---
title: "Criticism of the IPCC Fourth Assessment Report"
chunk: 3/5
source: "https://en.wikipedia.org/wiki/Criticism_of_the_IPCC_Fourth_Assessment_Report"
category: "reference"
tags: "science, encyclopedia"
date_saved: "2026-05-05T04:22:45.688900+00:00"
instance: "kb-cron"
---

"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 (see table: Receding rivers of ice).
The question of whether it was acceptable to use material which had not been peer reviewed has been disputed. IPCC rules permit the use of non-peer-reviewed material, subject to a procedure in which authors are to critically assess any source that they wish to include, and "each chapter team should review the quality and validity of each source before incorporating results from the source into an IPCC Report."
The official statement issued by the IPCC on 20 January 2010 noted that "a paragraph in the 938-page Working Group II contribution to the underlying assessment refers to poorly substantiated estimates of rate of recession and date for the disappearance of Himalayan glaciers. In drafting the paragraph in question, the clear and well-established standards of evidence, required by the IPCC procedures, were not applied properly." It emphasised that the paragraph did not affect the conclusion in the final summary for policymakers in the 2007 report, which it described as "robust, appropriate, and entirely consistent with the underlying science and the broader IPCC assessment", and reaffirmed a commitment to absolute adherence to the IPCC standards. The IPCC also stated that it did not change the broad picture of man-made climate change. This was confirmed by Wilfried Haeberli, who announced the latest annual results of the World Glacier Monitoring Service. He stated that the important trend of 10 years or so showed "an unbroken acceleration in melting" and on expected trends, many glaciers will disappear by mid century. Glaciers in lower mountain ranges were the most vulnerable, and while those in the Himalayas and Alaska could grow in the short term, in a realistic mid-range warming scenario they would not last many centuries. Mojib Latif, a climate scientist who contributed to the report of Working Group 1, sees the consequences of the glacier data mistake but also the need to continue focusing on global warming.

=== African crop yield projections ===
Chapter 9 of the Working Group II report states that "In other countries, additional risks that could be exacerbated by climate change include greater erosion, deficiencies in yields from rain-fed agriculture of up to 50% during the 2000–2020 period, and reductions in crop growth period (Agoumi, 2003)."  This claim was also included in the AR4 Synthesis Report, and has been mentioned in speeches by IPCC Chairman Rajendra Pachauri and UN Secretary-General Ban Ki-moon.  The source cited in the report for this claim is a non-peer reviewed policy paper published by International Institute for Sustainable Development, a Canadian think tank.  Chris Field, the new lead author of the IPCC's climate impacts team, questioned the claim, telling the Sunday Times that "I was not an author on the Synthesis Report but on reading it I cannot find support for the statement about African crop yield declines".  Former IPCC chairman Robert Watson said "Any such projection should be based on peer-reviewed literature from computer modelling of how agricultural yields would respond to climate change. I can see no such data supporting the IPCC report."
The United States Environmental Protection Agency used the IPCC report on this point, and received criticism that because of the nature of the source, they should not have done so. The EPA rebutted this criticism, noting that "The IPCC statement cites a report by Dr. Ali Agoumi... These vulnerability studies were prepared under the U.N. Environment Programme Global Environment Fund and included in the National Communications of these three countries to the U.N. Framework Convention on Climate Change (Ministry of Territory Development and Environment, 2001, Kingdom of Morocco, 2001 and Republic of Tunisia, 2001)... Dr. Coleen Vogel, a contributing lead author of the IPCC chapter on Africa impacts... explained that Agoumi's report received rigorous scrutiny by her fellow authors and was thoroughly discussed during development of the chapter... The process described by Dr. Vogel is consistent with the IPCC's guidance on the use of gray literature".