This book concentrates on environmental economics with emphasis on policy measures at national and global level to achieve sustainable development. This third edition of the book is an enlarged version of the earlier editions and provides a clear easy-to-understand overview of the subject that is gaining importance among present day teachers, students and researchers in economics. The objective of the third edition is to update the second edition and make the book more informative. Changes have been made in almost all chapters in this revised edition, besides the newly added chapters. Almost all the chapters of the earlier editions have been rewritten, incorporating latest ideas and information from academic and policy documents in appropriate contexts. Extensive enlargement of existing chapters complement the new chapters, particularly those on policy instruments, and practice of environmental policy at national and international level and sustainable development. The concept and theories in the various chapters are supported with suitable case studies. Every chapter contains exercises to encourage the students to take up short projects or to write articles on environment related issues.