UN Climate Change Report Deeply Flawed, Scientist Says Bias, imprecision faulted

Published October 1, 1997

As the Clinton administration moves forward with a massive public relations campaign to win support for a global warming treaty, a prominent scientist has thrown cold water on the UN-sponsored report that serves as the foundation for the White House’s agenda.

The report, issued by the Intergovernmental Panel on Climate Change (IPCC) and known as Climate Change 1995, “fails to find evidence of significant or harmful climate change resulting from human activities” and “provides no evidence to support drastic economically damaging measures to control greenhouse gas emission,” according to Dr. Vincent Gray, a widely published New Zealand scientist who serves on the IPCC peer review panel.

Gray’s evaluation of Climate Change 95 is contained in a report recently released by The Heartland Institute. Titled “Climate Change 95: An Appraisal,” Gray’s report is the most comprehensive analysis of the often-quoted, often-misunderstood 572-page IPCC document.

Though it is full of scientific data, Gray writes, Climate Change 95 “presents this information in a disturbingly imprecise and sloppy form.” “Disentangling the bias, absence of precision, and special pleading is difficult,” he adds. The IPCC report’s use of unscientific terms explains, according to Gray, why the document has been badly misinterpreted by those unfamiliar with the terminology of climatology.

“This lack of precision,” he points out, “makes it easier to exaggerate the extent of climate change, and to claim unjustified agreement of climate data and computer models.”

Gray evaluates in detail the report’s greenhouse gas science, finding that “estimates of emissions and concentrations of carbon dioxide, methane, and nitrous oxide all are slanted to support exaggerated climate trends.” Several graphs included in Gray’s analysis document how Climate Change 95 “diverges from real science on these issues.” For example, Gray notes, the IPCC assumes that starting in the year 1990, carbon dioxide concentrations in the atmosphere will increase by 1 percent per year–a figure 2-1/2 times the measured rate of carbon dioxide increases in the 1980s and 1990s.

The New Zealand scientist also accuses the Climate Change 95 authors of relying on computer models whose results do not comport with actual temperature trends. The IPCC acknowledges that surface temperature measurements are subject to error, yet nevertheless rejects more accurate temperature measurements taken by radiosonde (weather balloon instruments) and NASA satellites. This is disturbing, according to Gray, because “there appears to be no evidence of a global temperature trend over the past 27 years if the radiosonde measurements are considered, or over 18 years if satellite measurements only are considered.”

As for the IPCC report’s much-quoted pronouncement that “the balance of the evidence suggests a discernable human influence on the climate,” Gray is dismissive. “Humans are undoubtedly influencing the climate,” he acknowledges. “The important point, though, is whether the influence is significant, and whether it matters.”

“There is nothing in any of the IPCC reports to support the claim that human activity has a harmful effect on the climate,” Gray states without reservation.

“When bias is discounted,” he concludes, “Climate Change 95 provides no evidence to support drastic or economically damaging measures to control greenhouse gas emissions. If current climate and economic trends continue, global warming over the next century is unlikely to be above 1 degree C.”

PF: “Climate Change 95: An Appraisal,” by Dr. Vincent Gray, is available through PolicyFax. Call 847/202-4888 and request documents ##2329313 (executive summary, 6 pages); #2329424 (part 1, 10 pages); and #2329425 (part 2, 13 pages). The document is also available on the World Wide Web at http://www.heartland.org/gray-sum.htm.