The U.N. Says World Population May Top Out at 10.9 Billion Before 2100. Other Demographers Say It'll Be Much Lower.

Thanks to global expansion of reproductive freedom, actual population growth is likely to be less and peak around the middle this century


In its 2017 World Population Prospects report, the United Nations projected that world population would reach 11.2 billion by 2100 and continue to grow from there. The U.N.'s new report, however, finds that while "a continued increase of the global population is considered the most likely outcome, there is roughly a 27 percent chance that the world's population could stabilize or even begin to decrease sometime before 2100."

These projections are too high
Projecting the end of global population growth

Why the change in projections? Because the global average fertility rate—which is the number of children each woman is expected to have over the course of her lifetime—is falling steeply. That rate stood at 5 per woman in 1960 and has now dropped by 2.5 per woman. Replacement fertility is generally defined as 2.1 children per woman. During the same era, global average life expectancy increased dramatically, from 52.5 years in 1960 to 72.6 years today.

The U.N. demographers calculate that the bulk of future population growth over the remainder of this century will be concentrated in sub-Saharan Africa, rising from just over 1 billion people today to nearly 3.8 billion by 2100. In contrast, populations in most of Asia, Europe, Latin America, and North America will peak and begin declining before the end of this century.

Africa will slow faster than the UN projects
Regional projections

Demographer Wolfgang Lutz and his colleagues at the International Institute of Applied Systems Analysis (IIASA) believe that the United Nations' projections are likely to be too high. In their 2018 demographic assessment, IIASA calculates a medium fertility scenario that would see world population peak at 9.8 billion people at around 2080 and fall to 9.5 billion by 2100. 

The IIASA researchers argue that the U.N. does not take adequate account of the effects on fertility of increased levels of education, especially the schooling of girls and women.

Alternatively, assuming rapid economic growth, technological advancement, and rising levels of educational attainment for both sexes—all factors that tend to lower fertility—Lutz and his colleagues project that world population will more likely peak at around 8.9 billion by 2060 and decline to 7.8 billion by the end of the twenty-first century. The global human population stands at about 7.7 billion now.

Other global trends, such as steeply falling child mortality rates, increased urbanization, rising incomes, and the spread of political and economic freedom all strongly correlate with families choosing to have fewer children. Instead of having many children in the hope that a few might survive, more parents around the world now aim at providing their children with the skills and social capital that will enable them to flourish in a modern economy.

The trend toward lower population growth is good news because it means that the global expansion of reproductive freedom is empowering more families to decide on how many children they wish to have.

NEXT: San Francisco Wants To Force CEOs To Pay for a Citywide Free Mental Health Care Program

Editor's Note: We invite comments and request that they be civil and on-topic. We do not moderate or assume any responsibility for comments, which are owned by the readers who post them. Comments do not represent the views of Reason.com or Reason Foundation. We reserve the right to delete any comment for any reason at any time. Report abuses.

  1. That means the mortality rate is probably going up, too.

    Blue Oyster Cult should update its lyrics.

    1. This ain’t the garden of Eden
      There ain’t no angels above
      And things ain’t like what they used to be
      And thus ain’t the summer of love
      Because now every day is summer
      Thanks to climate change

  2. About that purple line…

  3. Authoritarian Malthus worshippers hardest hit.

    1. +1

  4. The future will belong to those who show up for it. The aryans are gonna have a hard time with chart number 2.

    1. Don’t worry. White privilege will allow the last whitey to oppress the world.

    2. Come on now, don’t be a defeatist!

      The truth is if white people ever felt the need, we could effectively punk everybody else in the entire world even if we’re severely out numbered… We did it before, and we could do it again if the will were there.

      The Asians are the only ones we can’t punk. But we’re on pretty solid ground with Japan and Korea anyway, India is pretty down with the west too… So it’s mostly those sneaky Chinamen we gotta worry about!

  5. “The U.N. demographers calculate that the bulk of future population growth over the remainder of this century will be concentrated in sub-Saharan Africa, rising from just over 1 billion people today to nearly 3.8 billion by 2100.”

