Endangered Earth Update Now Wait Just a Minute

By EUGENE LINDEN

Since the dawn of the Green movement, critics have argued that environmentalists exaggerate the dangers that humans pose to planet earth and understate the resilience of nature. Historically, the naysayers have had a key influence on policy: they weakened the original Clean Air and Clean Water acts, and Reagan officials James Watt and Anne Burford nearly destroyed the Environmental Protection Agency. But a worsening environment has put the naysayers on the defensive as they struggle to explain ever dirtier air, moribund forests and lakes, oil spills, desertification and the ozone holes over the poles.

Still, while the critics may be down, they are not out. The public may think such issues as the imminence of global warming and the danger of toxic wastes are settled, but scientists do not. Their disagreements about ecological threats make life uncomfortable for the activists, who fear that any apparent uncertainty will give policymakers an excuse for inaction. Critics respond that environmental false alarms have produced bad policy. While some naysayers are economists, industrialists and bureaucrats who view environmentalism as an irrelevant disruption of the real business of the world, others are sophisticated scientists who maintain that the U.S. should not risk its economic security to prepare for ecocatastrophes that might never come to pass.

One formidable contrarian is Bruce Ames, a biochemist at the University of California, Berkeley. He contends that obsessive concern with cancer-causing chemicals in foods, pesticides and toxic wastes has produced a regulatory tangle at EPA and a superfluous Superfund to clean dump sites. Government restrictions on man-made chemicals are absurdly stringent in proportion to ; their risk, says Ames. He notes that while the public panicked last spring because of trace amounts of the synthetic growth regulator Alar found on apples, many fruits contain natural carcinogens in concentrations 1,000 times as great. Observes Ames: "Eating vegetables and lowering fat intake will do more to reduce cancer than eliminating pollutants."

Ames is a tough target for environmentalists because he devised the test that is used to determine whether chemicals are carcinogenic. Nonetheless, Janet Hathaway of the Natural Resources Defense Council argues that talk about natural carcinogens deflects attention from industry's responsibility for environmental risks. Ames, she says, exaggerates levels of natural toxins and understates the exposure to and effect of synthetic chemicals.

Another area of contention is global warming, which scientists fear could cause disruptive changes, such as a rise in sea levels. NASA official James Hansen told Congress last year that he believed the greenhouse effect had already arrived. Since then, that assertion has been widely challenged.

Among the most respected critics is Andrew Solow, a statistician at the Woods Hole Oceanographic Institution's Marine Policy Center in Massachusetts. Solow asserts that the computer models used to predict the greenhouse effect are so weak that they cannot even account for the modest 0.5 degrees C warming that has occurred over the past 100 years. "We all believe in the physics of the greenhouse effect," says Solow, "but to say almost anything about timing, the magnitude of change or its geographic distribution is more than we can do."

The scientist believes lack of computing power -- as well as ignorance about such critical factors as the interactions between the oceans and the atmosphere, and the impact of clouds on surface temperatures -- limits the ability to predict the greenhouse effect. "It's possible that Washington will see 96 days of temperatures over 100 degrees F in the year 2010," he says, "but it's also possible that the U.S. will be economically impoverished because it unilaterally imposed draconian measures in anticipation of a greenhouse warming that never arrived."

Stephen Schneider of the National Center for Atmospheric Research responds that waiting for absolute certainty about global warming will produce many years of policy paralysis. Thomas Lovejoy of the Smithsonian Institution agrees, noting that societies may pay a price for doing nothing that outweighs ) the expense of prudent preparation. While the world hailed the 1987 Montreal Protocol, designed to reduce chlorofluorocarbon output, the destruction of the ozone layer continued to accelerate because of CFCs already in use. Atmospheric chemist Sherwood Rowland of the University of California at Irvine is worried that similar delays in dealing with global warming will produce a treaty that is "a perfect autopsy."