Realizing the Precautionary Principle in Due Diligence

The precautionary principle is a legal principle that has found considerable support in international environmental law. Its emergence, however, has not been without problems and controversies: how do we define its normative content and trigger elements, and how do we ensure concrete implementation. The 2011 Seabed Mining Advisory Opinion used states’ due diligence obligations to prevent harm to realize the precautionary principle. Focusing on this case, this article examines how the precautionary principle can be applied using the concept of due diligence. First, this article explores the precautionary concept using examples from a selection of regional and multilateral environmental instruments, analyzing its origin and different expressions and identifying the problems in its application. Second, the article analyzes the Pulp Mills case and the Seabed Mining Advisory Opinion to substantiate the role of the obligation to take precautionary measures in the legal framework of due diligence. Third, by reference to the International Law Commission’s Draft articles on Prevention of Transboundary Harm from Hazardous Activities and the International Law Association’s study report on the Legal Principles relating to Climate Change, along with a number of international cases, the article further illustrates the distinction between due diligence, prevention and precaution and argues that they are actually interrelated