J.D. Moyer

sci-fi writer, beat maker, self-experimenter

How It Might Go Down (A Global Population Scenario)

Up and up and … ?

A graph like the one above should make you nervous.  A line going nearly straight up indicates a “bubble” situation — and all bubbles must pop.  Dot-com bubble, U.S. housing market bubble, Dutch tulip bulb bubble; historically, there are dozens of examples of market bubbles.  The above graph references population, not markets, but there are just as many examples of animal population crashes (for example the chilling story of the reindeer of St. Matthew Island in Alaska).  Bubble dynamics are always the same; exponential growth is never sustainable, and is thus followed by exponential shrinkage.

Human population can’t go up indefinitely.  Something will eventually limit (and reverse) our growth.  It might be food, it might be energy, or it might be cultural factors.  “Doomers” predict human population decline will be brought on by hard limits to oil and food production, and will be accompanied by chaos, violence, and strife (Thomas Malthus, with his predictions of overpopulation and mass starvation, could be considered the original doomer).

Some, like the environmental writer Fred Pearce, predict a rosier decline.  Pearce predicts that voluntary reduced fertility (women choosing to use birth control) will allow human population growth to taper off and eventually decline gradually, with a a minimum of strife.  We’ll avert economic catastrophe by working into old age; we’ll “harness older people as a resource.”

My bullshit detector goes off listening to both lines of thinking.  The doomers and the optimists are both overlooking important variables.  To get a complete picture of human population decline scenarios, what factors do we need to consider?

An overpopulated Coldplay concert.

Why So Many?

Why are there so many of us?

The short answer is that we invented artificial fertilizer before we invented birth control.

Fritz Haber.

Historically, our ability to produce food, as a species, was tightly controlled by the availability of natural fertilizer (animal poop, food scraps, etc.).  With the invention of the Haber-Bosch process, we could suddenly create ammonia-based nitrogen fertilizer out of thin air (by combining hydrogen, from natural gas or coal, with nitrogen, from air).  As you can see in the graph above, human population was already rising quickly in the 1800’s.  But when the Haber process became widespread, in the early 1900’s, we really took off.  Eat, breed, eat some more!

The thing is, most human beings don’t actually want to have a large number of children.  What we want to do is have sex (evolution made sure of that).  Evolution also made sure that most of us look after our kids to some extent — we very much want to see them well-fed, healthy, and surviving into adulthood.  But if we’re given a choice to have sex without having children, we’ll often go that route.  Raising children is difficult and expensive.  People who don’t know that quickly learn it as soon as they have their first child.  My point is that there is no natural impulse to radically overpopulate the planet with human beings.

Unfortunately, we didn’t figure out a way to reliably have sex without have children until the 1960’s.  The Pill changed everything.  Women could now control the fertility process (men are less motivated to responsibly use birth control, because the burdens of pregnancy and infant care fall primarily on women).

Women, when they have access to birth control and access to healthcare for their existing children, universally choose to have fewer children.  As the availability of birth control, decent health care, and women’s literacy spread in developing countries, fertility rates are rapidly dropping.  In most developed countries, fertility rates hover around replacement level, or lower.

Modern agriculture, culminating in the Haber process (and later, genetically modified high-yield crops), removed a hard limit to population growth that had existed for centuries.  This allowed human population to explode.  Still, we are thinking animals, and we’ll make reasonable procreation choices if given the option.  What if oral contraception had preceded Haber-Bosch by a few decades, instead of vice versa?  If oral contraception had been invented in 1910, and the Haber process in 1960, global population would currently be under 3 billion, and already starting to drop.

Chernobyl. Energy production is costly and dangerous business.

Three Variables

The three most important variables for how human population will decrease (gradually and peacefully or rapidly and violently) are food reform, cheap energy, and global women’s rights.

Important non-variables are climate change (it’s happening, and will be accompanied by floods, droughts, and major local food production disruptions), and culture bleed (increased inability for an isolated culture to remain isolated, due to internet/global media penetration).

