At the root of much of the concern about the environment is the worry that global population growth could eventually outstrip the capacity of the world to feed itself. Concern over excessive population growth, of course, dates back to the fears expressed in the early nineteenth century by the British economist Thomas Malthus, who worried that population growth would increase more rapidly than food supply. It peaked in the decades immediately following World War II, when a rise in world birthrates and a decline in infant mortality combined to fuel a dramatic increase in population in much of the Third World. The concern was set aside for a period after the 1970s, when the Green Revolution improved crop yields and statistical evidence appeared to suggest that the rate of population growth was declining in many countries of Asia and Latin America. Yet some experts question whether increases in food production through technological innovation (in recent years, the Green Revolution has been supplemented by a “Blue Revolution” to increase food yields from the world’s oceans, seas, and rivers) can keep up indefinitely with world population growth, which continues today, though at a slightly reduced rate from earlier levels. From a total of 2.5 billion people in 1950, world population rose to 5.7 billion in 1995 and is predicted to reach ten billion in the middle of this century. Today, many eyes are focused on India, where the population recently surpassed one billion, and on China, where family planning programs have lost effectiveness in recent years and where precious rice lands have been turned to industrial or commercial use.