This book presents a comprehensive account of the concepts of Environmental Studies compulsory course for all undergraduate streams. During the past three decades, there has been an explosion of books on environmental problems. However, this book is different in a sense that it approaches the various environmental issues with an enigma in mind. Written in question-answer format, it is easy for the student to directly address the subject area and understand it to the point. The main objective of the book is to improve the knowledge and concern towards preservation of our environment. This book will be ideal as a text for students, and will also be of interest to researchers and consultants in the environmental sciences. It will be equally beneficial to the candidates preparing for various competitive examinations. A large number of latest updates, examples and case studies are included. Multiple-choice questions at the end of each chapter will help the students to prepare for the examinations. A detailed Glossary has also been given at the end of the book.