Part III Conceptual Pillars, Ch.16 Harm Prevention

This chapter addresses how international environmental law originates from and revolves around the harm prevention rule. It focuses on three points of contention, each related to the role of due diligence in harm prevention, and each highlighted by recent judicial engagements with the harm prevention rule. First, it is generally accepted that a state's obligation to prevent environmental harm is not absolute, but requires due diligence in the face of risk of significant harm. However, it is unclear whether a failure to act diligently to avert harm on its own—absent actual harm—can amount to a breach of the harm prevention rule. Second, the relationship between the procedural and substantive dimensions of the harm prevention rule remains ambiguous. Third, there is some uncertainty as to where the line runs between the harm prevention obligation and the precautionary principle, given the focus of both notions on risk. These inter-related conceptual questions affect the harm prevention rule's function as a reference point for international environmental law.