This bulletin examines the narrowing margin between global food production and population growth. Between 1950 and 1971, world grain production nearly doubled and per capita production increased 31 percent. During the 1970s, gains in output barely kept pace with population growth, consumption per person declined in sub-Saharan Africa and parts of Asia, food prices were volatile, and over 100 food-deficit countries came to depend on the exportable surplus of North America, now the only major grain-exporting region. The world fish catch leveled off in the early 1970s and beef production, still dependent mainly on grassland grazing, leveled in the mid 1970s. With little new land left to plow, satisfying increased food demand now depends on sharp increases in yields on existing cropland. Worldwide, this effort is hampered by loss of topsoil and irrigation land, conversion of cropland to nonfarm uses, rising energy costs, inefficient agrarian structures (particularly in the Soviet Union), the falling yield responses to chemical fertilizers in agriculturally advanced countries, and the emerging competition between food and agriculturally based energy crops. Green Revolution successes in some developing countries demonstrate that, given the right inputs, Third World farmers can increase crop yields dramatically. Most important in meeting food needs on a finite planet is slowing population growth. (Author)