If we zoom ahead thirty years, to 2041, we’ll most likely have clear answers to the following questions:

1) Have global food production techniques been reformed?  This would include:

  • sensible ocean management (large protected areas, protected reefs, prohibition of destructive fishing techniques)
  • widespread ultramodern polyculture farming (hyper-efficient land use, less reliance on chemical fertilizers and pesticides, tree planting to protect topsoil from wind and flooding)
  • decentralized food production (greater number of smaller farms, more local production, lower shipping/transport costs)

2) Do we have reliable sources of cheap, clean energy? These could include:

  • ultra-efficient solar cells, large solar energy plants
  • cold-fusion (probably not, but who knows?)
  • clean, safe nuclear (not popular right now because of Japan, but if the Chinese can get pebble-bed reactors to work, it would be much safer than coal mining)
  • modern grids that facilitate low-loss energy transport, electric vehicle charging, etc.
  • widespread home energy production, totally decentralized energy production (throw your plastic trash into home “electricity maker”)
  • other renewable sources (wind + compressed air, hydro, geothermal, etc.)

3) Do the vast majority of women in the world have equal rights?  This would include:

  • access to education
  • access to birth control and quality health care (for self and children)
  • voting rights
  • right to work, equal pay for equal work

In short, the closer we are to three no’s, the more likely the doomers are right.  Global population may keep rising quickly and then crash hard and fast, accompanied by war, starvation, and disease.

If we can answer yes to all three questions, then Fred Pearce’s vision may be closer to the truth.  Global population growth will taper off gradually, and then decline gradually and peacefully.

Peak oil manifesto.

Other Factors

In addition to these three variables, there are some black swan type events that could wipe out human population, including:

  1. Giant meteor strike that globally blocks sunlight for several years
  2. Supervolcano eruption that globally blocks sunlight for several years
  3. Major nuclear war; fires that globally block sunlight for several years.
  4. Engineered virus for which none of us have any resistance.

There are many other possible calamities, but I don’t see natural viruses, climate catastrophe, economic collapse, world wars, or robot uprisings taking out more than a few million of us at a time (excepting a robot uprising, we’ve been through them all, and there still are close to 7 billion of us).  To get into multi-billion level casualties, you need to cut off human beings from the sun, or engineer something incredibly nasty on a biological level.

There are also other factors that will definitely slow down or provide a boost to human population growth, but to a lesser degree than the big three or a black swan event, including:

  1. The spread of secularism, or religiosity (see my previous post).
  2. The spread or regulation of endocrine-disrupting chemicals that significantly and negatively affect fertility (like bisphenol-A).
  3. Civic policies relating to healthcare and child care (universal healthcare, public preschool, and mandatory maternity and paternity leave all encourage higher birth rates).

United Nations population graph, showing future population projections at various fertility rates.

2041, The Most Likely Scenario

Here’s my prediction.

In 2041, we will not have a cheap source of energy; energy will be more expensive than it is now (by 100% or more).  However, energy production will be more diverse and less centralized.  Some countries will have extremely efficient, clean energy systems.  Other countries will still be digging up coal and burning it.  Oil will still be our primary energy source, but it will be much harder to extract, and much more expensive.

Food production, for the most part, will not be reformed (or reform will be too late).  The oceans will be mostly depleted (though some areas will be protected and recovering).  The fish we eat will be mostly farmed.  Food production will only be 15% reformed to modern polyculture, primarily to produce high quality food for the rich, but also some pockets where poorer countries have aggressively promoted agricultural reform.  We’ll lose massive amounts of food to flooding, drought, and crop disease from global climate change.  Fertilizer and food will generally be more expensive (by 100% or more).

Global literacy, education, and access to birth control will continue to rise, and fertility rates in developing countries will continue to plummet.  Isolated cultures and countries will be unable to resist the pervasive, virus-like spread of modern Western values via mobile internet devices.  Though this may have many noxious effects (spread of shallow pop culture and consumerism), it will also result in more equal rights for women, access to free education (like Khan Academy), and many other positive effects.

Global population will peak at 9 billion in 2060, somewhere in between the low and medium U.N. projections (see graph above).  Population decline will be due primarily to couples choosing to have fewer children (high cost of living + availability of birth control).

