• Choose a category
• All
• Classic-Fiction

Most OECD countries have now passed through these stages and—except for those allowing high levels of immigration like the United States—have stabilizing or even falling populations. Most developing nations, however, are still in Stage 2 or early Stage 3. Thus, our run-up in global population is still under way.

Once a population enters Stage 3 its net rate of growth starts to slow, and this has generally been happening, beginning at different times and to varying degrees, for most of the world. On average, growth rates in developing countries have decreased from around +2.3% per year in 1950 to +1.8% in 2007. Expressed as “doubling times” (the number of years needed for a population to double), that means we have slowed from doubling our developing world population about every thirty years in 1950 to every forty years in 2007.

As we saw in Chapter 1, urbanization, modernization, and the empowerment of women push fertility rates downward, thus ushering in the final stage of the Demographic Transition. Put another way, the urbanization of society—if also associated with modernization and women’s rights—helps slow the rate of growth. There are, of course, exceptions to this tendency, but as these phenomena continue to expand throughout the developing world, the global population explosion so feared by Thomas Malthus and Paul Ehrlich is expected to decelerate. Already, in late-stage, low-immigration developed countries like Japan and Italy, and in regions like Eastern Europe, populations have not only stabilized but are falling. Assuming that fertility rates continue to drop as they are now, we are heading toward a total world population of around 9.2 billion in 2050, at which point we will still be growing but about half as fast as we are today.78

One of the most profound long-term effects of women having fewer babies is to skew societal age structures toward the elderly (the pulse of babies from population momentum is only temporary). That is precisely what has now begun, in varying stages, all around the world (improving health care, of course, also extends our life spans, thus increasing the proportion of elderly even more). Demographers agree that we are racing forward to not only a more urban world, but a grayer one. This, too, is unprecedented in the history of humankind. For 99.9% of the time we humans have existed on Earth, our average life expectancy was 30 years or less. Archaeologists have never dug up the prehistoric remains of anyone over 50.79

This aging will hit some places faster and harder than others. With a median age of 44.6 years80 Japan is the world’s most elderly country today. In contrast, the median age in Pakistan is just 22.1 years, almost half that of Japan. Pakistan is youthful; Japan is full of geezers. But both places will become grayer during the next forty years. By 2050 the median Pakistani age will rise twelve years to 34. Japan’s will rise another decade to 55.

When I was young I remember seeing magazine advertisements targeting people who planned to retire at 55. In forty years fully half of all Japanese will be at least that old. On the following page, a table shows how the graying trend will transpire for a few other countries over the next forty years.81

As seen plainly on this table from just sixteen examples, there are large age contrasts around the world today and even larger ones emerging in the future. Korea, Russia, and China will join Japan as the world’s great geriatric nations. Mexicans will be older than Americans. Median ages will be higher everywhere, but Korea, Vietnam, Mexico, and Iran will age radically, by fifteen years or more. Only our poorest, least-developed countries—like Afghanistan, Somalia, and the Democratic Republic of Congo—will still have youthful populations in 2050; and even they will be somewhat older than today.

This patchwork of wildly contrasting age patterns around the globe is especially driven by the timing of fertility transitions—when the baby booms and echoes happened, and most importantly,