At a level accessible to the educated lay reader, this book describes what changes human activities have produced in the global environment from 300 years ago to the present day. It offers a comprehensive and authoritative inventory of human impact in its varied forms - on the land, oceans, atmosphere, and climate - ranging from long-standing alterations to new and surprising ones that have emerged in recent years, from environmental disasters to false alarms to success stories of environmental management. This balanced, nonpolemical survey will interest all those concerned about the environment and the likely fate of the planet.