Higher cost of living will result in more small-scale wars (most battles over food and energy resources), and more revolutions.  The most stable government configurations will be those that manage to keep their poorest people well fed and adequately housed.  Governments that fail to do this will experience massive protests, revolutions, and military coups.

Population change will be experienced most acutely on the municipal and national levels.  Societal collapse due to depopulation will be more common than societal collapse due to overpopulation.  The collapse of the Soviet Union can be interpreted as a depopulation event.  Russia, Japan, Italy, and other countries with low birth rates will need to reverse (via increased immigration and birth incentives) or manage their population decline, or risk collapse.  Some cities, like Detroit, may entirely depopulate if they don’t manage their decline (perhaps via aggressive rewilding), or provide massive incentives to attract new residents (like giving away land and houses, along with multi-year property tax waivers).

In other parts of the world, massive overpopulation combined with high food and energy prices could lead to malnutrition and stunting, greater incidence of disease, violent revolutions, tribalism, criminal gang wars, and all manner of ugliness.  China and India will continue to be the most populous countries, with most of the world’s poor, and civic policies in these countries will influence billions of lives.  Choices related to food production, energy production, and social welfare will stave off suffering in some populous countries, and invite it in others.

Worldwide, higher energy and food prices will stagnate the global economy.  The poor and remaining middle class will consume fewer goods and services because more of their income will go to food and energy.  Governments that support the poor and middle class with progressive taxation (taxing the rich, who don’t spend their money anyway), and providing quality public services (healthcare, education, and infrastructure) will fare better, and be less vulnerable to revolution.

A major depopulating black swan event will occur sometime before the sun explodes, but human population will have already peaked before then.

Population will peak well before we migrate into space (terraform Mars, or even have a constantly inhabited, self-sustainable moon base).

It Could Be Worse

Is it time to start hoarding ammunition and tins of sardines?  For most people, probably not.  However, the most likely scenario does point to a few decades of much higher energy and food prices, along with general economic stagnation.

Successful food reform or cheap energy could change things dramatically.  The world’s poor would be much better off, and so would the global economy.  All of us would have more money to purchase goods and services if we had to spend less on food and energy.

Fortunately, birth control and family planning will ultimately save us from a massive human die-off.  We’re already slamming on the brakes, voluntarily, well before we starve to death like the reindeer of St. Matthew Island.

Eat and breed until the food is gone, then die.

2100 and Beyond

Once we’re on the downslope, the major problems we’ll be facing as a species will be global economic stagnation, and municipal depopulation.

Eventually human population will decline, and renewable energy will advance, to a point where food and energy once again become cheap.  This will provide a boost to the global economy, freeing up massive amounts of wealth to purchase goods and services.  Until then, nations that want to thrive will need to do whatever they can to avoid rapid depopulation, support the middle class and lift up the poor (thus freeing up money to buy goods and services and support the economy), maintain public trust, and generally encourage economic activity.

Cities will need to voluntarily shrink, rewilding large portions or converting abandoned lots to food or energy production.  As we’re currently seeing in Detroit, this kind of process requires vast amounts of political will and community organizing, and is difficult.  Some cities may simply decay to the point of total abandonment, to be reclaimed by the elements within a few decades.  This is already happening to many houses in Detroit.

Until energy and food production are once again growing faster than demand, we’ll experience a new Dark Age.  What the doomers don’t realize is that this age has already begun.  Look at the headlines.  Oil and mineral wars, revolutions, stingy spending on “non-essentials” like culture and science — we’re already in it!  Peak oil already happened.  For most of the developed world, the “ticking time bomb” of global overpopulation will explode slowly, over a 100 year period that we’re already well into.  It won’t mean guns and canned food, but it will mean shorter vacations, higher unemployment, choosing to have fewer children, and more vacant lots.

Feral house in Detroit.

When Will The Next Golden Age Begin?

