View a photo essay of The Grayest Generation.
"The World Faces a Population Bomb."
Yes, but of old people. Not so long ago, we were warned that rising global population would inevitably bring world famine. As Paul Ehrlich wrote apocalyptically in his 1968 worldwide bestseller, The Population Bomb, "In the 1970s and 1980s hundreds of millions of people will starve to death in spite of any crash programs embarked upon now. At this late date, nothing can prevent a substantial increase in the world death rate." Obviously, Ehrlich's predicted holocaust, which assumed that the 1960s global baby boom would continue until the world faced mass famine, didn't happen. Instead, the global growth rate dropped from 2 percent in the mid-1960s to roughly half that today, with many countries no longer producing enough babies to avoid falling populations. Having too many people on the planet is no longer demographers' chief worry; now, having too few is.
It's true that the world's population overall will increase by roughly one-third over the next 40 years, from 6.9 to 9.1 billion, according to the U.N. Population Division. But this will be a very different kind of population growth than ever before -- driven not by birth rates, which have plummeted around the world, but primarily by an increase in the number of elderly people. Indeed, the global population of children under 5 is expected to fall by 49 million as of midcentury, while the number of people over 60 will grow by 1.2 billion. How did the world grow so gray, so quickly?
One reason is that more people are living to advanced old age. But just as significant is the enormous bulge of people born in the first few decades after World War II. Both the United States and Western Europe saw particularly dramatic increases in birth rates during the late 1940s and 1950s, as returning veterans made up for lost time. In the 1960s and 1970s, much of the developing world also experienced a baby boom, but for a different reason: striking declines in infant and child mortality. As these global baby boomers age, they will create a population explosion of seniors. Today in the West, we are seeing a sharp uptick in people turning 60; in another 20 years, we'll see an explosion in the numbers turning 80. Most of the rest of the world will follow the same course in the next few decades.
Photos of a world going gray.
Eventually, the last echoes of the global baby boomers will fade away. Then, because of the continuing fall in birth rates, humans will face the very real prospect that our numbers will fall as fast -- if not faster -- than the rate at which they once grew. Russia's population is already 7 million below what it was in 1991. As for Japan, one expert has calculated that the very last Japanese baby will be born in the year 2959, assuming the country's low fertility rate of 1.25 children per woman continues unchanged. Young Austrian women now tell pollsters their ideal family size is less than two children, enough to replace themselves but not their partners. Worldwide, there is a 50 percent chance that the population will be falling by 2070, according to a recent study published in Nature. By 2150, according to one U.N. projection, the global population could be half what it is today.
That might sound like an appealing prospect: less traffic, more room at the beach, easier college admissions. But be careful what you wish for.