80+ Million Person Cities in 2100

By 2100, there should be two cities, Lagos and Kinshasa, with over 80 million people.

Lagos has an official government plan to support 40 million people by 2050.

The largest African, South Asian and Indian cities will pass Tokyo’s population by 2050.

China is integrating several multi-city regions into areas with over 100 million people.

The Guangdong–Hong Kong–Macao Greater Bay Area also referred to as the Greater Bay Area (GBA), is a megalopolis, consisting of nine cities and two special administrative regions in South China. It is envisioned as an integrated economic area aimed at taking a leading role globally by 2035.

It is the largest and most populated urban area and it is among the four largest bay areas in the world, comparable with the bay areas of New York City, Tokyo, and San Francisco. The GBA – with a total population of approximately 71.2 million people (5% of China’s total population) – includes nine mega cities of Guangdong province: Guangzhou, Shenzhen, Zhuhai, Foshan, Dongguan, Zhongshan, Jiangmen, Huizhou, and Zhaoqing as well as two special administrative regions, Hong Kong, and Macao (Macau). Hong Kong, Guangzhou, and Shenzhen have been described among the world’s 50 “superstar cities”.[3] Surrounding the Pearl River Delta with a total area of 56,000 km2 (corresponds to the area of Croatia), it is the largest and the richest economic region in South China.

GBA has a total population of approximately 86.17 million people (5% of China’s total population). The population is expected to reach 100 million people by 2030.

The greater Yangtze Delta zone has over 140 million people in this region. It is also being integrated. This multicity area includes Shanghai.

china’s Jing-Jin-Ji area has over 110 million people. This is the multicity area around Beijing.

23 thoughts on “80+ Million Person Cities in 2100”

  1. We are, each of us, the product of 3.7 billion years of mortal creatures that all managed to maintain a higher than replacement rate of reproduction. That’s going to take more than few generations of big city living to breed out of us.

    Less people, coupled with more automation, means more per person. That is where we are headed if global warming or some other existential crisis does not destroy us.

    People with more space, that are not significantly impacted in the pocketbook by having more kids, tend to have kids. The equilibrium level will come and it needn’t be dystopian at all.

    A century ago, someone at my level of relative affluence would have employed at least half a dozen full time servants (most of them supporting children of their own), including, if I still had small children myself, a nanny. Nowadays I would have to resort to getting a bi-weekly yard service rather than a gardener, a weekly maid service rather than a couple of maids, a smartphone in my pocket (and a dry cleaner on the corner) rather than a valet, a Grubhub account instead of a cook, an Uber app instead of a groomsman, and a stressful private kindergarten that costs enormous amounts in tuition and requires getting on “the list” even before the child is born.

    Digression. For those of you who think this is silly and, had you lived back then and had the means, you never would have employed so many servants, I will observe that, having lived some years in third world countries, Americans seem as quick to hire a full staff as a Victorian lord, when it is affordable and they can. Paraphrasing something I once read: “Most people, regardless of background, have no difficulty adapting to a society with an aristocracy . . . providing they can be the aristocrats.” Digression End.

    Servants probably aren’t coming back. But robots are coming. Oddly enough, rather than being a precursor to extinction (for whatever reason one chooses), they may significantly boost the birth rates among those who can afford them.

  2. Everything is about to change

    There is no point making this or any other prediction more than a couple of decades out. The singularity is clearly nearly upon us, and there is more chance that humans will be wiped out or scrabbling to survive as uncaring super intelligent AI takes control of the world. In no scenario is it likely that there will be high levels of employment needed to justify existence of job markets that make large cities useful. Deurbanization is a more likely trend.

  3. Chongqing is already over 30 million and it seems to work pretty well. I’d worry about quality of average person life in the future African and Indian mega cities.

  4. Seem to recall reading that, at one point, the Cape Buffalo covered the savannah in numbers uncountable. Then along came the rinderpest disease and, just two years later, it was very difficult to find even one.

  5. I can’t imagine us just descending in numbers until there is nothing left, simply through deciding to have less kids so we can have more fun. I also have to believe there is an equilibrium level.

    If I could be a radically life expanded fly on the wall, I’d like to see global population decrease to about one billion homo sapiens, but through gradual attrition and falling birth rates, not because of Putin or Thanos or any of those cartoonish villains with an oversimplied view of the universe.

