Will World Population Drop Far Enough, Fast Enough?

Tom Flynn

Full disclosure: I admire the New York Times and its commitment to cover the world in depth when so many news outlets have abandoned that mission. Still, the Times has its blind spots, among them a relentless natalism. The paper seems glued to the notion that human numbers (to say nothing of the economy) must always, always grow. Hence my delighted astonishment at the story atop the front page for Sunday, May 23, headlined “World Is Facing First Long Slide in Its Population.”

“Demographers now predict that by the latter half of the century or possibly earlier, the global population will enter a sustained decline for the first time,” wrote reporters Damien Cave, Emma Bubloa, and Choe Sang-Hun. (Notably AWOL from this story was Sabrina Tavernise, the demographics reporter who usually carries the Times’s water when it’s time to dismiss the idea of demographic decline and cheer for infinite growth on a finite planet.)

With few exceptions, the story reported, “the era of high fertility is ending.” More women enjoy access to education and contraception, while economic and social anxieties lead potential parents to delay pregnancy and reduce family size. “Even in countries long associated with rapid growth, such as India and Mexico, birthrates are falling toward, or are already below, the replacement rate of 2.1 children per family.” In 2019, South Korea’s fertility rate was 0.92, the world’s lowest, despite the government having spent more than $178 billion over fifteen years trying to cajole Koreans into having more kids.

“[A]ccording to projections by an international team of scientists published last year in The Lancet, 183 countries and territories—out of 195—will have fertility rates below replacement level by 2100.” Sometime between the middle and the end of the twenty-first century, Cave et al. predict, young workers will stop outnumbering older workers and retirees worldwide.

“A paradigm shift is necessary,” German demographer Frank Swiaczny, a former chief population analyst for the United Nations, declared. “Countries have to learn to live with and adapt to decline.”

It’s worth noting what this article did not mention: the possibility, under serious consideration by some scientists, that environmental pollutants such as hormone disruptors might be reducing human fertility. Even so, the causes the article allows for seem adequate to prompt the long-term slide in numbers projected.

For a dismally overpopulated world, then, this is news doubly worth celebrating. First, because the infamous population bomb may be defusing itself; second, because America’s self-styled newspaper of record stepped back from its characteristic stance of overpopulation denialism.

Well, for a day.

On Monday, May 24, the place of honor where the lead editorial goes (when there is one) served up a piece by tech reporter-turned-pundit Farhad Manjoo. Manjoo had shouldered the task of championing Times orthodoxy. “Growth is not just an option but a necessity,” he insisted in a column titled “We’re Running Low on Americans.” “[I]t’s not just that we can afford to have more people, it may be that we can’t afford not to.” For Manjoo, slower growth—to say nothing of purposeful population shrinkage—ushers in “a steady reduction in dynamism, productivity and a slowdown in national and individual prosperity.”[1]

I know other things that erode dynamism, productivity, and prosperity—like not having enough potable water, arable land, or food. But I digress.

Rational people know that unbounded growth on a finite planet is impossible. Sooner or later, any population trying to live that way must exhaust a necessary resource or foul its environment past the point of no return. That’s why expert opinion has sounded alarms about overpopulation ever since the 1950s. Global population (nearing eight billion as I write this)[2] is already far in excess of what the planet can sustain long term.

What Is the Optimum Human Population?

Writing in Free Inquiry, population commentator Lindsey Grant offered this summation in 2004: “[T]he optimum may be something like the numbers we passed around 1950: a world population of about 2.5 billion (40 percent of the present 6.4 billion) and a U.S. population of 150 million (half the present 293 million).”[3] Paul Ehrlich, whose classic book The Population Bomb launched popular concern for overpopulation in the 1960s, recently suggested that Grant’s estimate may be too high. In March 2018, Ehrlich told journalist Damian Carrington that “[t]he world’s optimum population is less than two billion people—5.6 billion fewer than on the planet today.”[4],[5] In this issue, columnist Gregory S. Paul offers an even more pessimistic estimate: “To get the human impact down to reasonable levels would require a global population of a few hundred million (or maybe down to zero).”

Despite the uncertainties, it’s all another way of saying (as I observed it in 2013) that “the way 7.3 billion humans[6] live and consume right now is pushing ecosystems toward calamity.”[7]

What Shrinkage Really Means

Doing something serious about human numbers would mean, well, doing something serious about human numbers. It would mean purposely orchestrating several successive generations of planned population shrinkage. We’d have to spend a century, perhaps longer, with dependent retirees continually outnumbering an ever-dwindling pool of younger workers.

That prospect terrifies conventional thinkers, because our societies have so long run on a certainty that growth must be unbounded with workers always outnumbering dependents. But that’s not a sustainable plan. “The best social and economic systems human beings have devised are all—let’s admit it—glorified Ponzi schemes,” I declared in 2007.[8]

Don’t take my word for it. Nobel laureate economist and former Obama Administration energy secretary Stephen Chu agrees: “The world needs a new model of how to generate a rising standard of living that’s not dependent on a pyramid scheme.”[9] Or ask the seventeen leading ecologists quoted by Carl Safina in his article in this issue: “humanity is running an ecological Ponzi scheme in which society robs nature and future generations to pay for boosting incomes in the short term. ”Economics journalist Nathan Lewis cuts to the heart of it: “The notion that a shrinking overall population naturally causes or leads to economic decline” is “[p]erhaps one of the silliest myths around today.”[10]

As the Times story by Cave et al. makes clear, demographic decline confronts us whether we want it or not, even though no central authority imposed it. “[T]he invisible hand may be pulling us back from calamity,” I declared in 2007. “There’s just one little problem: nobody knows how to make a shrinking polity run smoothly.”

