Traces the development of an international discourse of crisis through the influence of such thinkers as William Vogt, Fairfield Osborn and Georg Borgstrom, labelled 'neo-Malthusians' for their emphasis on an impending clash between population growth and resource limits, after the manner of the nineteenth century father of scarcity economics. He analyses the role of science and technology in securing food supply, the transmutation of older ideas about preserving nature into a new conservation ideology based on sustainable use.