As United Nations negotiations for the Global Climate Convention convene this month, scientists on the UN's panel of expert advisers are under fire for altering a scientific report. The Intergovernmental Panel on Climate Change (IPCC) made headlines with its claim that "the balance of evidence suggests a discernible human influence on global climate." Now there is evidence suggesting that this assessment was driven by politics, and not science.
The IPCC's 1995 report, the final version of which was published in June, is supposed to represent the consensus of world scientific experts regarding the highly controversial issue of global warming. The panel's work is relied upon by Global Climate Convention negotiators who are considering possible curbs on the use of fossil fuels, such as energy taxes. The IPCC's reputation for objectivity rests upon its commitment to balanced scientific opinion arrived at through the process of peer review.
Potential misconduct at the IPCC was recently uncovered by the Global Climate Coalition, an association of oil, coal, and utility companies. In a memorandum to Congress and the White House, the business coalition alerted U.S. officials that the IPCC's final published report had been altered before final publication. Substantial portions of Chapter 8, which discusses the impact of human activities on the earth's climate, had been re-written by one of its authors after contributing scientists had already given their approval. Cautionary references to scientific uncertainty were removed or modified, changes not approved by the reviewers. [Excerpts are printed nearby.] Writing in the Wall Street Journal, former president of the National Academy of Sciences Frederick Seitz called the last-minute editing a "disturbing corruption of the peer review process" which could "deceive policymakers and the public into believing that the scientific evidence shows human activities are causing global warming."
Seitz's remarks set off tremors throughout the scientific community. Several articles about the controversy appeared in the New York Times and Energy Daily, as well as the prestigious journals Science and Nature. The IPCC's Sir John Houghton labeled the charges "appalling," and maintained that the re-write "improved the science." Lead author Ben Santer, an atmospheric scientist at the Lawrence Livermore National Lab, denied wrongdoing and claimed that IPCC rules allow modifications "to improve the report's scientific clarity." However, the deletions were more than minor clarifications. Key portions accepted by contributing scientists were later removed or altered without their knowledge. The changes functioned to suppress doubts and to downplay uncertainties about forecasting a human influence on climate. For example, Santer told Science that in a discussion of when scientists will be able attribute climate change to human causes, he removed the phrase "we do not know" because it overstated doubts that human activity can be blamed.
The IPCC's explanations bolster the impression that the revisions were politically motivated. Santer cites a November State Department memo to the IPCC advising "that chapter authors modify the text in an appropriate manner." According to an editorial in Nature, IPCC officials said that revisions to the text were needed "to ensure that it conformed to a 'policymakers' summary of the full report," a document whose language is voted on by government delegates. Thus the process is heavily influenced by government officials, including non-scientists.
The IPCC had a rather different response to earlier efforts to modify its report. During peer review, Britain's Global Commons Institute (GCI) took issue with a finding in Chapter 6 that the costs of reducing greenhouse gas emissions may exceed the predicted economic damage from global warming. Demanding that the damage be calculated in a way which showed that richer countries owe "compensation" to the Third World, GCI orchestrated an effort by delegates from Cuba and the Alliance of Small Island States to rewrite the report, replacing all damage estimates with warnings about "the loss of unique cultures." In response, senior IPCC official James Bruce insisted that the proper time to make revisions under IPCC rules was during two prior rounds of peer review: "At this stage [the October 1995 Montreal working group], the authors can make a few editorial changes for clarity of reading, but not changes to the meaning or substance of the report" (Emphasis added).
Perhaps IPCC officials should consult one another regarding their contrasting interpretations of IPCC procedures. Both environmentalist groups, like GCI and Greenpeace, and industry groups like the Global Climate Coalition, are having great difficulty understanding how the IPCC conducts itself with regard to peer review. What is clear, however, is that the UN panel is so thoroughly politicized that its integrity and objectivity cannot be taken for granted.
--James M. Sheehan