When I was younger, one of the world’s most prominent and critical problems was the threat of overpopulation. It was reported not just as a problem worldwide but particularly in China, India, Mexico, and Nigeria. This fear was based on the idea that the set of resources, including food production, was limited in the growth rate. At some point, humans, which can reproduce exponentially, will run out of resources. And with the population multiplying, that growth would happen faster than we could support them with the current resources.
The problem of overpopulation was hypothetical in the 1550 – 1800s. There were still many areas that the population could expand into, and the worry of overpopulation was significantly reduced with the establishment of overseas colonies.
But in 1878, Thomas Malthus wrote an essay, “An Essay on the Principle of Population.” The essay lays out how human growth will reach a resource limit quickly. It makes sense that the writer was an economist because the rhetorical hedge prefaces everything they say “… at current rates…” and “… if nothing changes …” That is a very “traditional” economist's way of making an argument.
Scientific American helpfully summarized the impact of Malthus’ prophecy on contemporary science and policy.
On the negative side of the ledger are the policies derived from believing in the inevitability of a Malthusian collapse. “The power of population is so superior to the power of the earth to produce subsistence for man that premature death must in some shape or other visit the human race,” Malthus gloomily predicted. His scenario influenced some national policymakers to embrace social Darwinism and eugenics, resulting in draconian measures restricting particular populations' family size, including forced sterilizations.
Many people have reviewed Malthus’ theory and updated the ideas, nearly always agreeing with Malthus in the general sense, if not in the near term. So why was this assumption wrong 250 years ago? And is it still wrong? Debaters on both sides of the equation quote Malthus. Those who believe we are doomed to overpopulate and kill the planet quote Malthus’ projections. Even when Malthus’ projections about population are ignored, the effect of a never-ending growing population is used to infer other problems, like climate change and pollution, stem from his population theories.
The Argument
As I stated above, Malthus’ thesis is that a population can grow exponentially, but food can only grow incrementally. That is the gist of it. In Malthus’ time, the population was 1 billion people. It is now over 8 billion. Below, I have laid out various explanations as to why this has not happened yet. The italicized comment afterward is how a Malthusian supporter would respond.
1. The twin revolutions of industry and food removed the resource problem from humanity. We have found enough arable land because we have better methods, fertilizers, insecticides, and genetically modified crops to feed everyone. In fact, we have an excess of food every year. But, by using these chemically intensive methods universally, we are destroying the earth's ability to grow crops naturally. The standard seed varieties also make it easier for a single plant disease to wipe out the worldwide population of crops of a single type.
2. The Malthusian trap disproves itself now as the population 8 times larger than it was in Malthus’ time, with no decrease in the overall standard of living. Supporters of Malthus' conclusions would argue this is, decreasing standards of living occurring in poorer countries away from our eyes. The starving and hungry lower classes, particularly the global South, prove Malthus right. He didn’t say we would all starve but that our quality of life would fall as the population expanded too much.
3. Malthus was wrong, look around and see. The opposing argument here is to look at the results more holistically. Malthus was correct, but not in simple terms of food. Excessive pollution, leading to global warming, is caused by overpopulation.
“Limits to Growth” Updates
Since 1800, there have been arguments for and against Malthus’ key conclusion. One of the seminal works about the carrying capacity of the earth was the 1972 Club of Rome’s first report: The Limits to Growth (PDF version free here1).
Limits to Growth was a scientific investigation of the problems of overpopulation, income growth, pollution, global warming, cost of environmental degradation, and technological side-effects, presented in a non-technical format. It was released in 1972 and was the output of an extensive investigation by the world’s leading scientists, social scientists, and other experts.
The authors called themselves the “Club of Rome” and are still active today – Club of Rome website. Their 1972 projections had some major extrapolation assumptions which have been proven wrong to date. These included the limit of peak oil, agricultural advancements, and population growth. Their assumptions of income growth and pollution issues (including climate change) were much more correct.
Why were Malthus and the Club of Rome wrong on population?
Both Malthus and the Club of Rome estimated that population growth would continue more or less exponentially. This has not occurred.
Population growth rates began to fall in the industrialized countries in the 1960s. It was a slow descent from historic highs and was first viewed as an anomaly. When growth rates first fell, it was assumed that more prosperous nations had fewer children because they were no longer needed as workers to support their parents in their old age. Social Security in the United States and comparable European systems promised a more stable income in old age, and the birth rate fell.
Various more robust explanations have been proposed since 1972 to account for this reduction in population growth rate.
