Zambia and Zimbabwe are not alone. The European Union also cites the precautionary principle as a basis for resisting the importation of genetically modified foods and adopting new international environmental measures. More and more, environmental policy incorporates this "precautionary principle," which calls upon governments to impose regulatory measures based upon the barest potential of environmental harm. If a chemical substance might be causing harm, it should be controlled or eliminated. If a new technological innovation could have unknown environmental effects, it should not be permitted. If a given action could harm a species that might be endangered, do not allow it. The precautionary principle may appeal to common-sense notions of safety, but its application will not produce a safer, cleaner world. Quite the opposite — the incorporation of the precautionary principle in environmental, health, and safety regulation is itself a threat to environmental protection and optimal safeguards for public health.
At its core, the precautionary principle embodies the idea that it is better to avoid harmful activities than to try and rectify any resulting after the fact. In this way, it appeals to the common-sense idea that "it is better to be safe than sorry." Simple safety measures, such as wearing a seatbelt or motorcycle helmet, can greatly reduce the risk of substantial harm at relatively modest cost. Yet safety at any cost is rarely, if ever, a sensible policy. As advocated by environmental activists, the precautionary principle calls for a presumption that government action is required to address every potential risk. Drastic changes in regulatory policy are therefore required. In the words of its proponents, "new principles for conducting human affairs are necessary" as it is time to "adopt a precautionary approach to all human endeavors."
A conventional formulation of the precautionary principle is outlined in the "Wingspread Consensus Statement," a document drafted by several dozen environmental activists in January 1998: "When an activity raises threats of harm to human health or environment, precautionary measures should be taken even if some cause and effect relationships are not fully established scientifically." As applied in the environmental context, this means "decision makers should act in advance of scientific certainty to protect the environment (and with it, the well-being of future generations) from incurring harm." In this sense, the precautionary principle establishes a default rule for regulating new innovations, irrespective of the relative risk that they actually pose to human health or the environment. At its extreme, the principle calls for the elimination of substances and activities that are not "proven safe."
By emphasizing the need to act in the face of scientific uncertainty, before there is clear evidence of scientific harm, the precautionary principle lowers the threshold for what is considered reliable evidence of a potential effect. "Better safe than sorry" can be used to call for regulatory measures when there is little, if any evidence of an actual health or environmental impact. After all, it is impossible to prove a negative, so one can never prove that a given substance or activity entails zero environmental risk. There is no evidence that even a single individual has ever suffered a negative reaction from eating genetically engineered food — not a single documented case. The same cannot be said for "conventional" food. Yet proponents of the precautionary principle call for moratoria on the development and marketing of such products because such risks are "possible" and have yet to be unproven.
Most proponents of the precautionary principle seek to regulate or eliminate specific technologies or chemical byproducts. Groups such as Friends of the Earth and Environmental Defense appeal to the precautionary principle in calling for greater limits, if not complete moratoria, on the development and marketing of genetically modified crops. The "Safe Trade" campaign seeks to incorporate precautionary regulation into global trade rules under the World Trade Organization. A group called Health Care without Harm seeks to ban the use of phthalate plasticizers in medical supplies for fear they might have, as-yet-unproven, negative health impacts. The precautionary principle is also a driving force behind arguments for adoption of the Kyoto Protocol on climate change.
Perhaps the most ambitious manifestation of the precautionary principle in environmental policy is the effort to eliminate the use of chlorine compounds, from the manufacture of pesticides and solvents, to pharmaceuticals and water purification. Several chlorine compounds, including PCBs, dioxins, and chlorofluorocarbons (CFCs), have been linked to public health or environmental problems. CFCs, for example, are largely responsible for depletion of stratospheric ozone. On this basis, Greenpeace and others call for applying the precautionary principle to all chlorine-based compounds, sunsetting existing uses and prohibiting new ones. No uses of chlorine are considered safe. Not the purification of water, nor the production of life-saving pharmaceuticals. Scientific researchers know this position is absurd. "It isn't taken seriously from a scientific point of view," Dr. Mario Molina told Science magazine. Yet it is the logical application of the precautionary principle as formulated by environmental activists.
The precautionary principle may seem extreme, but it has become a mainstay of environmental law. Precautionary statements can be found in numerous environmental treaties and precautionary thinking has affected the implementation of U.S. environmental laws, including pesticide regulation and the Endangered Species Act. In 1996, the President's Council on Sustainable Development (PCSD) embraced the precautionary principle, as did Christie Todd Whitman before she became Administrator of the Environmental Protection Agency.
On the other hand, regulatory czar John Graham, head of the Office of Information and Regulatory Affairs, has suggested that the precautionary principle is not official Bush-administration policy. While it is always possible to identify instances in which precautionary regulation could have averted serious harms, Graham noted in a recent speech that there are many instances in which postulated risks never materialized. In these cases, precautionary measures would have wasted scarce resources and done nothing to enhance public health. "Precaution is a necessary and useful concept but it is also subjective and susceptible to abuse," Graham explained, and therefore cannot be the focal point of regulatory policy.
In theory, the precautionary principle enhances protection of public health and environmental concerns by reducing the threats posed by new technologies and development. In practice, this is not the case. By focusing on one set of risks — those posed by the introduction of new technologies with somewhat uncertain effects — the precautionary principle turns a blind eye to the harms that occur, or are made worse, due to the lack of technological development. Reflexive efforts to regulate one risk can create other, often more dangerous risks. New technologies can be risky things, but a Luddite world is hardly safer.
"The truly fatal flaw of the precautionary principle, ignored by almost all the commentators, is the unsupported presumption that an action aimed at public health protection cannot possibly have negative effects on public health," observes professor Frank Cross of the University of Texas. If the true aim is a safer world, and not merely the retardation of technological progress, the risks of substances and activities must be weighed against the risks that they ameliorate or prevent. The risks of change must be weighed against the risk of stagnation. In every case, "[t]he empirical question is whether the health [and environmental] gains from the regulation of the substances involved are greater or lesser than the health [and environmental] costs of the regulation," noted the late Aaron Wildavsky in Searching for Safety. Limitations on chemicals can reduce the availability of lifesaving medicines. Controls on pesticides may leave more exposed to insect-borne disease. Limits on biotechnology could stall increases in agricultural productivity and leave millions of Africans unfed. And so on.
"The precautionary principle rests upon an illusion that actions have no consequences beyond their intended ends," explains Cross. In reality, even the most well-intentioned precautionary measures can have terrible results. The precautionary principle's threat to technological progress is itself a threat to public health and environmental protection. The world would be safer without it.
— Jonathan H. Adler is an assistant professor at Case Western Reserve University School of Law and an NRO contributing editor. This essay is adapted from his chapter in the new book, Global Warming and Other Eco-Myths, edited by Ronald Bailey.