February 7, 1990 | Executive Memorandum on Energy and Environment
or 4 degrees. Example: Estimates of potential sea level rise have been reduced from an average of three feet down to one foot. And these estimates undoubtedly will be adjusted in the coming years. One way of checking a computer model is to feed it data and ask it to predict a result that already is known. This has been done with the models that are used to predict future warming. The result: When fed information corresponding to the conditions existing in the late 19th century, the computer models "predict" that today's climate should be far hotter than it actually is. The lesson here is that these computer models are not yet ready to be a guide for making policies or passing laws. There is even evidence indicating that the atmosphere is cooling. A study by University of Virginia Professor of Environmental Science Patrick Michaels, for instance, finds that from 1918 to 1958 there were only five winters during which outbreaks of arctic air swept as far as the Southeastern United States. Since 1958, however, this has happened in 21 of the 31 winters. Because of a general global cooling trend from the 1940s through the 1960s, many scientists even were predicting the advent of another ice age. Records of temperature trends in the U.S., moreover, give no indication of a warming trend. Meteorologist Thomas Karl of the National Climatic Data Center headed a 1988 study that finds 61no, statistically significant evidence of an overall increase in annual temperature or change in ann u al precipitation for the contiguous U.S. [between] 1895-1987." Marshalling the Facts. In light of the uncertainty concerning the degree of global warming and the inaccuracy of predictions made only two years ago, it is very premature to propose policies t h at would restrict severely the burning of fossil fuels. Such policies, after all, would impose huge costs on all Americans and on American living standards and competitiveness. They would shut many American factories, throw great numbers out of work, and r aise the cost of production and of fuel for every factory and household. Rather than rush into such policies, the U.S. must give scientists more time to marshall the facts, conduct more accurate studies, and make more accurate projections. If policy maker s had acted on the inaccurate predictions of two years ago, economically costly policies would be in place dealing with a crisis that is now known to be only half as serious as originally thought. Beyond waiting for better data, policy makers must begin di s cussing how to establish priorities among competing needs of society. Even if a problem exists, policy makers owe it to the public to prescribe solutions that do the least damage to employment and living standards. Bush in his recent speech spoke of the n eed to match policy commitments to emerging scientific knowledge and to reconcile environmental protection with economic development, This is a wise and prudent approach, cool-headed advice for the global warming debate. Kent Jeffreys Policy AnalystF or further information: Warren T. Brookes, "The Global Warming Panic," Forbes, December 25,1989. William Booth, "New Models Chill Some Predictions of Severely Overheated Earth," 7he Washington Pos4 January 29,1990.