As I write this post, the World’s population has reached 8 Billion people. This has triggered a lot of commentary about overpopulation and out-of-control population growth.
The most disturbing commentary says that we need to drastically reduce the human population to save the planet.
But is the Earth’s human population growth really out of control?

This type of fear-mongering has been going on for centuries and first started with Thomas Malthus who in 1798 observed that food production growth was linear and population growth was exponential.
He predicted that population growth will far outrun food production which would result in mass starvation and death.
The thing is Malthus was NOT wrong in his observations. But nevertheless, there hasn’t there been a massive famine that wiped out 90 % of the human population as he predicted.
So if Malthus was right then why didn’t his predictions come true?
The reason why Malthus’s predictions didn’t come true was that he failed to account for technological change. At the time of his observations, the rate of food production was linear and the rate of population growth was exponential. But that was only a snapshot in time. And his predictions were over a period of time. This is a mistake many people make when making forecasts or predictions.
As the population grew, the demand for food naturally increased. And when the demand increases (without an equivalent increase in supply) the price increases. This price increase makes food more valuable and encourages farmers to capitalize on the increased price. Not only did production increase but so did the productivity of food production. Meaning that more food was being produced on the same amount of land. Malthus’s observations were true at the time but over time it turns out that food production grew exponentially and at a faster rate than the human population.
Malthus became notorious for this prediction error and people who later made similar claims are said to be a Disciple of Malthus or making a Malthusian Argument or falling for the Malthusian Trap.
Population Bomb?
Despite the fact that Malthus’s dire predictions didn’t come true, Dr. Paul Ehlrich (American Biologist and Stanford Professor) fell for the Malthusian Trap 170 years later, when he wrote The Population Bomb in 1968 with his wife Anne.

“The battle to feed all of humanity is over. In the 1970s hundreds of millions of people will starve to death in spite of any crash programs embarked upon now. At this late date nothing can prevent a substantial increase in the world death rate…“
— The Population Bomb (Wikipedia)
Paul and Anne predicted mass starvation and death and that nothing could be done to stop it.
Despite their predictions not coming to fruition they maintained their theory was sound but would take longer to come to pass. And perhaps the most disturbing is the population control measures advocated by Paul which include starving countries that don’t agree to implement population control measures.
Paul Ehlrich tweeted support for forced sterilizations in India and China and also supported the one-child policy in China.
Because the mainstream media loves doom and gloom stories, they were more than happy to amplify this message. Paul was courted by the media over the years and made many appearances on news programs, the tonight show, and many others.
It seems like the more dire his predictions are the more attention he gets – but the better off we Earthlings actually became.
The Bet
One of Paul Elhrich’s most vocal critics was Julian Simon, a professor of Business Administration at the University of Maryland. They sparred with each other in various articles until they decided to make a wager.
If Paul Elhrich is correct that population growth will result in increased scarcity of resources then the prices of resources should increase.
Ehrlich bet that the prices for the five metals of his choosing would increase over a decade, while Simon took the opposite stance.
Simon won the bet, as the prices for the metals sharply declined during that decade.
Paul Sabin wrote a book about this appropriately called, The Bet.
So if the population increased and correspondingly the demand for resources increases as a result, how is it possible for prices to go down?
If resources become more scarce the prices should go up, right?
How can the price of scarce resources go down if the demand goes up?
One of Julian Simon’s explanations to this question is that each new person added to the earth comes included with a built-in supercomputer (the human brain) that has the capacity to solve problems.
So the reason why resources are not becoming more scarce as more people are added to the world is that people are a resource!
Not only that but if the resources are sold on an open market as the demand increases the price will increase in the short run. This increased price causes previously unprofitable deposits of the resource to become profitable and the supply is brought back up. At the same time, the more expensive price encourages buyers to look for alternatives which will reduce the demand. All of these price responses cause the prices to fall over time while the population is growing.
In the book, Superabundance by Marion Tupy and Gale Pooley, they talk about when humans were living in caves thousands of years ago the world had the same amount of resources that it has today (minus any materials sent into space and any additions from meteors or space dust).
The number of atoms today is almost the same as back then.
The only difference is that now we have accumulated knowledge on how to manipulate and combine those atoms to build things and control our environment.
Because knowledge (technology) accumulates we have the ability to innovate infinitely.
Knowledge isn’t diminished or used up when shared or implemented.
And this is why from an economic perspective, in the long run, there is no such thing as resource scarcity.
So as the population has exploded (like a bomb) since Paul Ehlrich was born, so has our level of resource abundance. The Resource Abundance Bomb is even bigger than the population bomb.
Even though Paul Ehlrich was popular and became a doomster celebrity there were a lot of people that disagreed with his analysis.
Marian Tupy and Gayle L. Pooley wrote Superabundance in part to counter the damage done by Paul Ehrlich’s book.
Pierre Desrochers and Joanna Szurmak wrote a book in direct response to Paul Ehrlich’s book, The Population Bomb.
It is called POPULATION BOMBED! I have it on my Kindle and I’m reading it now. I’ll come back and add my thoughts once I finish the book.
But is the population going to continue to grow into the future? Will resource abundance continue to outpace population growth indefinitely? Or is there a point where we use up all of our resources and Paul Ehrlich’s (and Thomas Malthus’s) predictions finally come true?
Well, it turns out that population growth is decelerating.
The world’s population growth rate is stabilizing
Global population growth has been slowing for decades and is expected to peak this century. There are many reasons for this, including declining birth rates due to changing cultural norms, and increased access to contraception.
In the United States, Canada, Europe, Russia, China, and most other developed nations, the rate of population growth has fallen below replacement levels which is 2.1 children per woman. This means that most developed countries need to rely on immigration in order to maintain a stable population.
There are many reasons for the decline in the fertility rate:
- Changing cultural norms
- Longer life expectancy resulting in delayed fertility
- Increased economic opportunities for women
- Increased education and availability of birth control
- Reduced child mortality rates
- Urbanization
China’s One Child Policy and Cultural Norms

