The Ehrlichs, best known for The Population Bomb (1970) and The Population Explosion (1990), say here that the present book was written "to fill in the rest of the picture, to explain how overconsumption and the use of faulty technologies contribute to the deterioration of the environment.''
But overpopulation remains their major bugaboo as they survey the global problems associated with energy consumption, global warming, ozone depletion, unsustainable agriculture, and various forms of air, land, and water pollution. They "summarize'' the blame for all of this with the equation "I=PAT'' (impact = population x affluence [as a measure of consumption] x technology), pointing out that as P increases so does T; but with or without that formula they offer no significant new insights on these often discussed problems. And, title and subtitle notwithstanding, they emphasize the problems more than the solutions and never get down to nitty-gritty "strategies'' for implementation. Aside from limiting population growth, their most frequent suggestion, whatever the problem, is to discourage environmentally damaging habits by imposing consumption fees and taxes and marketable "depletion quotas.''
So: what we have here, besides the venerable Ehrlich name, is an overview from their perspective, for their followers.