Our global population is aging. The moment of peak youth on this planet was in 1972. Ever since then the average age on Earth has been increasing each year, and there is no end in sight for the aging of the world for the next several hundred years! The world will need the young to work and pay for medical care of the previous generation, but the young will be in short supply. Mexico is aging faster than the U.S., so all those young migrant workers who seem to be a problem now will soon be in demand back at home. In fact, after the peak, individual countries will race against each other to import workers, modifying immigration policies, but these individual successes and failures cancel out and won’t affect the global picture.
The picture for the latter half of this century will look like this: Increasing technology, cool stuff that extends human life, more older people who live longer, millions of robots, but few young people. Another way to look at the human population in 100 years from now is that we’ll have the same number of over-sixty-year olds, but several billion fewer youth.
We have no experience throughout human history with declining population and rising progress (including during the Black Plague years). Some modern countries with recent population decline have experienced an initial rise in GDP because there are fewer “capitas” in the per-capita calculation, but this masks long-term diminishment. But there can always be a first time!
Here is the challenge: This is a world where every year there is a smaller audience than the year before, a smaller market for your goods or services, fewer workers to choose from, and a ballooning elder population that must be cared for. We’ve never seen this in modern times; our progress has always paralleled rising populations, bigger audiences, larger markets and bigger pools of workers. It’s hard to see how a declining yet aging population functions as an engine for increasing the standard of living every year. To do so would require a completely different economic system…
Optimism arises from decreasing birth rates around the world. Education, health care, family planning, urbanization, and especially increased opportunities for adolescent girls and women are all highly correlated with lower fertility. Families are desiring and deciding to have fewer children. Increasingly they have the means and know-how to make those decisions. If fertility rates drop from 2.5 today down to 1.6 in the near future, then peak humanity will occur around 8 billion by 2025 and will actually decrease to 5 billion by 2100. Exponential patterns work going up and could also work coming down.
Environmentalists might applaud such a scenario—a planet at the turn of the next century with 2 billion fewer people than today—as it seems like fewer people would relieve some of the pressure on the planet’s ecosystems. The economic consequences of such a population decline, however, could be catastrophic in the short term. It is not clear that we can have economic growth with a declining population. If economies don’t grow, then paying off debt becomes an exponential burden unleashing a downward economic spiral. The collapse of our global economy is counter-intuitively also likely to be devastating for our global environment, as desperate people aren’t likely to care much about protecting the planet. And economic growth also helps drive the decisions of families to have fewer children. It seems we are in a triple-bind between containing population growth, protecting the environment, and growing economies. Big Problems!
The prospect of declining fertility also raises evolutionary concerns about the future of humanity on a soon to be child-scare planet. Children are literally the future of our species. Children humanize us. They inspire adults to be nurturing and future oriented. We need a planet with fewer children in a world that invests more in those few children, even though they may be someone else’s children. Fostering that kind of altruism and long-term commitment is a very Big Question.