This revised and enlarged edition is prepared for all Indian Technical and NonTechnical Universities. Ecosystem, Social Issues and Environment; Marine, Thermal, Nuclear Pollutions, Natural Resources, Human Population and Environment. Ethics and Moral Values are added in this. All new topics presented in this edition are very understandable manner keeping in view the mental level of the students so that students may acquire the complete knowledge of the subject. Text material of this revised edition is more justifiable, case studies and examples are given at appropiate places. The language is simple and easy to understand.