Abstract
The development of international environmental law is typically divided into three periods. The first demonstrates little genuine environmental awareness but rather views environmental benefits as incidental to largely economic concerns such as the exploitation of living natural resources. The second demonstrates a significant rise in the number of treaties directed to pollution abatement and to species and habitat conservation. Here an overt environmental focus is evident, yet the approach is still largely reactive and piecemeal. The final phase, which characterizes current international environmental law, demonstrates a precautionary approach to environmental problems of global magnitude such as biodiversity conservation and climate change. Concern transcends individual States, with certain global problems now considered the common concern of humankind. This chapter defines international environmental law, its key sources and actors, and difficulties of enforcement, before embarking on a sectoral examination of the extensive treaty law applicable in this field.