A common concern about life extension is overpopulation, the idea that there are too many people in the world. Are we really headed for a global overpopulation meltdown, as some people believe? The United Nations’ World Population Prospects 2019 report suggests that while the global population will continue to rise for the next few decades, ultimately, that rise will plateau.
First things first: it’s population growth, not overpopulation
Whenever the topic of defeating age-related diseases comes up, there is inevitably someone who will cite overpopulation as an objection to healthy life extension and a reason why we should continue to let people become sick and die of diseases that science may be able to cure in the coming decades.
Overpopulation is a word that gives the simple phenomenon of population growth a negative connotation. It suggests that an increase in the number of living people will somehow be harmful to us in different ways, such as famine, scarcity of jobs, running out of resources, excessive population density, and harm to the environment.
However, from a global perspective, there is currently no overpopulation; there is simply population growth, which is not necessarily harmful by itself, and it is important to understand the difference between these two things.
The two most common themes accompanying this concern are usually that we will run out of resources unless we reduce the number of people on the planet or that there are too many people and we will harm the planet.
The first is something that could and is being addressed by shifting to sustainable methods of energy production, such as biofuel and renewable energy to supplement nuclear power. Other approaches that reuse resources, such as recycling instead of using landfills, are also part of the solution to this. There is also the most obvious: changing our societies so that we consume less and pollute less.
The second common theme, that too many people will harm the planet, has merit; there is, without a doubt, a maximum carrying capacity that the planet can sustain. To avoid reaching this point will require us to make societal changes, but as we will see later in the article, there are already ways of achieving this without the kneejerk reaction of people demanding direct population control.
What does the data tell us about global population?
The United Nations’ World population prospects 2019 was published recently, and we want to go over the key points that this data shows, as the situation is perhaps surprising and goes against the grain of what some people believe.
Here are some of the key points from the new report:
- Population Plateau – The data strongly suggests that, for the first time in modern history, the world’s global population is due to plateau by the end of the century. This is largely thanks to the decline of fertility rates. The report projects that by 2100, the global population will have reached 10.9 billion but with an annual growth rate at this point of less than 0.1%, which is dramatically lower than the current growth rate.
To give you an idea of how drastically lower this is, we can look at the past and present. Between the 1950s and today, the global population growth rate has been 1-2% per year, which saw total population rise from 2.5 billion to over 7.7 billion. So, by the time we reach the population plateau, the growth rate is likely to be dramatically lower.
- Fertility is falling – The fertility rate by 2100 is projected to fall to 1.9 births per woman, as compared to 2.5 currently. The replacement fertility rate (the rate that is necessary to maintain the population) is 2.1 births per woman, and the data suggests that fertility will go below this by 2070.The decline of fertility is due to a number of factors, including increasing access to higher education (in particular for women), industrialization/modernization, access to healthcare, reduced infant mortality, and increased life expectancy. We historically see a decline of fertility in every nation that has moved from developing to developed.This trend is almost certainly going to continue as the developing nations responsible for the highest population growth, such as parts of Africa and Asia, reach developed status and experience a corresponding decline of fertility. In fact, if people want the global population to level out sooner, then the logical course of action here would be to help speed up the development of the nations where fertility rates are highest. The sooner they develop, the sooner the fertility rate will begin to decline.
- The global median age is rising – In 1950, the median global age was just 24, today it is 31, and by 2100, it is projected to rise to 42. This means that between 2020 and 2100, the number of people aged 80 and above should rise from the current 146 million to 881 million.By the 2070s, there are anticipated to be more people aged 65 and older than the number of people aged 15; this historical first, in which the aged population outnumbers the young, is known as the silver tsunami. The main contributing factors to this increase of the global median age are the increase in life expectancy and the decline of fertility rates.This also makes a very strong case for developing therapies for age-related diseases. These therapies would keep people healthy, independent, and able to continue working and contributing to the economy rather than being sick due to age-related diseases and putting a burden on the healthcare system, which is already feeling a heavy strain; imagine how much worse it will get once the old and sick outnumber the young. It’s better to keep people healthy as they age, and rejuvenation biotechnology is a means to this end.
