The precautionary principle in environmental science

Environmental scientists play a key role in society's responses to environm ental problems, and many of the studies they perform are intended ultimatel y to affect policy. The precautionary principle, proposed as a new guidelin e in environmental decision making, has four central components: taking pre ventive action in the face of uncertainty, shifting the burden of proof to the proponents of an activity; exploring a wide range of alternatives to po ssibly harmful actions; and increasing public participation in decision mak ing. In this paper we examine the implications of the precautionary princip le for environmental scientists, whose work often involves studying highly complex, poorly understood systems, while at the same time facing conflicti ng pressures from those who seek to balance economic growth and environment al protection. In this complicated and contested terrain, it is useful to e xamine the methodologies of science and to consider ways that, without comp romising integrity and objectivity, research can be more or less helpful to those who would act with precaution. We argue that a shift to more precaut ionary policies creates opportunities and challenges for scientists to thin k differently about the ways they conduct studies and communicate results. There is a complicated feedback relation between the discoveries of science and the setting of policy. While maintaining their objectivity and focus o n understanding the world, environmental scientists should be aware of the policy uses of their work and of their social responsibility to do science that protects human health and the environment. The precautionary principle highlights this tight, challenging linkage between science and policy.