This book assesses the present state of international law concerning the protection of the world's natural environment. It does not seek to examine in detail all aspects of contemporary environmental problems, nor is it a work of policy analysis, rather it explores the basic principles, structure, and effectiveness of the international legal system as it relates to these issues. What emerges is intended to provide the reader with a clearer and more coherent picture of the remarkable developments in international law which contemporary concern for the state of the global environment has brought about. This is the most comprehensive major treatment of the subject in English, by two authors with many years' experience of teaching and writing in this field. This book is intended for undergraduate courses in environmental law, international law. Practitioners of environmental law, Government lawyers, international organizations.