I hope this post hasn’t left you feeling pessimistic.  I actually feel more upbeat about the future than I did before I started researching and thinking about this topic.  Our current Dark Age won’t be nearly as bad as the original Dark Ages.  Some of us will die prematurely from oil wars, lack of healthcare, or working three jobs, but most of us will muddle along as usual, with our tight budgets and zero to two children.  The wise will be just as happy as ever, deriving pleasure from family, friends, food, sex, nature, spiritual or religious practice, novels, music, film, sports, and other low-cost human pursuits.

Fun times ahead! (if we can just get through this 100 year dark age)

When the energy production curve once again overtakes the energy demand curve (perhaps sooner, due to massive innovation, or perhaps later, due to less innovation and decreased population), human beings will start getting interesting again.  We might start to take on some huge, expensive projects, like creating a space elevator, interstellar starships, or virtual worlds indistinguishable from reality (holodeck!).

It’s even possible that a new Golden Age could be triggered before energy production catches up with demand.  While the internet is mostly used for porn and looking at funny cat pictures, it also happens to be a fantastic medium for idea sharing, knowledge acquisition, and active (if rarely civil) political and philosophical dialogue.  I can’t rule out the possibility that the internet will trigger (or has already triggered) a second Enlightenment.

Modern civilization might collapse entirely, but I’m optimistic that once we’re “over the hump” (of population peak), we have some excellent times ahead.


Michio Kaku Should Stick to Physics (Evolution, Birth Control, and Mate Selection)


Sick (Thoughts on Various Cold and Flu Remedies)


  1. Nice job J.D.

    This is a really important topic that more people need to understand, in fact I think it is critical that they understand it.

    I spend a lot of time thinking about my future… I don’t know if I should pursue a professional career in the kinesiology and nutrition field, or should I move back to Alaska, away from large amounts of people, where we have a self-sustaining homestead and can collect our own water, raise are own crops and animals, hunt on our land, and heat ourselves with wood?

    I know that either path would be enjoyable and fulfilling for me, which just makes it harder to decide. Maybe both?

    If we’re lucky we can fix these problems before they get out of hand, but I am not particularly optimistic considering our current tendencies.

    Instead of complaining how the last several generations screwed us over, my generation needs to take some initiative and get in to fixing this. There’s not really anything more important.

    People need to be educated and we need to innovate. I have hope that the internet will allow us to work together to make some leaps in technology.

  2. Thanks Tyler. One thing both your generation and my generation can thank the Boomers for is making birth control wildly popular. Without the “free love” movement of the 60’s, the world might have 12 billion people. 😉

    I hear you though — your generation will have a tougher time economically than the Boomers or even Gen X (my generation — we benefited from the dot-com boom at least). But ultimately most of you will do fine — you’re a smart and capable bunch.

  3. Haha, a smart and capable bunch? I hope so. The attitude I see in most of the students in college right now, especially the younger ones is kind of scary.

    Nearly complete indifference to what’s going on in the world… If it does not effect them right now, it’s not important enough for them to worry about, they would rather play with their iphones… maybe it is just a stage they are going through, I could be hypersensitive to noticing it.

    The activity of young people in the middle east is very encouraging though… they are really making things happen.

    My main worry is that we will do something that has a permanent or very long term effect on the earth and has far reaching consequences… for example, somehow severely disturbing something low down on the food chain that sets off a cascade of effects that results in completely unpredictable changes up the food chain.

    Or BPA (or something similar) building up in the environment to toxic levels. BPA is nasty stuff… I have it in two dental sealants and I’m not happy about… nothing I can do to get rid of it either.

  4. Madelyn

    What a great article. This is something I think about A LOT. I do have some hope attached to the current gardening movement in the US. I went a an OSU gardening class on Thursday. I learned that urban farming is becoming popular so fast that there are now runs on seeds. If you don’t get to the seed catalogue early, you might not grow those tomatoes. I’m further encouraged to see composters at Costco and hear of Walmart’s recent vow to source local food products in their stores. (Though I do have healthy doubt about their commitment, time will tell.). I am also heartened to hear that law makers in Oregon may give tax incentives to homeowners who convert sod to food production, and further deductions for donating some of that food to food banks. This is innovative, smart, and inspired/inspiring. I realize that each of these are small things, but incremental change can effect a big difference in trajectory.

