The rate of population growth around the world is slowing, so much so that the 21st century could be the last where the numerical presence of our species increases year on year.
This is one of the highlights of the latest 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 predictions, it predicts that the world’s human population may never exceed 11 billion. This is of course a rather daunting upper limit, but well below what most people thought it would be just two or three decades ago.
The world’s population increases over time when women on average have more than two children, they have them earlier in life and these children live longer than previous generations. Of these three factors, only the last is currently contributing to an acceleration in population growth.
In contrast, the number of children per woman has fallen from a global average of 5.0 in 1960 to 2.5 today. And women have their first child much later in life. Although starting at different levels, these changes are happening all over the world, in rich and poor countries alike.
Most of the decline in the number of newborns is linked to the new role of women in society and the economy, and their increasing access to education, which causes them to postpone having their first child and to have less overall.
Economic development, migration to cities, secularization, cultural change and changing social expectations are also key factors.
The fertility rate has already fallen below 1.5 children per woman in some countries in Europe and East Asia, while it hovers around 1.8 in the United States. Demographers assume that 2.1 children per woman are needed for generational replacement since some women do not have children.
Even India, at 2.2, is approaching this threshold. And if you think the end of China’s one-child policy could change the trend in the world’s most populous country, consider that fertility is around 1.1 in South Korea and Taiwan, where such a policy never existed.
Most experts predict that the 1.7 rate in China will continue to decline as more people move to cities and women continue to seek education and job opportunities.
Meanwhile, the average fertility rate in Africa is 4.4, although it fell from almost 7 in the 1960s. In addition, life expectancy there is increasing faster than in the rest of the world. . Thus, Africa will one day rival Asia for the title of the most populous continent in the world, reaching 2 billion by 2039 and 3 billion by 2063.
As with any rapid and large-scale transformation, the demographic downturn presents both challenges and opportunities. In Europe, East Asia and the United States, the challenges will be twofold:
On the home front, the economics of aging will surely lead to political friction and even social conflict if health care and pension promises are not kept.
On the foreign side, these parts of the world will have to come to terms with 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 great doses of ingenuity and planning. The future of the region looks bleak unless its agriculture and education sectors become more innovative and productive.
Given the rapid adoption of mobile telecommunications and payments over the past decade, there is room for optimism. Africa continues to stun with its rapid 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.
The demographic slowdown holds enormous opportunities. The first may well be that the social and economic advancement of women leads to a more equal, balanced and vibrant world.
Perhaps the greatest benefit of all is that it will buy us time to deal with the problem of global warming. In fact, last October the United Nations Intergovernmental Panel on Climate Change warned in a report that decisive action must be taken over the next two decades to avert catastrophic consequences.
Overall, the demographic slowdown will help ensure a livable planet for future generations. Demography is not fate, 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 Dr. Felix Zandman professor of international management at the Wharton School of the University of Pennsylvania.