The Earth with all its inhabitants, including man, has had a long history as a slowly evolving complex system which normally exists in a state of stable dynamic equilibrium. Explosive growth in the human population, in the per capita use of nonrenewable resources, and in the degree of human disruption of established ecosystems represents a major departure from this state of equilibrium and an ecological crisis of global dimensions. This growth, and the rapid changes that arise from it, have had such a pervasive influence on the collective experience of man that they have come to be regarded as the normal course of events on a stable Earth. This has fostered the notion that growth will always be essential for further improvements in the quality of human life. Rapid growth began only two hundred years ago when the developing technology of the industrial revolution made possible the large-scale exploitation of the Earth' fossil-fuel resources and the creation of positive feedback growth in technology and growth in fossil-fuel production. Annual growth rates in world production of fossil fuels and ores of representative industrial metals, when compared with the nature and finite magnitude of the Earth's resources, lead to the inescapable conclusionmore » that the present episode of exponential growth can only be a transitory epoch of a few centuries duration within the totality of human history. Solar radiation offers the prospect of large supplies of energy with minimal environmental impact. However, constraints on growth due to the finite nature of food and mineral resources and the effects of environmental degradation can only be loosened in this way, not removed. Mankind faces an inevitable transition from a brief interlude of exponential growth to a stable condition characterized by rates of growth so slow as to be regarded essentially as a state of no growth. Failure to respond rationally and promptly to this situation could be disastrous.« less