In this book the fundamental concepts of environmental studies have been introduced and analysed in a simple manner strictly as per the module syllabus designed by the U.G.C. for undergradute courses in science, humanities, engineering, medicine, pharmacy, commerce, management and law. Besides the undergraduate students of all disciplines the book will also be useful for those appearing in various competitive exams since environmental issues now find a focus in most of such examinations. The contents of the book will be of interest to all educationists, planners and policy makers.