This second edition of Richard Turco's successful book, Earth Under Siege, provides a basic understanding of how our physical environment functions and how human activities affect it. Intended to educate the lay person-especially the policy makers, business administrators, and political leaders of the future-about some of the most pressing problems facing our modern world, this important book effectively describes the realities of environmental pollution and global change. It provides a comprehensive description of the natural environment and builds a foundation on which the science and policy of current environmental issues can be understood, including key local, regional, and global issues and their implications for society and human life.