There’s No Reason to Worry About Overpopulation

Have you ever heard of Thomas Malthus? He was an 18th-century British economist who was famous for predicting that human beings would inevitably pop out babies until we overpopulated the earth, ran out of food, and started starving to death:

Thomas Robert Malthus was an influential British economist who is best known for his theory on population growth, outlined in his 1798 book An Essay on the Principle of Population.

In it, Malthus argued that populations inevitably expand until they outgrow their available food supply, causing the population growth to be reversed by disease, famine, war, or calamity.

He is also known for developing an exponential formula used to forecast population growth, which is currently known as the Malthusian growth model.

In other words, Malthus noted that the human race was on top of the food chain across the planet, assumed our population would grow almost exponentially and that eventually we’d run out of food and starve. Given that this sort of thing has happened to animals in certain areas and that it was 1789, this wasn’t a bad hypothesis.

However, it did turn out to be wrong. There are two things we can attribute that to.

The first takes us back to a rather famous bet between economist Julian Simon and environmentalist wacko Paul Ehrlich that happened in 1980.

Back then, Ehrlich was STILL getting lots of attention while pushing the Malthusian idea that the planet was going to become overpopulated long past what should have been the sell-by date for that idea. After all, the population of the planet had more than quadrupled in the time since Malthus introduced his theory. Yet and still, there really wasn’t much evidence that it was correct. In any case, Simon thought Ehrlich was wrong and proposed a bet to prove it:

The biologist at the heart of this bet was Paul Ehrlich at Stanford. He wrote a best-selling book in 1968 called The Population Bomb. It was so popular he appeared on The Tonight Show with Johnny Carson.

He told Carson, "There are 3.6 billion people in the world today, and we are adding about 70 million a year. And that's too many. The very delicate life support systems of the planet, the things that supply us with all of our food, with ultimately with all of our oxygen, all of our waste disposal are now severely threatened."

…Both Ehrlich and Simon enjoyed being provocative. Ehrlich started a movement called "Zero Population Growth." He got a vasectomy to set an example. And he proposed a tax on diapers to keep population in check.

Simon took to wearing devil horns on his head when giving talks.

Paul Sabin, a historian at Yale, told the story of this famous bet in his new book The Bet. And Sabin says Simon's side never really got as much notice as Ehrlich's — and that, it seems, is why he proposed the bet.

Simon proposed that they bet on what would happen to the price of five metals — copper, chromium, nickel, tin, and tungsten — over a decade.

And the logic was that these metals were essential for all kinds of stuff — electronics, cars, buildings. So, if Ehrlich was right, more people on the planet would mean we would start running out of stuff, and the price of these things should go up.

But, if Simon was right, the markets and human ingenuity would sort things out, and the prices would stay the same or even go down.

…Those next 10 years, from 1980 to 1990, crept by. The world population grew by 800 million people. Then it was 1990. And they tallied it up. Simon, the economist, decisively won. Prices for the five metals went down by an average of 50 percent.

One of the reasons the prices dropped was just what Simon said. The catastrophe Ehrlich was predicting just did not happen. People invented substitutes, like companies switching from aluminum to plastic for packaging.

Incidentally, although Simon’s general thesis was correct, he certainly COULD HAVE lost this bet over the short term because capitalism is a fickle mistress.

Perhaps new uses for one of those metals could have caused a spike in demand beyond the production capacity and thus price increases would have occurred or alternately, government regulations could have made it harder to acquire. A cheaper alternative to one of the metals could have come on the market and thus, mining of the metal might have declined causing the price to soar even with lesser demand – let’s just say that there are a lot of moving parts involved.

Still, generally, if the demand is high enough and supplying it is profitable enough, humans will find a way. So, it goes with food. Farming methods have improved. Transportation has gotten better and more efficient. Here in the United States alone, we receive fresh vegetables from 125 different countries.

Today, the world is still 8 times bigger than it was in Malthus’ day and we’re still feeding, clothing, and supplying the planet far, far better than we did throughout most of history.

