"Human activities have assumed the biosphere's own orders of magnitude." To show us how to cope with this unprecedented situation, the former editor and publisher of Scientific American begins with an authoritative and enlightening synthesis of the earth and life sciences. There follows an extended discussion of economic (and to a considerable extent political) development. Piel argues that the environment can only be saved by bringing the industrial revolution to the four-fifths of the world that has missed much of it, and by acting on the principle that "the hazards to the environment laid by industrial technology . . . are subject to cure by technology." Then the world will be able to stabilize its population at twice its present size by the end of the 21st century. All this may require a "moral revolution" in the rich part of the world with a new emphasis on equity rather than growth. Needless to say there is a great deal to argue about with regard to both the past and the future in this remarkably wide-ranging book.