    Of course, who could know how many machine-stored personalities might eventually be extant? There wouldn’t even be any real need for them to be on this planet

    • Just because you can’t imagine it doesn’t mean that it cannot or will not happen. The young see having kids as a bother. Who will decide to have them just because world population crosses some magic threshold? Won’t they prefer having a couple of dogs and travel the world instead?

      • Fortunately, not my young. We aren’t even religious, any of us, but we had another 4 grandkids added to the 3 already in the collective, just in the past year.

        We are all in the Greater New York metropolitan area or in the Los Angeles area, so aren’t exactly rural. They key denominator seems to be that the kids themselves have all pulled themselves up by their boot straps and become quite successful (all we did was ensure they were educated before they left the nest, it’s all my parents did for me and less than my wife’s parents did for her). They can afford to have children, even when it means one of them giving up a high remunerative career, at least for many years) and working from home or not at all. It’s probably no coincidence that their employers, although American, offer very generous, almost European-like, maternity leave and other benefits.

        Less people will drive up wages (if the Black Death is any indication) and thus, birthrates. Cognitive automation, which will also further fuel the still mushrooming industrial automation, will lower costs. Together, these things will increase supply and wealth per person, on average. The main concern I have is this is only the average. If we don’t deal well with how escalating levels of automation tend to increase wealth and income inequality, we could have a rough couple of generations. But that is a problem arising from circumstances that we can resolve by changing laws of humans, not laws of nature. This problem can be resolved by us, when the need drives sharply enough and, if it is not, it will destroy its own underpinning conditions–even if the latter would be the less preferable path.

  6. Big population centers, after Covid, scream huge probabilities of infectious health issues. Pollution, waste, garbage, rats…all concentrated. No thanks. Oh, and then there’s the issue that’s been on the back of my mind since before 9/11. If you want to do something stupid in the violent sense, a huge population center is the place to do it.

    • As we can see from the war in Ukraine big cities are very vulnerable to infrastructure … events. On the other hand, living in a huge metropoly might be the only viable option.

  7. Not impressed.
    Cities are a bit of an out-dated concept, since boundaries can be arbitrarily defined anywhere, are politically-driven, and instantaneous communication is ubiquitous. However, agglomeration economies are very complex ecosystems of labor, competition, co-habitation/ collaboration, and geographic density — vanguards of modernity and progress.
    Successful examples of high human density zones are increasingly rare due to ineffective transportation, hyper-inflated land prices, poor services’ maintenance and distribution, and spontaneous crime/ poverty cascades. The point is that an urban location’s success is more a function of the sophistication of the country -than- the ability to horde people together as quickly as possible. Which isn’t to say planned systems are better than organic systems.
    My guess is that G7 major urban areas are not growing as fast a they used to, likely plateauing to a certain critical size. More developing countries will increasingly learn that bigger is not always better. Zoning is a volatile concept though.
    I for one, think that housing, especially single-family, will not continue to grow as fast as population size, ex-urban areas with significant interstitial space will grow fastest, highways will flourish along with node transportation – commuter trains and smaller airports, and that personal movement and periodic re-location will increase — all harbingers of the slight de-urbanization of ‘rich country’ society – though not Detroit 90s style, of course. We will all look on to the African and Asian super-megalopolis’ with disdain and incredulity. Good luck with that, as they say.

    • I think planned towns/cities can still be a thing, as long as they are not too ‘Green-ed’ up – i.e. car intolerant, overly-themed on renewables rather than traditional power – just on principle, community/diversity before productivity/efficiency, etc. I’m surprised that there haven’t been a few more Billionaire-branded cities, especially around ‘their’ notable businesses – looking at you, Boca Chica, TX.

    • Cue -> Which are better? Chinese cities or American cities. Go.
      How to measure? Resident income levels? Crime levels per capita? Transit capacity per capita? I’ve seen Gross Metropolitan Product. Living costs vs national average…

    • “Successful examples of high human density zones are increasingly rare”

      By some very important measures, successful examples of high human density zones are non-existent.

      Historically, basically every city in existence has been a population sink, a place people went to do interesting and significant things while failing the basic biological test of actually reproducing. This hasn’t changed, if anything modern cities almost completely stop human reproduction. Moving to a modern city is almost as effective as getting surgically sterilized.