- The majority of population growth is coming from Africa – Taking a look at the UN population data, you can see that the main area of population growth is currently Africa. The report projects that Africa will continue to see high population growth for most of this century; again, this is the result of developing nations having higher fertility rates, which supports the idea that bringing this growth down sooner would require raising these countries up to developed status.The report projects that Africa will see its population increase from the current 1.3 billion to 4.3 billion between now and 2100. The majority of this increase will come from the developing nations located in sub-Saharan Africa. As the data shows, of the top 6 countries accounting for over half of the global population, five of them are located in Africa. Tanzania, Nigeria, the Democratic Republic of the Congo, Ethiopia, and Angola are projected to be in the top 10 countries by population by the year 2100. The sixth country is Pakistan.
- The European population will go into decline – Projections suggest that Europe will experience population decline by 2100; it is expected to peak at 748 million by this time. This may also happen sooner, and some European countries, such as Germany, are already on the road to decline.Even with increased immigration to Europe, the population decline will continue, as immigrant fertility typically decreases dramatically in the second generation . Other studies also show that the presence of immigrants does not compensate for a declining birth rate .
- Latin America will also face decline – The Latin American region, including the Carribbean, is anticipated to see population growth until it peaks at 768 sometime around 2058 before going into decline.
- Asia will grow but then go into decline – Asia is set to see an increase in its population, going from its current 4.6 billion and rising to an estimated 5.3 billion around 2055. However, following this period of growth, it is anticipated to go into decline.India is projected to continue growing until sometime around 2059 and hitting the 1.7 billion population mark, while China is likely to peak around 2031. Indonesia, the most populated country in Southeast Asia, is expected to hit its peak population by the year 2067.Interestingly, the populations of Japan and South Korea are ahead of the trend and are expected to go into decline from 2020 onwards; in fact, Japan has arguably already reached this point, according to some sources and recent news stories.
- Immigration will prop up population growth in North America – The UN data suggests that the United States will experience a population increase of 85 million leading up to 2100 thanks to immigration, which will keep the population growing steadily. A similar situation is anticipated in Canada, where immigration will bolster the falling fertility rate there.
- From 2020 onwards, 90 countries face decline – A stunning 32 European countries are projected to be in population decline by 2100. Half of the 50 countries comprising Latin America, including the Caribbean, are also projected to be in decline by 2100. The remaining countries in the 90 are from varying locations and are shown in the report.
- By 2100, over half the children born globally will be in Africa – Currently, three out of ten children born today are born in Africa; this is expected to rise to five out of ten by the year 2100. Nigeria, if it continues to follow current trends, is believed to have 864 million new children between 2020 and 2100.
While we should, of course, understand that this and similar population reports are only projections of what may happen based on expert assumptions about the most likely future scenarios for fertility, life expectancy, and historical trends, they have proven accurate in the past, so they serve as a good guide for the most likely future outcomes for population. If you would like to delve deeper into the data, then absolutely check out the full report and interactive datasets here.
It seems clear that rather than using population growth as a reason to object to technologies that aim to increase healthy longevity, we, as a society, should instead focus on where the bulk of population growth is coming from and doing something positive to help those regions develop faster.
If we can raise these countries up by giving them access to higher education, technology, industrialization, sanitation, infrastructure, medicine, and lowering child mortality rates, we will almost certainly see population growth decline, as has historically happened in all countries moving from developing to developed.
At its core, overpopulation as an objection to healthy life extension is based on flawed reasoning and a misunderstanding of population data. Quite simply, there is no reasonable excuse for allowing people to continue to suffer from age-related diseases, and population growth is a solvable problem that need not cost people their health and their lives.
 Nargund, G. (2009). Declining birth rate in Developed Countries: A radical policy re-think is required. FV & V in ObGyn, 1, 191-3.
 Camarota, S., & Ziegler, K. (2015). The Declining Fertility of Immigrants and Natives. Center for Immigration Studies.