A continuing source of national embarrassment in the United States should be our inability to produce politicians, bureaucrats, and news commentators who are capable of truthfully reading simple graphs of temperature vs. time. Instead, the country is rushing headlong toward global warming treaties that will sharply reduce hydrocarbon use and thereby cause trillions of dollars in economic dislocations and great concomitant human suffering and death. Figure 3, republished in "Global Warming Costs for the U.S.'' Brief No. 213 (September 1996) by the National Center for Policy Analysis, 12655 N. Central Expy., Suite 720, Dallas, TX 75243-1739, from a 1990 Oak Ridge National Laboratory report, shows the range of average annual temperatures in the U. S. during the past century. The range from high to low is approximately 2.4° C. Omitting extremes, most of these averages lie in a range of about 1.5° C. The global warmers claim that temperatures during the past decade
"Spurious Trends in Satellite MSU Temperatures from Merging Different Satellite Records'' by J. W. Hurrell and K. E. Trenberth in
Nature 386, pp 164-167 (1997), shows the current state of this debate.Satellite measurements since 1979 have shown a gradual
decrease in atmospheric temperature of - 0.11° C per decade, while surface temperatures are claimed to have increased by 0.10° C per decade. The satellite data is more reliable, since ground measurements are susceptible to the local effects of human activity.Ordinary variations in temperature are, however, so much greater than either of these measurements that the only sensible conclusion is that no significant temperature change has been detected. Even though the "dreaded'' atmospheric carbon dioxide level has already risen substantially, the only apparent effect of this rise has been increased growth rate of trees and other plants - surely not an undesirable result.
Hurrell and Trenberth suggest that the discrepancy between atmospheric and ground measurements can be attributed to satellite calibration errors during transitions between satellites. Specifically, they conclude that a + 0.23° C adjustment in the atmospheric record should be made before July 1981 and a - 0.12° C adjustment should be made after August 1991. This would give an atmospheric temperature change of (0.35 - 0.18) / 1.6 = + 0.10° C per decade. (The authors state that these changes produce a "small positive trend'' in atmospheric temperature, but they do not give a value for this trend. We have assumed that the signs of their suggested adjustments should be thusly interpreted, although they seem to suggest an opposite result.)< /FONT >
Comparison with the U. S. temperature fluctuations in Figure 3 shows that this value of 0.1° C is so low as to probably be irrelevant to human affairs and environmental quality. Moreover, it has not been shown that this tiny change is any more than an ordinary natural variation that is unrelated to human activities.
It is reasonable to suggest that rising carbon dioxide levels might cause an increase in temperature and that a few one-hundredths of a degree rise may already have taken place as a result. It is unreasonable, however, to assume that this is true without experimental verification and to claim that any such rise will be harmful to the environment. If 0.10° C were added to the graph in Figure 3 between the years 1990 and 2000, would you consider that alarming?
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Vol. 24, No. 9
Newsletter: Access to Energy Newsletter Archive Volume: Issues Issue/No.: Vol. 24, No. 9 Date: May 01, 1997 01:10 PM (For actual publication date see newsletter.) Title: Science and Humility
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