Estimates of population growth during the coming decade have sparked worries. Liam Glen writes on the dynamics of overpopulation and why humanity is unlikely to pass its carrying capacity.
It was known already that Earth’s population is growing. But a recent estimate by Germany’s Foundation for World Population that there will be 7.75 billion people by the New Year seemed stark enough to make headlines. This has once again ignited worries that there may soon be too many people for the planet to support.
These fears are as old as the modern era itself. Thomas Malthus argued in 1798 that population growth would inevitably overtake food production, and models by Paul and Anne Ehrlich in the 1960s reignited these concerns in the twentieth century.
In each instance, these predictions were proven false. But the idea that a growing population will strain Earth’s limited resources still holds. At times, it leads to the uncomfortable prospect of government policies to control population growth.
It would be foolish to dismiss the issue entirely, but there is good reason to think that today’s fears about overpopulation are, as in times past, overblown. Problems may come up, but due to human innovation and demographic trends, a catastrophe is highly unlikely.
The Looming Carrying Capacity
When the topic of overpopulation emerges, the first concern that comes to many minds is running out of basic resources like food and land. But this is not the most probable scenario.
On a global scale, lack of space is the least of our problems. Many countries – such as South Korea, Japan, and the Netherlands – get along fine with high population density. Others still have plenty of room. Overcrowding can be an issue in certain areas, but it is not an issue on the Earth as a whole.
Meanwhile, agriculture is a field of constant innovation. At this point, there is already more than enough food to adequately feed every person. The fact that there still exists people who cannot afford to eat is less a symptom of resource scarcity than of failed public policy.
Even at current growth rates, humans will be able to survive for the foreseeable future. But that does not mean that everyone will be able to thrive. People around the world live in massively different economic conditions. Developed standards of living take up a much larger amount of electricity and consumer goods which strain the natural environment, most notably through fossil fuel emissions, which have already far surpassed sustainable levels.
As poverty declines, each person will have a larger ecological footprint. By one estimate, if everyone on Earth consumed as much resources as the average American, there would only be enough for 1.5 billion people.
But it is for this exact reason that sustainable development is becoming a field of its own. Renewable energy will allow us to get the same utility while massively reducing fossil fuel emissions. Advancements in other technologies are similarly allowing more to come from less. While challenges will emerge in ensuring that every person has a decent quality of life, there is not yet cause for defeatism.
At the same time, though, it is foolish to think that population growth can continue forever. Even if each individual person had a miniscule ecological footprint, this would add up as the population ballooned in the tens of billions.
Barring the possibility of self-sufficient colonies on other planets, Earth would eventually run out of enough resources for everyone to live comfortably. The current rate of population growth is unsustainable.
Final Stages of Demographic Transition
Thankfully, it is almost certain that the world’s population will not continue growing at its current rate. History has shown that economic and technological development leads to demographic transitions. As modern medicine and sanitation lead to longer lifespans and lower infant mortality rates, population growth explodes.
Then, however, a number of factors intervene. As people know that more of their children will survive, they have fewer. As education becomes widespread, there is no longer an incentive to have children for the purpose of sending them to work. As women enter the workforce, they are less likely to have large families. As contraceptives become widespread, couples can control when they reproduce.
Inevitably, falling birth rates stabilize population growth. This happened first in Europe and North America. Now the transition is reaching its final stages in many parts of Asia. UN estimates, which have traditionally been reliable, expect world population to peak around 11.2 billion in 2100 before stabilizing. Much of this growth will happen in Africa, which is still going through the middle stages of the transition.
It would be closed-minded to ignore concerns about overpopulation. But it would also be irrational to incessantly worry about the issue. Problems will emerge, but the idea that radical action is needed to curb population growth is unfounded. Instead, the cures – sustainable development, gender equality, and family planning – are things which we should be striving towards anyway.