Population: There Are Way Too Many of Us

 David Quammen, in his book Spillover: Animal Infections and the Next Human Pandemic, described the human population as an “outbreak.”  That term is applied to any species that undergoes a rapid population increase.  All species live within an ecology.  When the species increases faster than the ecology can adjust to the increase, the ecology and the species will both suffer. 

“We have increased our population to the level of 7 billion and beyond....We live at high densities in many cities.  We have penetrated, and we continue to penetrate, the last great forests and other wild ecosystems of the planet, disrupting the physical structures and ecological communities of such places.  We cut our way through the Congo.  We cut our way through the Amazon.  We cut our way through Borneo.  We cut our way through Madagascar.  We cut our way through New Guinea and northeastern Australia.  We shake the trees, figuratively and literally, and things fall out.  We kill and butcher and eat many of the wild animals found there.”

“We multiply our livestock as we’ve multiplied ourselves, operating huge factory-scale operations involving thousands of cattle, pigs, chickens, ducks, sheep, and goats, not to mention hundreds of bamboo rats and palm civets, all confined en masse within pens and corrals, under conditions that allow these domestics and semidomestics to acquire infectious pathogens from external sources (such as bats roosting over pig pens), to share those infections with one another, and to provide abundant opportunities for the pathogens to evolve new forms, some of which are capable of infecting a human as well as a cow or a duck.”

Quammen was concerned about humans becoming more susceptible to infections that could ravage the population like the plagues of earlier history.  He wrote pre-Covid identifying the H5N1 flu virus (bird flu) as the greatest threat.  That virus is still around us, still generating mutations that may allow it to be easily communicable from human to human.  Its mortality rate is much higher than that of Covid-19 and has the potential to cause a much greater decline in population level. 

Outbreaks are not just susceptible to viral infection.  This source identifies three modes in which species outbreak is brought to an end: “destruction of resources, natural enemies, and unfavorable weather.”  As outrageously frequent extreme weather events beset us, there is little denial that the climate is changing, and little debate that human activities are causing it.  At a time when the population is still increasing, the warming Earth will soon render some locations unlivable by humans.  People will either die off or move to a cooler climate.  Migration will not help much because elevated temperatures mean lower food production.  How much lower is not easily predictable.  However, one should realize that any agriculturally useful land is already being utilized.  Heading North will not help much, if at all.

All these problems that torment us now could have been mitigated if the population had not been allowed to get out of control.  Also, any response to these events would be more easily implemented if we had fewer people to worry about.  It is interesting to note that—as if knowingly—people who are in a position to control their fertilities (the number of children being born), have almost unanimously voted to decrease the population.  Can this trend be of any benefit to us as we move into the future?

The United Nations (UN) has long had the responsibility for tracking the world’s population and the populations of nations.  It has had a good record in this endeavor but recently there has been criticism of it for not recognizing the rate at which national fertilities are falling.  Other organizations have stepped up with their own population projections.  Some of these alternate predictions are presented in The World of Population Projections.  This chart illustrates the potential variations to the year 2100.

The UN provides its best estimate in its “medium scenario, then possible high and low ranges.  Two other organizations present similar projections, and both tend to suggest lower peak populations and lower populations at 2100.  The UN’s most probable projection has the world population peaking at around 10 billion near the end of the century and slowly declining.  If so, we have about two billion more people to deal with.  It is interesting and significant to note that the lower fertility projections indicate that by 2100 the world population could fall back below its current value.  The term fertility is used here to represent the average number of children had by the world’s women.  A value of around 2.0 is necessary to maintain the population level.  The major difference in the population projections involve the future predictions of fertilities in African nations.  In many countries, particularly the wealthy ones, fertility has fallen well below maintenance level, with some already exhibiting declining populations.

Some believe that the issue of a world population growing too large will soon be replaced by concern about a population falling too fast.  A brief note in The Economist, The new Asian family, illustrated how quickly population is declining in several significant East Asian countries.  Cultural evolution seems to be the cause as both men and women exhibit less interest in marrying and raising children in their modern societies.

“In China, Japan, South Korea and Taiwan, Asians’ supposed commitment to conservative family life is collapsing…millions of young people are opting for looser, often lonelier and—in the East Asian context—less male-dominated arrangements. In a region that is home to over a fifth of humanity, the socioeconomic and demographic consequences will be vast, potentially destabilising and will shape millions of lives.”

“In Japan, where the shift first became evident, married couples with at least one child accounted for 42% of households in 1980, and single people 20%. That has flipped. In 2020 couples with children accounted for 25% of households, and singletons 38%. And the decline is continuing. Last year 17% of Japanese men and 15% of women aged 18-34 said they would not marry, up from 2% and 4% in the early 1980s, and China recorded its lowest-ever number of marriages, half as many as a decade ago.”

“The result is a plummeting fertility rate. South Korea’s, at 0.78, is the lowest recorded anywhere and Taiwan’s only slightly higher. Japan’s and China’s are just above half the replacement rate. China’s cruel one-child policy, now replaced by panicked officials with calls to have three, exacerbated its demographic squeeze. But as the regional picture shows, it would have happened anyway. The total population of the four East Asian countries is predicted to shrink by 28% between 2020 and 2075. 

This demographic trend is remarkable.  Using the UN’s most likely projections, South Korea will have a population in 2100 that is 47% of its current value.  For China, the equivalent value is 54%.  Falling population is not unique to East Asia.  This source indicates that Russia, Germany, Italy and Spain also belong in that category, although the rate of change is not as great—yet.

Governments uniformly face a declining population as a threat.  The immediate concern involves an aging issue with increasing numbers of old people and a decreasing number of young workers who can contribute to their support.  Consequently, many countries have wasted a lot of money trying to encourage people to produce more children. 

A declining population need not be a national disaster.  It could be viewed as an opportunity.  It will require developing new ways to support society.  For example, why put up with a system that leaves aged workers unable to support themselves in their final decades?  It does not have to be that way.  Instead of fearing technologies that eliminate human labor, we could be encouraging them.  A country like South Korea or Japan will survive its falling population because it must.  It could then possibly be in the best position to survive the planet’s uncertain future. 

Declining populations are occurring too late to stave off the worst effects of climate change, but encouraging such a strategy might be the best way to accommodate what is to come.