If there’s a way to organize an orderly and humane economy whose population is steadily shrinking, we need to find it fast. Hey Elon Musk, why not peel off a few billion and assign several ivory towers’ worth of economists to crack this problem?

The Downside of Prosperity

Another aspect of today’s overpopulation crisis is, ironically, that past efforts to make society more inclusive and humane, many of them led by secular humanists, have largely succeeded. Across the globe, billions look forward to longer and healthier lives and aspire to live more like Americans. Sounds like a triumph for social justice—except that the biosphere can’t sustain the ever swelling number of Americans who already live like Americans. For billions more to live as profligately as Americans, consuming and polluting with abandon, would usher in results little short of apocalyptic.

It may be the moral dilemma of our age. On one hand, it smacks of cruelty to deny others the good life Americans enjoy. On the other, if all others join us atop the consumption pyramid, we and our newfound companions in prosperity will rape the planet utterly.

A more sensible path might be for Americans to live less profligately, thus modeling sustainable lifestyles for the multitude so enamored of our example. Of course, that involves sacrifices that many Americans are loath to make. Another sensible path, in my view, would be to minimize the number of people from other countries who actually become Americans. Statistics show that immigrants to the United States don’t just aspire to live like Americans; they learn quickly to consume, emit, and pollute just like the Americans they’ve become.

From the biosphere’s point of view, one of the very worst things any individual can do is to migrate from any other country to the United States.

If not for immigration, many demographers believe the U.S. population would already be declining, as in some Asian and western European countries. That’s why I have called in these pages for sharp reductions in immigration—not out of intolerant paranoia about changing ethnic makeup, but simply to move toward having fewer, rather than more, high-consuming, high-polluting Americans.[11]

Is the Good News Good Enough?

Fertility isn’t declining in a vacuum. We need to consider its context: a global climate that’s rapidly deteriorating in response to what we’ve already done to it. If Cave et al. are right, fertility decline will be obvious by 2050 and well-nigh irresistible by 2100. But do we have that much time? According to National Geographic’s Stephen Leahy, by 2100 “up to three in four people will face the threat of dying from heat” unless greenhouse gas emissions are sharply curtailed.[12] (See also Carl Safina’s article in this issue, “Avoiding a ‘Ghastly Future’: Hard Truths on the State of the Planet.”)

Though it’s not the whole solution, one fine way to have fewer greenhouse gas emissions is to have fewer human beings emitting them. That’s especially true at the top of the pyramid, where per capita emissions are highest.

It seems clear, then, that relying on the invisible hand to start reducing human numbers between 2050 and 2100 may not be enough. We’ll still need proactive strategies to seek purposeful reduction in population. And we’d better figure out how to make an economy whose numbers are declining work.

Wish us luck.

Notes

[1] These two articles generated pushback. To its credit, on Sunday, June 6, the Times ran no fewer than six letters that viewed a lower birthrate as something to celebrate. Two of them took issue with the natalism of Manjoo’s essay.

[2] 7,899,887,218 as of May 24, 2021, at 9:15 a.m. Eastern Daylight Time, and—need I add?—growing by about 215,000 persons per day. https://www.theworldcounts.com/challenges/planet-earth/state-of-the-planet/world-population-clock-live/story.

[3] Lindsey Grant, “Optimum Population.” Free Inquiry, August/September 2004.

[4] Damian Carrington, “Paul Ehrlich: ‘Collapse of Civilisation Is a Near Certainty within Decades.’” The Guardian, March 22, 2018. Ehrlich is among the scientists who take seriously the idea that chemical pollution might threaten human fecundity.

[5] Reminder: all references to current population refer to the levels existing in 2004 (in Grant’s quote) or 2018 (in Ehrlich’s).

[6] Now 7.899 billion humans. You get the drift.

[7] Tom Flynn, “Overpopulation, Immigration, and the Human Future.” FI, June/July 2015.

[8] Tom Flynn, “Beyond Ponzi Economics.” FI, December 2007/January 2008.

[9] Jeff McMahon, “The World Economy Is a Pyramid Scheme, Steven Chu Says.” Forbes, April 5, 2019. “Pyramid scheme” and “Ponzi scheme” are essentially equivalent.

[10] Nathan Lewis, “Economic Abundance with Shrinking Population: Why Not?” Forbes, August 28, 2014.

[11] Flynn, “Overpopulation, Immigration, and the Human Future.” Op. cit.

[12] Stephen Leahy, “By 2100, Deadly Heat May Threaten Majority of Humankind.” National Geographic, June 19, 2017.

Tom Flynn

Tom Flynn (1955-2021) was editor of Free Inquiry, executive director of the Council for Secular Humanism, director of the Robert Green Ingersoll Birthplace Museum, and editor of The New Encyclopedia of Unbelief (2007).