HOW MANY PEOPLE CAN THE EARTH FEED

Many attempts have been made to estimate the carrying capacity of the Earth, but the inherent complexities of nutritional, environmental, agricultural, and economic variables make all ultimate, single-value results questionable. In contrast, a conservative assessment of all important factors limited to a period of two or three generations can provide some revealing perspectives. By far the most important outcome of such an exercise is the identification of substantial inefficiencies throughout the food production and consumption chain. A combination of improved agronomic practices (above all, higher efficiencies of fertilizer and water use), lowered postharvest waste, and healthier eating (mainly reduction of fat intake) could produce adequate nutrition for an additional 3. billion people without any increase in existing inputs. Furthermore, realistic mobilization of new productive inputs could secure enough food for yet another 2 billion people. Consequently, there appear to be no insurmountable obstacles lo feeding the global population of about 10 billion people expected by the middle of the twenty-first century.