In the 1973 movie Soylent Green, the world had turned (spoiler alert!) to cannibalism to feed its billions of unwashed masses by 2022. But nine years before that milestone, it looks as if the world’s population could actually be starting to decline.
The number of people on the planet has grown exponentially in the past half-century alone, from 2.5 billion in 1950 to an estimated 7 billion in 2012, according to the U.S. Census Bureau. The world’s 7 billionth person, born sometime last March, elicited concern that we would run out of food and resources for everyone. An ever updating Census Bureau population clock shows the numbers rising.
People have worried about this since at least the 18th century, when British political economist Thomas Malthus first theorized that unchecked population growth would ultimately lead to starvation. China, so concerned about the drain of overpopulation on its resources, instituted a one-child policy in 1979, imposing heavy fines on parents who go over the limit.
But it turns out the world’s population isn’t growing nearly as fast as it once did. In fact, experts say the rate of population growth will continue to slow and that the total population will eventually — likely within our lifetimes — fall.
This isn’t news for two of the world’s most populous countries, Japan and Russia, which as TIME reported in 2011 are both facing rapidly declining birthrates. In general, developed countries where more women have the means for financial independence and motherhood isn’t a given are facing much slower rates of population growth. Many Western European countries have birthrates below the population-replacement rate of 2.1 births per woman: Spain and Italy are tied at 1.4; Holland and Belgium, 1.8; and Germany is at 1.36.
The U.S. has seemingly been immune to the declining-birthrate trend. But in 2011, the Pew Research Center found that the birthrate in the U.S. reached its lowest point ever recorded: 63.2 children per 1,000 women of childbearing age.
In Slate, Jeff Wise reports that the babymaking slowdown is due to “demographic transition” — basically, the phenomenon whereby humans, long used to having large families to cope with the society-decimating consequences of famine, war and disease, begin to rein in childbirth as these threats dissipate. Warren Sanderson, a professor of economics at Stony Brook University, explained it to Wise as “a shift between two very different long-run states: from high death rates and high birthrates to low death rates and low birthrates.”
Looks as if we may not have to eat one another after all.