In China, the one-child policy restricted families to having only one child. This caused a lot of issues as the culture preferred at least one male per family. This led to families choosing to terminate female pregnancies and resulted in a skewed male-to-female population demographic.
But the one-child policy officially ended years ago and the fertility rate remains around one child per woman because it has now become a cultural norm.
So China is facing a major problem as the population ages and only half of the population is being replaced. The younger generation will have to support a disproportionally large elderly population.
Increased economic opportunities for women
As economic opportunities for women increase in the developing world, the opportunity cost of having children increases. And this decreases the ‘demand’ for children. The best way to reduce population growth is to increase prosperity. The richer the population, the lower the fertility rate.
Increased education and availability of birth control
As girls have increased access to sex education and birth control they are able to decide the best time for them to get pregnant and take more control. And as they participate more in the education system and therefore have marketable skills in the workforce they are choosing to have a career first and a family later.
When women have access to education and family planning, they tend to marry later and have fewer children. This has a ripple effect throughout the population, resulting in lower birth rates overall.
Reduced child mortality rates
Before the development of penicillin and the eradication of smallpox, measles, and other infectious diseases, the child mortality rate was more than 50%. This means that over half of your children would have died before the age of 5. In order to ensure you had surviving children you would have to have 4, 5, or more kids.
Now it is unlikely that you will lose a child and this has helped to reduce the fertility rate further.
Urbanization: More people are living in cities
Today, over 4 billion people around the world – more than half the global population – live in cities. This trend is expected to continue and by 2050 it’s projected that more than two-thirds of the world’s population will live in cities.
And this trend has a significant effect on the fertility rate.
When people live in rural areas and earn income by farming, children are an asset because they end up being free labor. More hands make for lighter work.
But when families move to cities all of sudden children become liabilities. They are much more expensive and therefore the “demand” for children declines.
Why is the population still growing if all these factors are slowing population growth?
If fewer people are being born than in the past we should have negative population growth, right?
Well, there are a few reasons why the population is still growing despite fertility rates falling.
- We are living longer.
- Population Growth Momentum
- Some regions still have a high fertility rate.
The increase in population is caused by longevity

One of the reasons that the population continues to grow is that life expectancy has increased. And at the same time, early mortality from disease and accidental death has decreased. So more of us are surviving for longer and living to an older age than in the past.
Population Momentum
When the previous generation had a high fertility rate, even if the next generation has a low fertility rate there will be a population momentum factor that continues to push the population higher.
For example, if there is a baby boom where women have an average of ten children each then the population will increase significantly. But if the next generation has only two children per woman there will still be significant growth as there are now more women having kids.
1st generation – 10 kids (50% are women)
2nd generation 5 x 2 = 10 kids
So it takes multiple generations to slow down population growth momentum.
Some countries still have high fertility rates

There are a few areas in the world that still have high fertility rates.
Some countries are hovering close to the 2.1 replacement level but in Africa, the fertility rate is much higher than replacement levels. But as Africa goes through industrialization the fertility rate should fall just as it has everywhere else.
We need to think about population shrinkage, not just growth
The world’s population is projected to reach approximately 10.9 billion by 2100, with annual growth of less than 0.1%. This means that population growth is not out of control and we need to think about population shrinkage, not just growth.
There are now more people in the world over age 65 than there are under 5!

The downside to population shrinkage:
- A shrinking population means less “human resources”
- A shrinking population means a lower standard of living for everyone (most people think the opposite is true)
- A shrinking population may NOT necessarily mean a reduction in emissions. In fact, it is more likely to increase pollution levels if the population becomes poorer as a result.
Can we continue to grow the population in a sustainable way?
The bottom line is that if the population continues to grow and we don’t change the way we do things then we will be in serious trouble.
We have been living unsustainably when it comes to carbon emissions and as we move away from fossil fuels and the plastic economy to a renewable and green economy we should be able to reduce our environmental footprint and continue to have a stable population.
There has been a negative externality when it comes to carbon. The economy doesn’t include the cost of carbon in the production process and the carbon emissions have to be “paid” by everyone after the fact.
If the price of carbon was incorporated into the price of the products that emit carbon in the production process then they would be relatively more expensive than products that don’t emit carbon. And this price signal will mean people choose NOT to buy products that pollute.
This is the rationale behind a carbon tax or tradeable emission permits.
Whether or not we implement more carbon taxes or a tradeable emission permit system the world has become anti-carbon. The best way is probably to put a price on carbon but governments could just regulate it away as well.
If you listen to the Great News podcast you have heard that there are many people working hard to solve all these problems and the tools we have to work on these problems are growing exponentially.
We have AI running models and helping to create new technology that will move us to a sustainable economy. And there are converging technologies that are causing exponential change in a lot of industries.
If we change the way we do things then we should be able to continue to have sustainable growth in our population and hopefully stop thinking of new people joining us on earth as “bad”.