The National Academy of Sciences’ National Research Council just released a report that basically says temperatures are rising, but we aren—t sure who to blame, while uncertainties in science make predictions of future climate conditions tentative at best. Unfortunately, politicians and journalists somehow missed everything except “temperatures are rising” in the “Climate Change Science: an Analysis of Some Key Questions” report.
“Panel Tells Bush Global Warming Is Getting Worse,” screamed the New York Times.
“NAS Tells Bush Global Warming is Real Problem,” shouted the Washington Post.
Both articles go on to observe that these new dire predictions might cause President Bush to re-think his position on climate change. Phil Clapp, president of the National Environmental Trust, tells the New York Times, “The president can no longer wiggle out of aggressive action by arguing that the science is inconclusive.” The Post quotes John Kerry (D-Mass) as saying, “The report underscores . . . the full measure of the vacuum in the administration’s leadership on this issue.”
But statements from within the NAS report make one wonder if any of these people bothered to read the slim 24-page report before calling a press conference or filing their stories.
The very first page of the NAS report says, “Because there is considerable uncertainty in current understanding of how the climate system varies naturally and reacts to emissions of greenhouse gases and aerosols, current estimates of the magnitude of future warming should be regarded as tentative and subject to future adjustments upward or downward.” That—s not exactly what any rational person would call an unequivocal affirmation that global warming is a well-defined threat.
The authors of the report are not even sure that you can blame global warming on humans. The report states that “A causal linkage between the buildup of greenhouse gases in the atmosphere and the observed climate changes during the 20th century cannot be unequivocally established.” The statements made in the NAS report are so contrary to the conventional views of manmade climate change that headlines should have read, “NAS panel says humans may not be causing global warming!”
And while the NAS report observes that climate models have many uses, they also observe that climate models are far from perfect. They note that the simulation ability of such models is limited by “uncertainties in their formulation, the limited size of their calculations, and the difficulty of interpreting their answers that exhibit almost as much complexity as in nature.” Predictions of future climate rest on a raft of assumptions, such as those projecting future fossil fuel and land-use changes that can affect the concentration of CO2 and other gases and aerosols. But these are exactly the areas, according to the NAS, where the science is weakest. The NAS authors point out that there are large uncertainties in underlying assumption about “population growth, economic development, life style choices, technological change and energy alternatives” used in predicting future climate conditions.
Perhaps the most egregiously under-reported aspect of the NAS report is the first “mainstream” acknowledgement that the landmark reports of the United Nations Intergovernmental Panel on Climate Change (IPCC) are significantly influenced by governmental officials and policy makers, and are not the purely scientific work of “2,000 scientists.” Not only does the NAS reveal that the authors of the IPCC report are invited to participate by governmental representatives and tend to be disproportionately non-American, the NAS observes that governmental representatives are full partners in writing the “Summary for Policymakers” of the landmark IPCC reports. Stunningly, the NAS report confirms previously contested charges that the technical reports are retroactively modified in order to make them match the politically derived summary. Finally, the NAS points out that the “Summary for Policymakers” tends to downplay uncertainty, and admonishes that information about the confidence and probability of various predictions should always be included and looked at carefully, even in political summaries. Without such information, the Academy says, “…the IPCC Summary for Policymakers could give an impression that the science of global warming is “settled,” even though many uncertainties still remain.”
The 11-member panel of the NAS calls for an ambitious research agenda to address the remaining uncertainties of global warming science. They also give marching orders to American scientists: “The most valuable contribution U.S. scientists can make,” the NAS says, “is to continually question basic assumptions and conclusions, promote clear and careful appraisal and presentation of the uncertainties about climate change as well as those areas in which science is leading to robust conclusions, and work toward a significant improvement in the ability to project the future.”
Dr. Kenneth Green is senior fellow at Reason Foundation and Chief Scientist at Frasier Institute.