The other reason that the human population has grown considerably but hasn’t raged out of control is a bit more recent, unexpected, and mysterious. Simply put, as prosperity spread, people stopped having as many children. In fact, the numbers dropped so much in many nations that they do not have enough children to maintain their populations and immigration is the only way to keep them from shrinking:

In 2000 the world’s fertility rate was 2.7 births per woman, comfortably above the “replacement rate” of 2.1, at which a population is stable. Today it is 2.3 and falling. The largest 15 countries by GDP all have a fertility rate below the replacement rate. That includes America and much of the rich world, but also China and India, neither of which is rich but which together account for more than a third of the global population.

There doesn’t seem to be any single factor that explains this, but a lot of things are probably playing into it, depending on the country you’re talking about. Certainly, here in the US, for example, fewer people are getting married and they’re getting married later. Birth control and abortion play a big role. Less religious people tend to have fewer children and children have turned from an economic benefit to an economic cost.

Also, one you seldom hear discussed that I believe is a big factor is that our home entertainment options have grown so dazzling that they’re simply leading to people staying at home a lot more and you typically aren’t going to meet the love of your life while you’re at home playing video games or watching a movie.

Whatever the case may be, depopulation brings its own set of problems with it, some of which we can see in cities and states that lost a great deal of residents during COVID. The fewer people there are, the less taxes that are coming in. A shrinking population can also lead to decline and blight, instead of moving towards a brighter future. See Detroit for a great example of how this plays out:

What it all means is that the population of the Earth is still growing, but seems likely to level off and even slightly decline within the next hundred years:

Of course, there are still people out there beating that same old drum that Malthus was about the human race being headed towards disaster because we’re going to overpopulate the world, even though there is very little if any real evidence that they’re right. Quite naturally, the charlatans like Les Knight of the Voluntary Human Extinction Movement that push this argument today have weaved global warming into the mix.

Knight, 75, is the founder of the Voluntary Human Extinction movement, which is less a movement than a loose consortium of people who believe that the best thing humans can do to help the Earth is to stop having children.

Knight added the word “voluntary” decades ago to make it clear that adherents do not support mass murder or forced birth control, nor do they encourage suicide. Their ethos is echoed in their motto, “May we live long and die out,” and in another one of their slogans, which Knight hangs at various conventions and street fairs, “Thank you for not breeding.”

On November 15, the Earth became home to a record 8 billion human beings. Despite declining birth rates, the number is forecast to peak at 10.4 billion in the coming decades, in large part because of increases in life expectancy and decreases in child mortality.

Knight is among those who believe that overpopulation is a main factor in the climate crisis, but that idea can be fraught:

...Yet Stephanie Feldstein, director of population and sustainability at the Center for Biological Diversity, said while greater human longevity and health were good things, they have come at a cost to other living things on the planet.

As the human population doubled in the last half-century, wildlife populations declined by 70 percent. Although lowering fertility rates today will not change emissions in the short term, she said surges in the human population would put increasing pressure on dwindling natural resources and the intricate web of animals, birds, and plants that depend on them.

“The loss of biodiversity can be just as devastating as it unravels the ecosystems we need to survive,” Feldstein said. “We’re already using nearly twice as many resources as the Earth can replenish in a year.”

...But it is rare to find anyone who publicly goes as far as Knight, who never had children and got a vasectomy in 1973 at the age of 25. Beyond advocating for universal access to birth control and opposing what he calls reproductive fascism, or “the lack of freedom to not procreate”, Knight said that despite our many achievements, humans are a net detriment to the Earth.

“Look what we did to this planet,” Knight said during a chat in his sunlit backyard one warm morning this fall. “We’re not a good species.”

...“People mention music and art and literature and the great things that we have done. It’s funny they don’t ever mention the bad things we’ve done,” he continued. “I don’t think the whales will miss our songs.”

This sort of feckless nihilism seems to be more of an aberrant trait in some unfortunate people’s nature than anything driven by real-world conditions. It is true that the planet would be more pristine if human beings no longer existed, but there would be no point in its existence. It’s a bit like John Shedd’s famous quote:

Overall, although we’re far from perfect, we’ve gotten much better at cleaning up our messes as a species, there’s very little real, scientific evidence that manmade global warming is a significant threat, and we have every reason to think that the planet can support not only the current levels of human life but the levels we’re likely to reach even in the early 22^nd century. There are lots of things in the world to be concerned about and perhaps even a little pessimistic about, but overpopulation is not one of them.

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