World Overall Birth Rates are Actually Declining – The Myth of Overpopulation
People have been talking about overpopulation for a very long time. It all really started around the end of the 1700s, when British economist Thomas Malthus outlined his theories in a paper titled, “An Essay on the Principle of Population.” In this book, Malthus looked at past population trends and basic ideas in ecology, and came up with some very pessimistic conclusions.
Basically, he saw that advancements in our ability to produce food tend to increase linearly, while the number of people that food has to sustain tends to increase exponentially. That’s bad news, because it means that sooner or later, the number of people in any given country is going to be higher than the amount of food that country can produce. When that happens, some combination of famine, war, and disease will decimate that country until the population has fallen low enough for the food supply to handle.
Malthus’s predictions made a lot of sense at the time, and over the coming centuries, a lot of people worried about what was going to happen when the world finally reached that awful max capacity. This worry was probably best illustrated in the 1973 movie “Soylent Green,” in which our society has been reduced to doing unthinkable acts in order to curb overpopulation. It was also popularized in the 1968 book The Population Bomb, which predicted mass famines in the face of runaway population growth.
And the thing is, theories like this seem pretty well-founded if you just look at humans as any other kind of animal. If there aren’t any factors like predators holding them back, all species’ population rates tend to increase exponentially until they hit something called a “carrying capacity.” This is the theoretical maximum population of a species an ecosystem is able to maintain, and a species’ population hovers around this level.
Sometimes it will get higher than the carrying capacity, but then factors like starvation will drive it back down below this magic level. The population will then grow again until it gets higher than its carrying capacity, and the same thing will happen again.
This is just the way nature works. It’s ruthless. Population sizes are held in check by death alone.
That’s the kind of future for humanity that thinkers like Malthus have been predicting for all these years. It’s a funny thing, though. All of these predictions always involve disaster right around the corner, usually within a couple decades or so. But strangely enough, it still hasn’t happened—and according to the numbers, it never will.
Why is this? Well, for a while it was because we just got a lot better at growing crops than anyone thought we could. Technology started shaping agriculture in a big way in the 1800s, and it hasn’t really stopped since then. For some time, that was the answer to our predicament. Our farms were keeping pace with our appetites, so we could keep putting off disaster for another couple years.
If that were all there was to it, though, the future of humanity would still be pretty bleak. There’s only so much possible living space, after all, and eventually we would start exhausting other resources on this planet, like water. Exponential growth is never sustainable.
But there’s one thing Malthus and all his followers didn’t account for: humans are very different from other animals.
We grew exponentially for a while, sure. But in the modern world, population growth rates have started slowing in a big way. Check out this graph of global fertility rates over the past few decades:
A sustainable population has a fertility rate of about 2.1. That’s a little over two births per fertile woman, or one birth per person in a society. As you can see, global fertility rates are well on their way to reaching that number. From the peak in the 1960s, those numbers have stayed on the decline.
The future of our species’ population is looking increasingly sustainable in every corner of the world. There are a lot of possible reasons for this.
For one thing, contraceptives have made family planning far more realistic than it was in the time of Malthus. Abstinence isn’t the only way to keep from having kids anymore, so since humans tend to follow nature’s call, the increase in accessibility and use of these measures has contributed greatly to balancing out the birth rate.
Also, there really aren’t many advantages to big families in the industrialized world. The cost of raising a kid has gone way up, and so have the drawbacks. Women, in particular, are increasingly delaying having kids as they pursue higher education and their own careers, and children can’t contribute to family incomes the way they could a couple centuries ago, when most people lived on farms.
The bottom line is, rising population rates are looking more and more like a thing of the past. After peaking at around six or seven children per woman, fertility rates get low and stay there. This isn’t just in a couple of select countries, either. In all countries, in all inhabited parts of the world, we’re seeing this trend repeat itself everywhere from Europe to Sub-Saharan Africa.
This whole process is speeding up. It took the UK 95 years to get its fertility rates from over six kids per woman to under three. That was back in the 1800s to early 1900s. Modern countries are moving a lot faster than that. South Korea achieved it in 18 years (1960-1978). Iran did it in just 10 (1986-1996).
The world is going to have a lot of challenges to deal with in the coming years, but overpopulation is not one of them. The numbers don’t lie. Mass famine is not inevitable, and we’re not doomed to crowd out the earth until there’s nowhere left to live. As the charts demonstrate, overpopulation is, in fact, a myth.