      This was acceptable so long as most of the human population didn’t live in cities. Life went on, the countryside made up the deficit, and the cities were doing useful things. Not a lot of reproduction happens in factories, after all, but they’re useful anyway.

      But developed nations have finally reached a level of urbanization where the cities are able to export anti-natal values to the countryside, resulting in a society-wide failure to reproduce, known as the “birth dearth”.

      Interestingly, not only are reproduction rates negatively correlated with population density, they’re also negatively correlated with a number of measures, such as wealth and crime rates, that would ordinarily count towards cities being considered successful. Wealthy, low crime cities are actually WORSE for human reproduction than dangerous slums are! This seems paradoxical, but actually makes sense from a socio-biological perspective: Perceived danger causes people to prioritize reproducing at an early age.

      This negative correlation between population density and reproduction rates isn’t confined to humans, by the way, it is consistent across a wide range of animal species. It seems to be a basic and highly conserved evolutionary adaptation, which we are unlikely to be able to easily circumvent.

      Here’s a fairly comprehensive study of these correlations, they’re very robust:


      How can a habitat for a species be considered successful if that species fails to reproduce in it? I think that’s a pretty important question, which should NOT be ignored. At least, not if we want to avoid extinction… Brian, you’re touting the latest in new and improved Human Roach Motels! Has that not occurred to you?

      • Very interesting perspective. Here in Canada we make up for a lack of fertility with mass immigration. But can a society who’s very existence depends on importing ever increasing numbers of people from less developed countries be considered a success? I would say no, since “advanced” Canada is by definition not sustainable without continuous external inputs of human capital.

        • Inputs of human capital, it should be pointed out, that come from the shrinking portion of the Earth where people still reproduce above replacement. What happens when the poorest places on Earth finally modernize?

          Can modern civilization be considered viable if it can only exist so long as a substantial fraction of the planet’s population aren’t yet modern? I don’t think so. I think we’ve stumbled into a societal dead end, that is kept afloat only because it hasn’t yet been universalized.

          • There is an equilibrium point. If we make an overly simplistic model, at some population density the human population stats having negative reproduction rates. As some lower densities the population still grows. If we have a continuous smooth curve there should be some equilibrium point where the birth rates are at replacement level. So we will never really run out of humans. However, there will be “peak human” and the replacement might be quite different from the original demographics.

            • I’m not a huge believer that maintaining or even improving human reproduction rates to way above replacement are an ‘absolute good’, at least in the near-term. The large numbers of low-value ‘additions’ to the population, epecially where services are scarce and adding significant skills/work ethic are rare. It is unfortunate to have to assess people as whether they are a ‘net benefit’ to society – at least within the working age population, but these are the ‘hard’ decisions and evaluations one may need to consider. I’m not sure that there is a politically-correct, vetted, Study of such things: say prison time, time without a high school education/verified skill set, use of government services, etc., as a quantifiable negative; and quality work hours, consumption, etc., as a quantifiable positive. From such, you would be able to discern a cut-off – of course, this would be unenforceable and likely unethical to establish ‘direct’ policy. But, as with periodic community surveys of family type to determine school funding, transit, etc., for a particular region, so must we direct resources to bigger ‘needs’ (and to establish one’s cost/benefit). If those targets are pro-family or pro-work or pro-education or pro-skills or pro-long-term-care-services, then the decisions would be that – though it is unlikely that such programs could mobilize quickly. Of course the private sector can act faster, if not predictably or without unforeseen consequences. Also, the idea of a population crash or mass skill shortage, beyond a simple annual or generational lull, is a bit hard to imagine – even if pandemic-related or large-scale disaster or simply localized to ‘disinterested’ richer countries over a few decades. I certainly buy into the idea that the more ‘broken’ countries appear to be getting larger faster while those countries who should be a services’ and technology role model are comparatively stagnating – though one may call this ‘healthy consolidation’.
              Ideal world population. Minimum average useful education/skill level. Appropriate family size. Minimum retirement benefits amount/ timing/ prerequisite… etc. All fraught questions with very ‘cultural’ answers. I do believe that increasing GDP is always good along with free-market and personal opportunity availability — though whether these are achieved by increasing good STEM skill sets and work ethic -or- by pursuing ‘rent-seeking’ and other opportunistic speculation will make the difference in system quality.

