Social Decision-Making under Scientific Controversy, Expertise, and the Precautionary Principle

Integrating scientific inputs into the regulatory process is generally attributed to experts. But, environmental issues are often characterised by an all-pervasive uncertainty and scientific and social controversies which make the experts' task difficult. This paper presents the concept of social decision-making under scientific controversy and comes to an examination of the implicit but decisive roles expected from expertise in those contexts. It also gives some examples of misunderstandings about the very nature of scientific statements. Since a new principle, the Precautionary Principle, is said to bring appropriate responses to uncertainty, we examine the change in the course of relationship between science and decision-making it may have and we test its operational capability to solve decision problems on a scientific basis. Our conclusion is that in controversial contexts, the Principle has no definite content and is not able to frame a scientifically determined hierarchy of options. So, to have it reasonably translated to deal with practical matters, some effort is expected from scientific communities : they should organise a collective validation of their expertise, distinct from the organisation of expertise by public administrations. This expertise by scientists should consider with due attention the process of formulation of assumptions and building conjectural possibilities, so as to define the boundaries of relevance for action and to establish some gradual scale in the qualification of scientific products which may authorise gradual precautionary measures to be taken.