Precautionary Principle

After the law of supply and demand, there may be no law more difficult to evade than the law of unintended consequences. And there may be no arena in which that law is more pervasive than environmental regulation.

Some years ago, stricter clean-air standards led to the introduction of MTBE, an oxygenation agent that helped engines burn gasoline more completely. Unfortunately, MTBE's high water solubility led to groundwater contamination in many parts of the country. ("An effort to cut air pollution winds up fouling the water," as The New York Times summarized a few years ago.) Federal requirements for reformulated gasoline including MTBE also contributed to regional gasoline price spikes. So eventually Washington decided that ethanol, made from corn, would make a better gasoline blend. Federal ethanol subsidies quickly led to price spikes for food commodities and livestock feed.

Comes now word that the solution to the hole in the ozone layer, hydrofluorocarbons (HFCs) are ferocious contributors to global warming. Industrialized nations turned to HFCs after the 1987 Montreal Protocol banning chlorofluorocarbons (CFCs), which were found to be eating away at the ozone layer, which blocks harmful ultraviolet radiation. But HFCs' ability to trap and retain heat -- the very characteristic that makes them useful in refrigerators and air-conditioners -- also makes them "super-greenhouse gases," capable of trapping as much as 4,470 times as much heat as carbon dioxide. Scientists estimate they account for about 2 percent of America's contribution to climate change.

In recent years some environmentalists have advocated adoption of an ultraconservative doctrine known as the precautionary principle. The precautionary principle stipulates that if a course of action might lead to serious harm, it should be avoided, or strictly controlled, even if the likelihood of the harm is uncertain.

For the most part, progressives have used the precautionary principle as an argument against the introduction of nanotechnology, genetically modified crops, and similar scientific advancements. But the experiences with MTBE, ethanol, CFCs, and HFCs reveal a fatal flaw in the precautionary principle: Even efforts to prevent harm can lead to harm. Since no one can know for sure all possible outcomes of any course of action, the precautionary principle advises against doing anything either way. It is not so much a prescription for precaution as for paralysis. "Don't just do something, stand there" is a decent punchline -- but as a policy guideline, it's (literally) a non-starter.