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GUEST EDITORIAL
Global experiment ntis is ajne mess you’ve gotten us into now, Stanley. -Oliver Hardy In retrospect, I doubt that even the lovably inept Stan Laurel could have bungled his way into the scale of mess that is unfolding as part of the planetary climate change induced by anthropogenic trace gas emissions into our atmosphere. What began as a scientific curiosity has rapidly moved through phases of broader scientific discussion and argument to cold incredulity. Most of us have heard parts of the scientific story. Ambient atmospheric measurements at Mauna Loa Observatory have established that the C02 concentration rose from 315 ppm in 1958 to around 340 in 1985. Ten or 15 years ago, the suggestion of an increase in atmospheric C q was interesting, but relatively few scientists were worried. The National Academy of Sciences prepared two splendid reports that authenticated the climate threat and dutifully described the kinds of scientific uncertainty regarding the extent and timing of any climate change. These studies concluded that climate change would likely occur in the next 100 years as a result of a doubling of the COz concentration by the year 2070. The scientific evidence has continued to build, however, and now constitutes an awesome basis for predictions of world impact. Due to increases in other trace gases, the time of effective C02 doubling has been reduced to 2030, with significant climate change occurring as early as 1990. We know that the greenhouse effect is contributed to by many anthropogenic gases ( C q , NzO,C h , CO, HzO,and chlorofluorocarbons) that absorb infrared radiation as the Earth emits energy back to space. It is not just the greenhouse effect that is of concern, however. We know that we are causing modificationsto stratospheric composition and ozone chemistry by introducing ozone-depleting chlorofluorocarbons, which continue to increase globally despite a U.S. ban on the use of Freons in aerosol cans. We know that tropospheric chemistry is being modified by increasing levels of CO and C b . We understand that these are not individual problems, but are perturbations of a single global system of atmospheric cycles. Most important, we believe that the Earth’s heat balance is extremely M)1~936wBB1092D041~1.~ 0 1986 American Chemical Sociely
sensitive to these changes. We know these things now, but who is listening? More than 80 scientists from 29 countries met in Villach, Austria, in October 1985 under the sponsorship of the World Meteorological Organization, the United Nations, and the International Council of Scientific Unions. This group issued a warning about climate warming in the next decades. The group stated that the trend would be greater than any in man’s history, and it called for governments and international agencies to increase public education efforts and to take the impending changes into account in their policies for social and economic development. We may not be able to do anything now about the changes over the next decade or two, but the rate and overall extent of the warming could be affected by serious attention to energy conservation, care in the use of fossil fuels, and limits on the emission of greenhouse gases. In a world that has every square inch of its surface locked into political boundaries, this is a tall order. World political decisions do not have to consider wholesale changes in agricultural productivity or the availability of land due to the level of the seas. In my opinion, short of nuclear warfare, the coming climate changes are the greatest problems we must face in the immediate future.
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North Caro/ina at Chapel Hi//. His research specialry is atmospheric chemistry, particularly ozone and smog chemistry He W(IS recently the c h a i r m of an EPA workshop designed to introduce policy W e r s to atmospheric trace gas issues. Envimn. Sci. TBdmol.. MI. 20. No. 5.1986 41s
