Of all the doomsday predictions about our planetary future from the 1960s and 1970s, perhaps none was so comically off the mark as the widespread fear about overpopulation. The dystopian portrayals of out-of-control population growth outstripping the planet’s ability to sustain human life made for good sci-fi movies; “Soylent Green” comes to mind. But the exponential expansion of the planet’s human population never materialized.
In fairness, making predictions is always a hazardous undertaking. And many of the other gloomy projections from that time were more prescient, particularly with regard to environmental degradation. But when it comes to human demographics, the reality has proven to be just as alarming, if for the opposite reason: In every region of the world except Africa, population levels have begun to level off due to declining birthrates, with some countries—like China—experiencing population decline and others bracing for it.
And because much of the population increases of recent years can be attributed to increased life expectancy due to advances in health and nutrition, instead of an overcrowded planet, what lies ahead for most of the world is a graying planet, as the demographic balance begins to tilt toward aging populations.