Available birth control. Readily available birth control is the most significant change. Birth control medications became available in the late 1960s. This was the first time women and couples could decide when and if they wanted children. It turns out that women do enjoy being able to decide when they become mothers.
Education requires more resources per child. Therefore, the fall in birth rate reflected the cost of raising a child. In developing and less developed nations, the more education a child has, the more successful they and the family will be.
Infant mortality rates fell. Couples needed fewer children to ensure that some reached adulthood.
Life expectancy rose worldwide from about 53 years in 1972 to about 77 years today. Extended life expectancy drove lower birth rates.
Were Malthus and the Club of Rome’s projections on resources wrong?
The “correctness” of Malthus’ and the Club of Rome’s arguments about the carrying capacity of the earth does seem to be wrong. We looked at the population side of the equation in the last section. Now, let’s look at the resource side of the argument.
The Club of Rome investigated various resources and delimited their availability in the future. Their conclusions were only partially fulfilled on the resource side of the equation. Mainly because new methods of resource extraction have changed the Malthusian dynamics. Two of the primary resource limitations cited were food production and energy production.
Agricultural production has grown to the point where more food is generated today than is needed by the world’s population. There are still discrepancies between food availability and location, particularly in less developed nations. This is a heartless way of saying poor people and people in poor countries have a tough time buying food, even though there is more than enough.
Oil and energy production were also considered limiting factors cited by the Club of Rome. They foresaw a revolution in clean energy production via nuclear power after “peak oil.” Peak oil, as an idea, resonated with the world until the widespread use of fracking. Fracking has unlocked more oil and natural gas, albeit with some devastating consequences in places.
Additionally, we have avoided the peak energy trap by adapting to renewable energy like solar, wind, and water power, in addition to nuclear power.
From the population side of the equation, we have seen previously that the expected growth rates were not met and are slowing down in some countries to an alarming degree.
So we’re aces, right?
Have we broken the Malthusian Trap?
No.
Perhaps more explanation is necessary.
This is where I say that the following is my opinion only. It is true that we have reduced the rate of population growth and may reduce the world’s population at some point this century. And we have increased the carrying capacity of the world as it is necessary. That seems to prove we have overcome the issues of Malthus and the Club of Rome.
But it is a disservice to look at this projection at the surface level. Increasing the earth’s capacity has led to problems that overwhelm the positive effects in the long term. Producing more food and energy has destroyed much of the environment and even more of the “natural” environment.
For example, the American Great Plains has transformed from a natural prairie to thousands of miles of farmland. To maximize outputs, we have depleted the land and turned to artificial fertilizers. We have depleted aquifers that took millions of years to grow. I am not saying this is wrong, but there are consequences. A monoculture on the plains exposes our food supply to disruption when the balance is changed, as is happening with climate change. The fertilizers poison some water supplies, and the demands on water for crops and people vastly outstrip the replacement levels. These limitations have spread around the world as intensive agricultural techniques spread. And these techniques are necessary to feed our population, so they are very difficult to reverse
Also exceeding projections, energy production has increased yearly, and pollution is not the threat it was considered. On the other side of this scale, increased energy production has driven greenhouse gases through every expected limitation. Because early warnings of dire consequences did not come true, it was possible for years to pretend this was not a severe problem. Profit motives continue to drive some politicians and corporations to claim that climate change is natural and not an issue. It hasn’t been until the last few years that climate change has become unmanageable and deadly. And yet, even now, energy generation and use are expanding and driving further greenhouse emissions.
Summary
We have disproven some of Malthus’ theories. The population does not grow exponentially when people have a choice - readily available birth control provides that choice. We can produce enough food for everyone.
However, Malthus’ parallel conclusion was not just that we might not have enough food for people. But also, that population growth will mean an increased drop in the standards of living. Regarding this argument, our initial results gave sense to a constant rise in living standards, proving Malthus’ argument wrong. But today, the effects of overpopulation have manifested. Climate Change threatens vast parts of the globe, not just theoretically but in action. Furthermore, these changes have a more significant impact on poorer countries and people.
There are myriad other Malthusian problems: soil degradation, significantly reduced natural ocean fisheries, pollution that kills thousands worldwide yearly, and even authoritarian and fascist governmental growth. These problems have resulted from population growth and our focus on quick fixes.
To be honest, I don’t see a long-term solution that could actually be implemented. Americans and Europeans will fight any reductions in the standard of living in their countries. Developing nations strive to increase their standard of living in the same way we did, only to be told they are contributing to climate change. These nations point out it is entirely unfair of developed countries but have no way to force change. We struggle along.
Credit to Dartmouth Library