    It’s sad to learn of the apathy Tyler sees in his peers. The millennials, as they’ve been called, haven’t had to live through the tough times other generations, including X has. Gen X lived through the recession in the 70s and may even remember long lines for gas. Mill’s have had a life of consistent plenty, coupled with Baby Boomer parents who’ve told them that they are special. (This is from a CBC broadcast on the different generations represented in the current workforce, not my own observations or assertions.). It will be interesting to see how they “grow up” with this recession, and the new Dark Age, as you call it.

    Even here I am hopeful. Tyler’s not alone in his desire to go back to the quiet life. In fact, this is the first time in decades that the number of farms and farmers is on the rise. There are like-minded people. But yes, you have to wade through a sea of iPhones to find them.

    On a personal note: yeah for birth control! I can’t imagine giving birth tomsome of the kids I might have conceived with past partners. I’m glad to see the global trend of access to family planning for woman. We love our babies, but the choice not to have them is a blessing that should be considered a right.

    Good work Jondi. Thank you for a well written and thought provoking piece.

  5. Hi Madelyn! Glad you enjoyed the post. Runs on seeds — I had no idea. It makes sense though. DIY farming and food is THE thing these days (not complaining — it means I eat well).

    Here’s a great article on global family planning:

  6. Thiago

    J.D. Moyer, that’s a very bleak future you’ve described there. I see it differently.

    I think that human intelligence can take a large leap with the introduction of brain micro-chip implants which will allow us to download information into our brains. We could possibly learn advanced maths, languages and other subjects in seconds.

    This will eventually allow us to experience higher dimensions and reprogram our universe or surroundings. We could even project ourselves into a virtual simulation of reality. There are also other possibilities such as space travel and quantum teleportation. Quantum teleportation would mean that the population could grow, as food would be transported at lightning speeds as well as people. This would also eliminate the need for oil.

    Space travel could be accomplished, as the whole human race would have an understanding of advanced physics, electronics and engineering through the information that could be downloaded into our brains.

    If you think that this sounds impossible, then you have to take a look at the bionic eyes that are already being implanted into humans, plus you should also take into account bionic arms and legs that are slowly being introduced.
    There hasn’t been a revolution in this early century, but there has always been an invention that completely changes the world every 50 years since the 1800’s.

    There are so many possibilities though, and it’s difficult to determine which way our future is going to go. Who knows, we might be living in a parallel universe and what we believe will be the case.

  7. Hey Thiago — I hope you’re right. What you’ve outlined is the classic transhumanist position. I think you’re wildly optimistic, but there are plenty of peak oil/doomsayer types who think *I’m* wildly optimistic. Let’s hope technological, cultural, and spiritual progress can outpace human folly, greed, and resource depletion.

  8. Thiago

    Look how much humans are learning in a space of a day. In 12 hours we can study a whole range of topics, from medicine to physics thanks to the internet. Only 20 years ago or less, to accomplish this feat, we would need to travel to libraries and search vigorously for the information that we wanted to find. It would have taken probably 12 days to get hold of the information I now have in 12 hours. Maybe even more.

    How about things that were physical? Goods such as watches, calculators, notebooks and pens. They’ve all been sucked into the digital world. A watch a hundred years ago cost how much? Now I have one everywhere, for free.

  9. The U.N. has recently raised its end-of-century forecast to 10B.


  10. hahahahahahaa

    hahahaha that was really funny lol i now understand the world better

  11. Lauren

    i loved it lol

  12. When I saw originally this population graph, it was on the peal oil Michael C. Ruppert documentary collapse I though of a good ole song that has always proven so true over the years and it goes a little like this…. “What goes up … must come down”….

  13. I’ve just spent the last 6 hours reading your blog J.D (found it looking for GH maximizers). This is one of my favorite posts. I dont have anything meaningful to contribute to this conversation yet, but I wanted to chime in and let you know that your work is excellent and worth the time you spend on it.

  14. World Population Growth — great graphs! Rate of growth dropping since sixties.


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