Environmental Studies is a vast and rapidly growing subject with increasing relevance for sustainable development. It is the systematic study of environment, with our proper place and role in it. Realizing the importance of imparting environmental education, the Supreme Court directed that a basic course on environment be introduced as a compulsory subject at all levels of education. Textbook of Environmental Studies deals with the various facets and dimensions of environment in an integrated, multidisciplinary and holistic manner. It provides an up-to-date, introductory view of essential topics in environmental studies to help students understand and retain the general principles. It is written with the understanding that even students without prior background in science should be able to use it, and so it has not been laid heavy with technical jargon. At the same time, it has enough depth to make it suitable as a textbook for students of different courses including humanities, commerce, science and engineering.