The second edition of this leading work on international environmental law investigates the ways in which international environmental law is developed, implemented, and enforced. Rather than focusing on only some aspects of the international environmental process, it examines the process as a whole, from beginning to end, synthesizing recent research on international environmental negotiations, treaty design, social norms, policy implementation, and effectiveness. The book sketches the context of contemporary international environmental law, including its history, the causes of global environmental problems, and proposed policy solutions. The book also reviews the nature of international environmental norms, offering detailed accounts of both treaty-based norms and non-treaty norms. In addition, the book explores the growing complexity of international environmental law, discussing the changing roles of states and non-state actors in its development. It further examines how and why states implement and comply with international environmental law, and how international environmental norms can be enforced. The book is a sophisticated yet highly readable introduction to how international environmental law works (and sometimes doesn't work), for both specialists and the general reader.