Neo-Malthusian theory holds that population growth is exponential and that human population growth can easily outstrip its food resources if not held in check with artificial birth control measures. It differs from traditional Malthusian theory in the proposed birth control solution.
Sociologist Paul Erlich and economist Thomas Keynes both shaped the neo-Malthusian movement. Their ideas are based on the theories of Thomas Malthus, an 18th century minister who warned that exponential population growth not held in check by natural attrition like disease leads to famine as population outstrips food supply. The neo-Malthusians are enthusiastic proponents of birth control; their theory is that birth control prevents a population explosion, particularly among the poor, and thus avoids a new Dark Age because of the chaos and war brought by famine.
Neo-Malthusianism, like its originator, has been largely discredited. Advances in science led to more robust food plants that produce large crops even under poor growing conditions. The natural adoption of birth control in an increasingly literate world has lowered the birth rate as well. However, modern neo-Malthusians still argue that even if food is not the problem it appeared it might be, energy and other resources necessary to a modern society are still heavily stressed by a growing world population. Additionally, artesian wells in parts of the world with low rainfall may still lead to food crises in localized regions, creating famine and chaos where people had become accustomed to being well-fed.