The precautionary principle governs the use of foresight in decision-making in situations characterized by uncertainty and ignorance and where both regulatory action and inaction carry potentially large costs. When an activity raises threats of harm, precautionary measures should be taken even if some cause and effect relationships are not fully established scientifically. The key element of the precautionary principle is that it incites anticipatory action in the absence of scientific certainty. The precautionary principle shifts the burden of proof, insisting that those responsible for an activity must vouch for its harmlessness and be held responsible if damage occurs. The issues of scientific uncertainty, economics, environmental and public health protection which are embedded in the principle make this extremely complex.
The process of applying the precautionary principle is open, informed and democratic and must include potentially affected parties. It also involves an examination of the full range of alternatives, including no action.
The precautionary principle requires that decision-makers take into account not just the likelihood of a hypothesis being wrong (the degree of uncertainty) but also the nature and scale of the consequences if it is wrong. Some risks are unacceptable not because they have a high probability of occurring but because the consequences if they do occur are so severe. In view of this, the possibility of irreversible or persistent effects (as with persistent organic pollutants) calls for a different approach than in situations where transient effects are involved.
The precautionary principle is a concept on which environmental legislation and international agreements increasingly lie. It has become intrinsic to international environmental policy, especially with the adoption, in 1992, of the Rio Declaration at UNCED. Principle 15 of that Declaration provides that: "In order to protect the environment, the precautionary approach shall be widely applied by States according to their capabilities. Where there are threats of serious or irreversible damage, lack of full scientific certainty shall not be used as a reason for postponing cost-effective measures to prevent environmental degradation".
The principle is enshrined in the European Union treaty. The most significant support for the principle in Europe has come from the European Commission's Communication on the Precautionary Principle, the European Parliament's resolution on the Communication and the Council of Ministers' Nice resolution on the precautionary principle, all issued in 2000.
In 1998, a gathering of 32 scientists, philosophers, lawyers and environmental activists, reached agreement on the necessity of the Precautionary Principle and called for government, corporations, communities and scientists to implement the "precautionary principle" in making decisions in the following statement:
The Convention on the Protection and Use of Transboundary Watercourses and International Lakes describes the application of the precautionary principle as follows: The precautionary principle, by virtue of which action to avoid the potential transboundary impact of the release of hazardous substances shall not be postponed on the ground that scientific research has not fully proved a causal link between those substances, on the one hand, and the potential transboundary impact, on the other hand.
Article 5(a) of the Draft Protocol on Water and Health (1999) to the Convention on the Protection and Use of Transboundary Watercourses and International Lakes (1992), requires parties to be guided by: The precautionary principle, by virtue of which action to prevent, control or reduce water-related disease shall not be postponed on the ground that scientific research has not fully proved a causal link between the factor at which such action is aimed, on the one hand, and the potential contribution of that factor to the prevalence of water-related disease and/or transboundary impacts, on the other hand.
The Cartagena Protocol on Biosafety to the Convention on Biological Diversity affirms several times the precautionary approach and the appropriateness of taking protective action where there is a "lack of scientific certainty due to insufficient relevant scientific information and knowledge regarding the extent of the potential adverse effects..."
The challenge facing the international community is how to attain truly precautionary environmental policies. This challenge is one of changing perceptions as much as of changing institutions or technical mechanisms. It is a challenge to the way of viewing the world as much as to views of the role of science, or the burden of proof. It also raises a question as to the role of legal and other regulatory instruments in implementing the precautionary principle. Where the relationship between international, national and local policies is concerned, there is a need for new approaches, in particular to enable public participation.
The idea of precaution underpins some U.S. policy, such as the requirement for environmental impact statements before major projects are launched using federal funds.
In the European study Late lessons from early warnings: the precautionary principle 1896-2000, which examines how the concept of precaution has been applied – or not – by policy-makers over the past century when addressing a broad range of hazards linked to public health and the environment in Europe and North America, the 12 "late lessons" are: (1) Acknowledge and respond to ignorance, as well as uncertainty and risk, in technology appraisal and public policy-making; (2) Provide adequate long-term environmental and health monitoring and research into early warnings; (3) Identify and work to reduce blind spots and gaps in scientific knowledge; (4) Identify and reduce interdisciplinary obstacles to learning; (5) Ensure that real world conditions are adequately accounted for in regulatory appraisal; (6) Systematically scrutinize the claimed justifications and benefits alongside the potential risks; (7) Evaluate a range of alternative options for meeting needs alongside the option under appraisal, and promote more robust, diverse and adaptable technologies so as to minimise the costs of surprises and maximize the benefits of innovation; (8) Ensure use of "lay" and local knowledge, as well as relevant specialist expertise in the appraisal; (9) Take full account of the assumptions and values of different social groups; (10) Maintain regulatory independence from interested parties while retaining an inclusive approach to information and opinion gathering; (11) Identify and reduce institutional obstacles to learning and action; (12) Avoid "paralysis by analysis" by acting to reduce potential harm when there are reasonable grounds for concern.
Most existing laws and regulations focus on cleaning up and controlling damage rather than preventing it. These policies do not sufficiently protect people and the natural world. Current policies such as risk assessment and cost-benefit analysis give the benefit of the doubt to new products and technologies, which may later prove harmful. And when damage occurs, victims and their advocates have the difficult task of proving that a product or activity was responsible.
I accept the legitimacy of the concept of precaution in the field of environment and health. A danger lies in having a general, open-ended precautionary principle without defining what it means, and in what circumstances it may be used. The challenge is to develop a methodology for applying the principle of precaution. A set of guidelines should be developed which could, include the following: a) the implementation of a precautionary measure must start with a scientific evaluation of the available information; b) the measures developed should be proportional, non-discriminatory, and consistent with measures already taken in similar circumstances; and c) the measures should be provisional, and should be kept under review until full scientific advice permits a definitive decision.