A central tenet of the population-panic school is that throughout the world, as Chris Hedges wrote last year in his usual Jeremiah-meets-angry-beehive style, we are heading for "an age of extinction and desolation" because "population growth is exploding." This is false: Environmental desolation may indeed be around the corner, but population growth is not the reason.
In fact, population growth rates are in free fall. They have been dropping for nearly 50 years. Thanks to improvements in health care and housing, nation after nation has passed through the "demographic transition,'' in which, as the mathematical biologist Joel Cohen once said, people "realize that their children were surviving to adulthood, so they didn't need to give birth to 8 children in order to have two around to take care of them in their old age.'' The more-than-exponential growth rates of the 20th century will never be seen again. They were a one-time fluke.
In 1950, the world's overall fertility rate was 5 children per woman per lifetime. Today it is 2.26, and dropping. The trend is global, encompassing nations as different as Iran (7.0 in 1965, 2.1 in 2005), Thailand (6.5 in 1968, 1.64 in 2006), Paraguay (5.91 in 1970, 3.8 in 2008) and Togo (7.05 in 1970, 4.85 in 2008). Of course, there's a big difference among those numbers. "Replacement rate'' fertility for a developed country is 2.1 children per woman per lifetime (it can be as high as 2.3 in poorer nations), so Thailand and Togo are on very different paths for now. The downward trend, though, is worldwide.
If that pattern continues (and for now demographers see no reason to expect otherwise), the population of the Earth (now 6.7 billion) will peak in 2050 at somewhere between 7.8 and 12 billion, according to United Nations Population Division estimates. (Nine billion people, its medium-fertility projection, is today's best guess.) After mid-century, population will decline, the UN estimates. As best as demographers can tell, there is no "population bomb." Or, rather, it has already gone off.
Instead, the most striking contemporary consequence of the demographic transition is a push in more and more nations to increase their birth rates, for reasons both logical and politically popular. The last century's demographic changes didn't just falsify the notion that we're "breeding ourselves into oblivion." They also made it politically impossible to enact policies based on this belief.
Here's why: When an industrialized nation's population shrinks, fewer and fewer working-age people have to support more and more retirees. China, for example, now has about six working-age people for each retired person. On current trends that ratio will be 2 workers per retiree by 2050. That's a prescription for labor shortages, falling production, and political uproar as promised pensions and health-care for the elderly become impossible to pay for.
As Mara Hvistendahl reported last month in Science (you can read a pdf of her piece here) a group of concerned Chinese demographers is working to change that country's "one-child" policy, which currently limits more than 60 percent of the population to one offspring only. (The policy doesn't affect everyone because of a byzantine system of exceptions and exemptions, as described here, in a 2007 article in Population and Development Review. It was, amazingly, the first systematic analysis of the policy by demographers.)
Earlier this month, in this lucid post, one of the authors of that review, the sociologist Wang Feng, summarized the "imminent and inevitable" crisis facing China as a consequence of its falling growth rate. He is one of the demographers who think, as he told Hvistendahl, "it's time to start experimenting and looking at how to phase out the policy."
Meanwhile many, if not most, rich nations are already nudging their people to have more children. The French state, for instance, is typical in its incentives: it pays in full for citizens' infertility treatments, and gives 10 weeks additional paid maternity leave for a third child than for the first two. And France's fertility rate, 1.9 births per woman per lifetime, is already near the crucial ``replacement rate'' of 2.1. Many other industrialized nations, including Japan, Italy, Spain and Russia, fall around 1.3, so they're nudging harder. Since 2006, for instance, Russian parents with one child receive $9,200 in ``baby money'' for each additional offspring.
As long as the world is organized into nation-states, politicians have little choice. If Italians keep reproducing at a rate of 1.3 children per woman, there will be no more Italians (at least, not Italians-by-descent) in 2110. What could be dafter, then, than a rich-nation "think tank" proselytizing for drastic cuts in population?
The political unpopularity of national extinction isn't the only source of resistance to anti-fertility arguments. There's also the innate psychology of a social species: Unless you are very frightened or very privileged or very educated in a particularly technocratic point of view on the world, you will have a hard time seeing the birth of a human infant as bad news. Population-panic groups try their best to get around this, but their own data show how hard it is to budge the public.
On its website, for instance, the Optimum Population Trust touts a 2009 poll it commissioned in the United Kingdom, in which 72 percent of respondents said they agreed with the claim that there are just too many human beings on Earth, and 70 percent found their own country overpopulated too. I downloaded the complete data, in spreadsheet form was struck by a different number: The 65 percent who said their own area needed only "slightly fewer" people, or was just fine at its current density, or could actually use a higher population.
In other words, these poll respondents were easily convinced that someone else's population is too high. (Their favorite solution to the U.K.'s population issues, chosen by 69 percent, was reductions in immigration). When it comes to their own family, friends and neighborhood, though, a majority don't feel crowded. This is why, I think, talk of "overpopulation" lends itself to the crudest forms of Us-Them rhetoric. It's always someone else's population, somehow, that's "over" the natural limit. About which more in the next few days.
Of course, global population-reduction could be a great idea, even if it isn't politically feasible. I don't think that's so. That's the subject of the next post in this series.
Baochang, G., Feng, W., Zhigang, G., & Erli, Z. (2007). China's Local and National Fertility Policies at the End of the Twentieth Century Population and Development Review, 33 (1), 129-148 DOI: 10.1111/j.1728-4457.2007.00161.x