support the other assertion about the glaciers declining from 500,000 to 100,000 km2 by the year 2035. This suggests insufficient coordination between Working Groups.

The IPCC Response

Since the IPCC issued its Fourth Assessment Report in 2007, questions have been raised about the claim that the Himalayan glaciers would disappear by 2035. When the Indian government issued a report in early November 2009 (Himalayan Glaciers, A state-of-art review of glacial studies, glacial retreat and climate change ) that contradicted the claim, the questions became more persistent. The initial response of IPCC chairman Pachauri was dismissive. We and others have investigated and the story outlined above has emerged.

Following the reference provided by the IPCC report, those searching for the scientific basis of the IPCC statement looked into the WWF report. The WWF report cited New Scientist, pulling it too into the fray. Most have incorrectly concluded that New Scientist was the ultimate source of the IPCC statement when in fact the source very clearly is the Down to Earth piece. The New Scientist article, “Flooded Out – Retreating glaciers spell disaster for valley communities” was published on 5 June 1999 issue, more than two months after the Down to Earth article. Nevertheless, without a public explanation from the IPCC, both WWF and New Scientist have been targeted for criticism.

New Scientist has been compelled to respond, first with an article on the controversy (Debate heats up over IPCC melting glaciers claim, 11 January 2010) and then with an editorial (Sifting climate facts from speculation, 13 January 2010) that draws more attention to the controversy. Referring to Hasnain’s 1999 assertions about Himalayan glaciers, New Scientist asks “how could such speculation have become an IPCC `finding’ which has, moreover, recently been defended by the panel’s chairman? We are entitled to an explanation, before rumour and doubt compound the damage to the image of climate science already inflicted by the leaked `climategate’ emails.”

The IPCC should have swiftly investigated. Had it done so, it would have quickly determined that the text was lifted verbatim from Down to Earth (not WWF or New Scientist) and that it was scientifically indefensible. That then should have led to a public acknowledgement, along with a commitment to issue a correction, to investigate the underlying circumstances, and to implement any needed reforms. Without an appropriate and coherent response from the IPCC, the problem has festered amidst considerable confusion. Climate change denialists meanwhile are capitalizing on the situation, threatening to undermine public confidence in the otherwise strong scientific assessments produced by the IPCC.

Finally, nearly two months after the controversy erupted, IPCC chairman Rajendra Pachauri today (18 January 2010) indicated that the IPCC was reviewing the situation.

What Next?

Above all, it is important to keep this problem in perspective. IPCC reports are massive undertakings involving thousands of scientists, thousands of pages and thousands of references. It is a testament to the process and the participating scientists that so few serious problems develop. This specific problem involving several sentences and one reference does not significantly alter the broad and solid scientific basis for action on climate change. Nevertheless it is important that the IPCC quickly, clearly and publicly acknowledge and characterize the problem. It then should initiate the process of correcting that specific error. But more is called for. To begin with, the handling of this incident so far by the IPCC leadership, especially the dismissive initial response to external criticism by IPCC chairman Pachauri, raises concerns that call for further discussion. In addition, IPCC review procedures should be examined to determine whether changes are needed to prevent this kind of problem from arising with future reports.