Introduction

According to Elizabeth Fisher, Judith Jones and René von Schomberg:

Significantly, the principle can be viewed as representing ‘a departure from the previous state of affairs where political actors could use or abuse a persistent dissent among scientists as a reason (or excuse) for not taking action at all’.

In line with this principle, and possibly as its most celebrated articulation, Principle 15 of the Rio Declaration in 1992 enjoins states to take measures to prevent serious and irreversible damage to the environment even if there is a ‘lack of full scientific certainty’. In other words, even if there is some doubt about whether, say, carbon emissions cause serious and irreversible climate change, at the very least, lack of clinching evidence should not stand in the way of preventive measures and, at strongest, preventive measures should be taken. Similarly, in a health care context, it might be urged that, even if there is some doubt about whether smoking tobacco causes lung cancer and heart disease, this should not bar the taking of preventive measures. As the Appellate Body at the WTO remarked in the Hormones dispute, ‘responsible, representative governments commonly act from perspectives of prudence and precaution where risks of irreversible, e.g., life-terminating, damage to human health are concerned’. Although the Rio Declaration qualifies the protective obligation by limiting it to the capabilities of particular states, and even though the nature of the measures to be taken is unspecified, the precautionary principle has attracted a huge amount of criticism.