Synopsis Man as an important biotic component of the ecosystem depends on his environment for sustenance.  Various human activities resulted into many changes in the quality of air, water and land.  These changes in turn have produced detrimental effects on the whole ecosystem.  This book contains articles that discuss the causes and effects of such environmental changes.  Human concern about the environment at the international level got a concrete shape in 1972 at the United Nations Conference at Stockholm.  In the same year United Nations Environment Programme came into being with the mission to "provide leadership and encourage partnership in caring for the environment by inspiring, informing and enabling nations and people to improve their quality of life without compromising that the future generations."  Since then in the following three and a half decades efforts have been taken on different levels to conserve nature and natural resources.  This book also provides information of various strategies needed for proper environmental management aiming towards sustainable development.