Much has been said about the semantic content of various environmental as well as other principles, but there is less clarity about their legal nature. This chapter will propose a general concept of principles which can be applied to all levels of the law, national, regional, as well as international. The concept views principles as a transmission belt between societal common sense and the law. If seen in this light, principles can help to accelerate the making of environmental law, so much needed at a time of asynchronie between the speed of global environmental change and the slowness of institutional response. I will begin with a short overview of the rhetoric of environmental ‘principles’, and develop a definition of ‘principle’ suggesting that there are different definitions for different legal contexts in which ‘principles’ appear.

Overview of environmental propositions called principles

In international law, three environmental propositions are widely cited as principles, namely the sovereign right of states over their natural resources, the procedural duty between states to cooperate in mitigating environmental risks and emergencies, and the substantive duty to prevent, reduce, and control imminent and serious environmental harm. These principles are recognised as rules of international customary law. They can also be regarded as ‘principles of international law’. The third – prevention of serious harm – may even qualify as a ‘principle of peremptory law’ (ius cogens).