According to estimates, more than 7 billion people live on our planet. Each day, some 200,000 new babies add to this figure, which works out to roughly 140 additional people per minute. Over an entire year, about 80 million humans are born—a number comparable to the combined populations of California, Texas and New York. Not every region of the world is witnessing this staggering rate of growth, however. In developed areas like Western Europe and Japan, the population has essentially stabilized, while in less developed countries fertility tends to be much higher. Even with this variation, experts predict that more than 9 billion people will jostle for space on Earth by 2050.
It wasn’t always this way. Population growth of such proportions is a relatively new phenomenon: Between 1900 and 2000, the number of people in the world quadrupled, and between 1700 and 2000 it climbed by a factor of 10. Indeed, for tens of thousands of years, the human populace expanded at tiny fractions of today’s 1.1-percent yearly rate. When our ancestors first turned to agriculture around 8000 B.C., an estimated 5 million people were scattered across the planet. By 1 A.D. that figure had climbed to roughly 200 million, increasing by only 0.05 percent each year. The population would continue to grow slowly but surely, although catastrophic scourges such as the Black Death—blamed for killing up to half of all Europeans during the 14th century—imposed periodic setbacks. When the Industrial Revolution took off in the mid-1700s, life expectancy trended upward as child mortality plummeted, resulting in a population explosion that brought the total number of humans to 1 billion by 1800.