    Fantastic news! Just imagine how many of those people will want to immigrate to the United States.


    1. That’s #OpenBordersUberAlles

    2. We should take in AT LEAST 1 billion Africans! Imagine all the doctors and lawyers we can turn them into with our magic dirt!

  6. Even the new, lower projections are still implausibly high. Sub-Saharan Africa supporting 3.8 billion people? In what universe? That’s certainly not possible with the current state of institutions in the region.

    And if you could miraculously clean up all the graft, corruption and inefficiency of governments in that region, the very act of doing so would accelerate the limiting trends seen in other parts of the world.

    1. Even more critically, they might need a miracle to keep up with food and energy production–or some even more miraculous growth in manufacturing and services to trade for food.

    2. That’s the rub… They can’t even take care of themselves now.

      Without western aid, half of Africa would descend into civil war/chaos right now.

      The problem is that since the white people that prop them up are dying off… And they’re breeding like rabbits… At some point we’re going to reach a point where we can’t help them anymore. China seems willing to buy them off to a certain degree for their mineral wealth, but I don’t know how far that can go.

      In short, if Africa doesn’t at least get to South American levels of development… That shit is gonna completely fall apart at some point and there will be mass starvation.

  7. Meh. All the annoying young people will still want to live in the same few fashionable neighborhoods in the same mega-cities. And complain about high rents.

  8. But we’re all going to die in 10 years, so this is impossible.

  9. So I take it an apology from Paul Ehrlich is imminent?

    1. I think he is looking for his kudos…. If only the world had heeded his warnings sooner…..

  10. Overpopulation is one of the many bad things that liberals need to save us from. This will be repressed and ridiculed just like “Climate Change Denial.” And overpopulation is an important component of Climate Change, too many people using too many resources and overheating the planet.

    Liberals need for the world to be going to hell in a handbasket so they can justify their authoritarian policies that control every aspect of our lives.

    The World Will End in Ten Years™ if you don’t cede your rights to us!

  11. Well the Singularity is going to hit long before 2100, so all the graphs are irrelevant. We’ll just be uploaded into nanoscale memory sticks, if our AI robot overlords decide to keep us around.

    1. Time ends at 2038-01-19 03:14:07!

    2. That is in fact a real problem with a lot of these long term projections… They’ll be horribly wrong because of some of the “big” game changers that are realistic at some point. By 2100 I wouldn’t be surprised if we have super human AI. We could easily have genetically engineered people long before then.

      What would such changes do to population trends? Crazy shit, that’s what.

  12. Population peaking is not a “good thing” — every marginal added human, i.e. individual born, produces a net positive to the economy. The world is severely underpopulated.

    1. Not really.

      There are pros and cons to both… But a lot of it depends on who is being born.

      If everybody were a 180 IQ genius engineer/doctor/etc it could be pretty valuable… But with automation average IQ people are becoming next to useless already.

      Added population however DOES make resources more scarce per capita, and crams more people into less space, leaving less awesome land for people to occupy on a per capita basis, etc.

      So pros and cons.

  13. What are chances that, before 2100, people will be leaving Earth for colonies on the moon, Mars, the asteroid belt, and possibly much further away on generation ships?

    The population will already be declining by then (most likely) and we’ll have the added drain of folks leaving for greener (or redder) pastures.

  14. Ten billion by 2100?
    I’m not going to worry about it.
    There’s lot of space available in Antarctica.
    Besides, I’ll be dead by then.

  15. By 2100, who knows what shit will be going down.

    The problem will be in saaay 20-30 years. We likely won’t have any tech super powers quite yet, just incremental improvements of stuff we have now… But will have a shit ton more people to try to feed, and less work for average intelligence people to do… Leading to a lot of potential problems.

    As I have said in other threads on UBI, super intelligent AI, etc, it’s not the Star Trek future we have to worry about… It’s the decades in between now and the Star Trek future that will be crazy/fucked up as all hell.

Please to post comments

Comments are closed.