Estimates of whether food supplies will be adequate over the next 30 years range from warnings to qualified reassurances. Food requirements, what is needed to avoid hunger, are not the same as economic demand. Food security requires more than simply meeting requirements on a world scale; food must reach every country and all sections of the community, with adequate provision for a bad harvest year. Projections into the future start from a position that is already in deficit in the 1990s: 800 million people undernourished, massive food imports by developing countries with an accompanying burden of debt, and widespread occurrence of land-degrading management practices. In developing countries between now and 2025, population change alone will require an increase in food supplies of 55%, and dietary changes will add to this demand.

Future growth in food production can only come from more land or higher yields. But the land still available for cultivation has been greatly overestimated; present cultivation is more extensive than shown in official statistics, and most remaining land is already under necessary alternative uses. Future growth in crop yields will be slower and harder to achieve than in the past; some regions are experiencing a yield ceiling in response to inputs. Even to prevent the situation from worsening, with continued land degradation and declining per capita food supplies, will require a greatly increased commitment to agriculture by governments of developing countries. But, unless accompanied by efforts to reduce the rate of population growth, even such an increased commitment may not be enough.