What about overpopulation?
It’s an inevitable question. Conventional wisdom says that the demands of an ever-growing number of humans will soon push our planet’s resources to the limit. Surely any discussion of “the future of population” would have to focus there. But two pieces of information steered me—and this issue—in a different direction.
One is the history of failed projections about the consequences of population growth. The most notorious warning came from English economist Thomas Malthus, who in 1798 wrote: “Population, when unchecked, increased in a geometrical ratio, and subsistence for man in an arithmetical ratio.” In other words, mouths multiply more quickly than our ability to feed them—yet we are still feeding them. In his 1968 best seller, The Population Bomb, biologist Paul Ehrlich more specifically declared, “In the 1970s and 1980s, hundreds of millions of people will starve to death in spite of any crash programs embarked upon now.” Famines on that scale never arrived.
Second and more important is why Malthus and Ehrlich were so wrong. Resources are not fixed things. Better farming can drastically increase the food supply. New energy sources enable much higher standards of living. And then behavior changes in response: More access to resources tends to make people have fewer children, not more. As a result the world’s population will probably hit its peak around 2100, followed by a historic leveling off and likely downturn.
Those changes will have their own disruptive effects. We will see an overall aging of the world that could slow economic growth and fray the social nets that support the elderly. We will see more of the afflictions of old age and greater efforts to eliminate aging entirely. Today’s inequalities and environmental challenges will not go away, and may yet reach crisis levels.
But mass starvation is even less likely today than it was in Ehrlich’s heyday. Human ingenuity and behavior, not gross numbers, are the real secret to understanding where our species is headed.