Below-replacement fertility is now the norm throughout the Western world, including the US and Europe, and also in East Asia, including China, Japan, and South Korea. Even India has just slipped below replacement – Photo Getty
The Collapse of Fertility
By Nayyer Ali MD
The UN-released updated measures of global birthrates state that as of 2021 the global Total Fertility Rate (average number of children born per woman) had fallen to 2.2. That is just barely enough to keep human populations from shrinking. But this global average mixes two groups of nations, those with below replacement fertility and those with above to reach this average number.
Below-replacement fertility is now the norm throughout the Western world, including the US and Europe, and also in East Asia, including China, Japan, and South Korea. Even India has just slipped below replacement. In many of these societies, the TFR is catastrophically low. Spain is at 1.4, Greece at 1.3, Japan 1.3, China 1.1, and South Korea at a tiny 0.8. Basically, large numbers of women have stopped having children or only have one child. These extremely low numbers are causing populations to actually start shrinking as there are more deaths than births. In addition, the population is aging rapidly as more and more people live to old age but smaller numbers of children are born. Unless these trends are reversed rapidly, it will lock in much smaller populations. After one generation of low fertility, there will be many fewer women of childbearing age in the next generation, so even if they boost their fertility to replacement levels, the overall population will still decline. China peaked its population last year at about 1.4 billion, and projections are that China will shrink in half to about 700 million people in 2100.
The only regions of the world that still have above replacement fertility are the Arab nations, sub-Saharan
China peaked its population last year at about 1.4 billion, and projections are that China will shrink in half to about 700 million people in 2100 – Photo Financial Times
African countries, and Afghanistan and Pakistan. But even in these nations, the TFR has been dropping. Pakistan is at about 3.2, while Egypt is at 3.0 and Saudi Arabia is at 2.3. Afghanistan has dropped from 8 in 2000 before the US invasion, to around 3.8 today, reflecting significant social change in the 20 years of the US-backed government.
Sub-Saharan Africa still has much higher fertility rates, but they have come down from the 7-8 range in the 1980s. Nigeria is at 5, Tanzania at 4.5, and Kenya is down to 3.5. While the population is already shrinking in much of the world, it will continue to rise in Africa for the rest of the century.
Right now the global population is 8.1 billion. A few decades ago there was concern that this could explode to 12 billion by 2100. The collapse in fertility means this will not happen. There are several different estimates of where we are headed, but all call for much lower numbers. The UN thinks the population will peak at about 10 billion and start to decline starting in 2080 or 2090. Another major think tank, the IHME is projecting that the global population will peak at 9.7 billion in 2064, then slowly decline to 8.8 billion in 2100.
The consequences of this global fertility collapse will be tremendous. First, the lower total number of humans means that environmental pressures will be mitigated. Less people means less land needed for agriculture, less carbon emissions, and less pollution. On the other hand, large parts of the globe will face extreme labor shortages. We are already seeing this in places like Japan and South Korea. We may find robots and artificial intelligence providing many of our basic services from restaurant meals to caring for the elderly to picking fruit. Countries that are more open to immigration will be able to keep their total numbers more stable but will have to accept the arrival of newcomers who may have different ethnic, cultural, and religious backgrounds. In Britain, 30% of all babies are now born to Asian or Black parents.
What is driving the collapse in fertility? At the most basic level, it is improved access to modern birth control and female education. Whenever a society educates its girls, the fertility rate drops. Religious and cultural forces that favor larger families can overcome that to some extent, which likely explains the higher fertility rates in Pakistan than India for example, or the higher fertility of Orthodox Jewish communities vs secular Jews. But the trend is downward everywhere.
The really big question is not what happens to human populations in this century, but what will happen in the next one. If fertility remains below replacement for two centuries, human populations could collapse to less than 5 billion. Is there some bottom at which we will not shrink further? One driver of extremely low fertility is societies in which women are discouraged from having a career and a family. Societies that support and encourage working moms have higher birth rates. As the globe gets ever richer, perhaps finding work-life balance will become easier for young couples, and having two or three children instead of just one will become the norm again.
Science fiction has given humanity glimpses of what our future might look like. In many science fiction stories, humanity has spread across the galaxy living on planets scattered among the stars. But if we cannot even replace ourselves, what reason would there be for humans to leave this planet en masse? If we are not growing as a species from one generation to the next, there is no reason to spread out beyond our solar system. The Earth is enough.
