Robert L. Heilbroner

Life on this planet is a fragile affair, a kind of miraculous microbial activity that flourishes on the thin film of air and water and decomposed rock which separates the uninhabitable core of the earth from the void of space. Over most of mankind's history, the existence of that environment has always been taken for granted, and human efforts have been devoted to "taming" it-that is, to altering that vital film in various ways to assure our easier survival. Now, with stunning suddenness we have come to the realization that the environment is not to be taken for granted after all- indeed that it may be on the verge of an irremediable deterioration. For if the calculations of a group of social and physical scientists are correct, it will take only another 50 years of population growth and economic expansion at present rates to cause a collapse of our life-supporting ambient, bringing mass famine in some areas, industrial breakdown in others, a drastic shortening of lifespans nearly everywhere.