The poet Philip Larkin famously said that sexual intercourse began in 1963. He could have said something similar about the environment and the 1970s. Although it has always been with us, only in that decade did the environment truly emerge as an important issue, and international environmental law (IEL) as a specialised subject of international law. This chapter is headed ‘International environmental law’ since much of domestic environmental law is not enacted merely to implement treaties, and indeed may be more advanced than IEL, which is almost entirely derived from treaties. The subject matter can be controversial and an area where NGOs, have been especially energetic. But, because of the sometimes widely differing views of states on what should be done to protect the environment, the degree to which NGOs influence policy-making at the international level can be exaggerated.

Environmental protection and the conservation of natural resources necessarily compete with commercial interests, and a commercial element is almost invariably present in any environmental dispute.