Environmental science is an interdisciplinary field. Because environmental disharmonies occur as a result of the interaction between humans and the natural world, we must include both when seeking solutions to environmental problems. Environmental Studies is a compulsory paper for undergraduate students in almost all disciplines in India. The purpose of teaching this course is to sensitize students towards environmental issues. The book introduces students to the fundamental principles of environmental science, its introduction, evolution and history and how environment is made from various components ecology and allied topics including ecosystems, biodiversity, population, policy, law, pollution control, economics, natural resource management and sustainable development. This book provides detailed discussion on fundamental concepts and issues – including global warming, acid rain, ozone layer depletion, nuclear accidents etc. – related to the environment. Focusing on the immediate need for public awareness, the book discusses various natural resources such as water, land, forests, food and mineral, and the problems associated with them. Using examples, it introduces and explains different types of ecosystems, biogeochemical cycles and laws of thermodynamics. This book is a comprehensive account of the fundamentals of environmental science and shall be a useful resource for the students.