            • That’s actually part of what we’re seeing here: Basically all animal species instinctively regulate their numbers to avoid seriously overloading their habitat. Above some critical population density, they stop reproducing.

              Ordinarily this would be self regulating. Not smoothly, of course, but self-regulating.

              The problem we’re facing now is that areas where humans aren’t reproducing adopt anti-natal policies. If those policies were restricted to those areas, no big deal.

              But they’re not: Centralized government and democracy mean that, once high population density areas comprise a critical percentage of the population, they can impose their anti-natal policies on the areas that have lower population densities, and would reproduce if left to their selves. And those areas stop reproducing, too.

              Of course, eventually the population drops, and things return to normal. But in the mean while you can get some pretty radical distortions of age demographics, that are economically unsupportable, when the last generation produced reach old age, and few children are around to support them.

              We’re already headed towards that fate, we better hope that automation solves the problem.

              • @Brett Bellmore
                We have two possible dystopian scenarios. One is we run out of people. The other says the automation/AI will make people obsolete. And those options are not exactly mutually exclusive. It is a wide spectrum. For now the meatbags are useful. But with an advanced AIs the temptation to cull the “inferior/unwashed” masses becomes stronger. It could be soft like letting poor uneducated people sink into virtual reality. The problem is human usefulness/capabilities can easily be ordered along a power law. Probably the top 10% are as “useful” as the bottom 90%. However the same applies to the top 10%. Top %1 is superior to the bottom 99 and so on. And when the AI is better than the best 0.01% “we” don’t need meatbags at all.

          • Maybe this theory of yours explains the Fermi Paradox: could all these ancient alien societies have gotten so developed that they stopped reproducing and therefore became extinguished?

      • This is turning out to be the biggest anti-city argument ever. Because I can’t see any counter-example that doesn’t involve a lot of immigration of people from the poorer rural regions, turned in merely a generation into the same ageing, sterile population.

        If cities are inimical to human reproduction, then they are doomed long term. Or we’ll be. Same as any future dreams of space colonies, which are like hyper-expensive cities.

        But are the cities the problem, or just part or it? is it something else?

        Seems to me the city-dweller mindset of “enjoying yourself”, “live and let live” without any of the burdens of life might be the problem. It’s simply unrealistic, disconnected from the blunt realities of being fragile, quickly ageing living beings that need to replace their numbers or disappear.

        Are we doomed to be agrarian peasants that toil endlessly with a low sophistication culture, in order to not cease having the will to live?

        It might happen that the way is forward: ensure the city dwellers live longer to not need so many new people, and have machine-provided assistance. That seems to be our current bet, without clear odds of winning it.

        • Clearly “enjoying yourself” is an expression of an individual’s will to live. That hasn’t ceased. What is declining, is the affordability of reproduction. One average income used to support a whole family, now two barely get by. Why would anyone, average or below, choose to put themselves in that situation? Self preservation instinct is about the self, after all. It comes before almost every other instinct.

          Cities aren’t the issue, low wages are. Old-school (Victorian and prior) wage slavery existed in a system where you could send your children to work, so actually incentivised having more. That isn’t the case now, for better or worse, so a comparison can’t be directly made to the olden times. If you want people to have more children, set the minimum wage to a level where people can actually afford to have them, without having to work 40+ hours a week.

          • The problem is, that raising kids is much more expensive in time and effort in a modern civilization than in the past, in an irreducible way. A more complex world requires a much longer education and formation period.

            Merely reducing the cost of rent, food and others will not make people more willing to have kids, because educating and caring them to be viable modern persons isn’t just monetarily expensive, but humanly and emotionally taxing too. At most, people will want the experience with one kid tops and be done with it. And that still is a population collapse.

            We have been engineered to want the best of life, freedom of expression and from remove bad life experiences; and taking care of several babies, while cute and fulfilling, goes against that for most people.

            Besides, the pessimism and cynicism about the world, unrelated to one’s actual life conditions, have never been higher. Being over-informed and over-stimulated with the bad outcomes of anything might be related to that, but it’s a fact people without hope (with or without bad experiences) tend not to take risks like bringing more people into the world. My point is, the human infosphere itself might have become a toxic hazard for our species.

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