There's always room for one more.
In 1798, English clergyman Thomas Malthus published a slim but provocative volume titled An Essay on the Principle of Population. The book went viral (by 18th-century standards) for its stunning conclusion that "the power of population is indefinitely greater than the power in the earth to produce subsistence for man." If people kept procreating, Malthus argued, we'd run out of planet. Two centuries later, scientists are still grappling with that possibility.
For most of history, our numbers have been negligible. If Odysseus really did sail the wine-dark sea in the 12th century B.C., he was one of only around 50 million people alive at the time. As Muhammad composed the Quran some 1,800 years later, the population was roughly 200 million. But the Industrial Revolution pushed that crawl into a sustained sprint. Our numbers doubled in just 150 years, and Malthus’ world was making room for its 1 billionth member by 1804. How would they eat? What would they drink? Where would they live?
Malthus' answer was that they wouldn't; they'd die of hunger and disease. But he was clearly wrong. So the next Malthusian took up his anxious mantle, and the next. In his 1968 book The Population Bomb, biologist Paul Ehrlich predicted that by 1980, 4.4 billion humans would start to starve en masse. Yet we continued to skirt catastrophe.
There are now nearly 7.6 billion earthlings, a number inconceivable to Malthus, and maybe even Ehrlich. By the 2050s, there will be 10 billion. How will we eat? What will we drink? Where will we live? Read more >>