The pace of population growth in the world is slowing down, so much so that the 21st century may be the last in which the numerical presence of our species increases from one year to the next.
This is one of the highlights of the most recent revision of the World Population Prospects, released earlier this week by the United Nations.
Using what they call the “medium variant,” or the midpoint of the most likely forecasts, it predicts that the global human population may never exceed 11 billion. That’s of course a rather daunting upper limit, but much lower than what most people assumed it would be just two or three decades ago.
The world’s population grows over time when women on average have more than two children, they have them earlier in life, and those children live longer than previous generations. Of these three factors, only the latter is presently contributing to an acceleration in population growth.
By contrast, the number of children per woman has plummeted from a global average of 5.0 in 1960 to 2.5 nowadays. And women are having their first child much later in life. Although starting at different levels, these changes are taking place everywhere around the world, in rich and poor countries alike.
Most of the decline in the number of newborns has to do with women’s new role in the society and the economy, and with their increasing access to education, which leads them to postpone having their first child and to end up having fewer overall.
Economic development, migration to the cities, secularization, cultural change and shifting social expectations are also key factors.
The fertility rate has already fallen below 1.5 children per woman in some European and East Asian countries, while it hovers around 1.8 in the United States. Demographers assume that 2.1 children per woman are needed for generational replacement given that some women have no children.
Even India, at 2.2, is getting close to that threshold. And if you think that the end of the one-child policy in China may change the trend in the world’s most populous country, consider that fertility is about 1.1 in South Korea and Taiwan, where no such policy ever existed.
Most experts predict that China’s 1.7 rate will continue to fall as more people move to the cities and women continue to pursue educational and job opportunities.
Meanwhile, the average fertility rate in Africa is 4.4, although it has declined from nearly 7 in the 1960s. Moreover, life expectancy is growing faster there than in the rest of the world. Thus, Africa will one day rival Asia for the title of the world’s most populous continent, reaching 2 billion by 2039 and 3 billion by 2063.
As with any swift, large-scale transformation, the demographic slowdown brings about both challenges and opportunities. In Europe, East Asia and the United States, the challenges will be dual:
On the domestic front, the economics of ageing will surely lead to political frictions and even social conflict if health care and pension promises are not kept.
On the foreign side, those parts of the world will need to accept the geopolitical, and perhaps military, implications of their numerical decline. Increased immigration would partially deflect both challenges.
Africa will face the most formidable test. Feeding and educating hundreds of millions of young people will require large doses of ingenuity and planning. The region’s future looks gloomy unless its agricultural and education sectors become more innovative and productive.
Given the quick adoption of mobile telecommunications and payments over the last decade, there is room for optimism. Africa continues to stun with its swift technology-driven transformation. And let’s not forget that six of the 10 fastest-growing economies in the world last year were in sub-Saharan Africa.
There are huge opportunities embedded in the demographic slowdown. The first might well be that women’s social and economic advancement results in a more equal, balanced and vibrant world.
Perhaps the biggest benefit of all is that it will buy us some time to cope with the problem of global warming. In fact, last October, the United Nations Inter-Governmental Panel on Climate Change warned in a report that decisive action needs to be taken over the next two decades in order to avoid catastrophic consequences.
All in all, the population slowdown will contribute to securing a livable planet for future generations. Demography is not destiny, but it surely matters.
Mauro F. Guillén, a sociologist by training, is the Anthony L. Davis director of the Joseph H. Lauder Institute of Management and International Studies and the Dr. Felix Zandman professor of international management at the Wharton School of the University of Pennsylvania.