Panel questions IPCC analysis: scientists find discrepancies in global warming

Washington, D.C.- According to the Science and Environmental Policy Project (SEPP), the United Nations has acted on inaccurate data regarding global warming. SEPP claims that documents published by the Intergovernmental Panel on Climate Change (IPCC) have distorted and misinterpreted the scientific evidence that forms the basis for the global climate treaty signed at Rio de Janeiro "Earth Summit"- the U.N. Conference on Environment and Development.

According to an analysis released by SEPP prior to the summit, the 1990 IPCC "Policymakers Summary" which has misled the public into expecting a greenhouse warming catastrophe, is not supported by the full 365-page IPCC Report (1990) or the just-released 200-page Supplement (1992).

In The Greenhouse Debate Continued: An Analysis and Critique of the IPCC Climate Assessment, a panel of climate scientists from Great Britain, Germany, Sweden, New Zealand, Australia, and the United States independently reviewed the three IPCC documents and found numerous discrepancies between them. Major discrepancies include:

• The 1990 "Policymakers Summary" claims that climate warming during the past 100 years is "broadly consistent with predictions of [theoretical] climate models" The 1990 Report and 1992 Supplement, however, present no firm evidence from human-induced greenhouse warming in the climate record.

• The Summary predicts a rapid increase in global temperatures, based on climate model calculations. The Report questions the reliability of current climate models, none of which have been validated by existing climate data.

• The Summary claims to be "certain" that water vapor, the most important greenhouse gas, will "further enhance" any warming effect from human-produced increases in carbon dioxide. The Report stresses the lack of observational data on the distribution of water vapor and on the role of clouds.

The SEPP analysis raises doubts about IPCC claims--put forth in the Foreword to the 1990 Report and in the 1992 Supplement--that the documents had undergone "peer review" prior to their release. The IPCC claim implies a conventional scientific review process in which an editor, independent of the research, enlists scientists to critique a report anonymously. Here, the editors' who were also among the authors, simply circulated the draft to a known group of colleagues, and then accepted or disregarded comments according to their own views. The editors admit to "minority" opinions, which they "have not been able to accommodate." But independent surveys of IPCC scientists demonstrate a substantial majority disagrees with the major assertions of the "Policymakers Summary"--which has been touted as "a international scientific consensus."

The SEPP analysis also points to relevant scientific evidence that has been ignored or down-played by the IPCC. Contrary to IPCC modeling assumptions, for example, the concentration of carbon dioxide (CO2) will increase much more slowly--under realistic scenarios, and with the absorptive effects of oceans and biosphere fully considered--will not double in the next century. Furthermore, recent work shows that the greenhouse gas methane, produced in large part by rice growing and cattle raising, is more important, relative to CO2, than stated in the 1990 Report. Yet proposed control measures emphasize mainly CO2 and focus on limiting the use of energy fuels.

Scientific publications, which suggest that solar effects on climate outweigh human influences, are hardly discussed in the IPCC Supplement. It also ignores geologic evidence pointing to a drop rather than a rise in sea level, as a global warming causes more evaporation and polar ice sheets thicken. There is no evaluation of possible climate effects of high-flying aircraft.

According to Dr. S. Fred Singer, director of the SEPP, the decision to undertake an analysis of the IPCC documents grew out of a 1991 SEPP survey of U.S. participants (contributors and reviewers) in the 1990 IPCC Report. A major finding was their surprising lack of support for the conclusions expressed in the Policymakers Summary. There was certainly no scientific consensus backing the IPCC conclusions, as so often claimed. "The concerns raised by that first survey appear to have been borne out," said Singer. "The IPCC Policymakers Summary is essentially a political document, not a scientific document. It was prepared for and agreed to by the government representatives to the International Panel on Climate Change, and influenced by accredited delegates from other organizations, including environmental pressure groups.

"While energy conservation usually makes economic sense, the proposed climate treaty could lead to costly regulations and controls on energy use and economic development, unsupported by any scientific evidence," Singer continued. "Such drastic policies would put a heavy economic burden on everyone, but have tragic consequences for the poor, both here and abroad."

The Washington-based Science and Environmental Policy Project is an independent research effort to study and document, through publications and symposia, the relationship between scientific data and the development of federal environmental policy.