I've got whiplash from the speed at which we've jumped from overpopulation doomsday to demographic degrowth doomsday.<p>It seems likely we lend too much credence to experts ability to model complex systems over a long period of time.
That's the thing with exponentials, they are very hard to predict. We know that in general, exponential growth is unsustainable, and there has to be an inflection point, but where? It is usually difficult to know until the last moment, and even a small difference in time on where you predict the inflection point is can make a massive difference.<p>Look at COVID for instance, not the first novel coronavirus infection, it only took days to go from "maybe it is like the other ones that infected a few thousand people" to "everyone on the planet will get it", because the start of the curve looks the same.
You got whiplash over the speed of...a few decades? Malthusian theory had been proven wrong and people have known this since last century.
The population hysteria from the 60s was proven wrong a long time ago but it's still pretty influential. E.g. it's not uncommon for millenials to talk about not wanting children because of overpopulation.<p>It takes a long, long time for new ideas to diffuse through society. Most people are not paying close attention to the cutting edge.
> The population hysteria from the 60s was proven wrong a long time ago but it's still pretty influential<p>I wonder if people in the 2080s will say that about the underpopulation hysteria from the 2020s.
The next 50 years will cause all industrial countries to face an irregular demographic profile, weighted toward the elderly. The median age in China is almost 41, while the US is reaching 39. In the US, the elderly (65+) will be almost 1 in 4 of the population ~2050. In contrast, boomers were 37% of the US population at their height (elderly were ~9.5%).<p>There is no underpopulation hysteria.
However, the math around demographics is settled.
Even if there's a lot of scientific evidence, statistical proof etc. it's sort of surprising to me that when chatting with people all over the world (in dense cities and also in non-dense areas) how often I hear the sentiment that "there are too many people" and get the sense that they do mean that there's too many people in the world (not just within the surrounding 5-10km which might actually be true).<p>This might also be one of those things that aligns with people's experience of the world, and the de-population thing is inherently counterintuitive unless you are, by definition, outside the norm- that is, you would only ever notice this if you live where people already don't live. (rural Japan, etc.)
I think for most millenials it's an excuse not really the actual reason they don't want/get kids (although i think there's a few actual believers).
Millenials talk about not wanting children because they don't want to subject a new generation to this absolute shitshow of a planet, or because they can't afford the time and resources to adequately raise them.<p>I've not heard anyone talk about an overpopulation problem in 30 years.
I'm a millennial and I really really like this planet. It's my favorite one. My kids are going to like it here too someday, I hope.<p>My peers who are skipping kids are mostly doing so because their other ambitions don't align with raising a family, which I totally get. It's a huge trade off, I hope it'll be worth it.
>doing so because their other ambitions don't align with raising a family,<p>Are your peers more ambitious than mine or are their ambitions to travel for cheap and watch as much netflix as possible?<p>(This is obviously not true of my coworkers/friends from work who can all afford kids and most choose to)
"They had such <i>enormous</i> fun that they called for another elephant to come."
gen x here, and my observation is that millenials tend to let there back brain say whatever the 'expected' response is,as having had it barked at them from birth makes it effortless, and then going back to bieng cagey,mildly subversive, and somewhat ferral in there actual lives.
point of order : there is NO trade off in getting what you want.
As a general rule they won't talk about overpopulation being a problem because they know that the population will likely peak within their children's lifetimes.<p>They do talk about whether the earth can sustain that population as a reason not to have children. They are correct to. Their children might be the generation who have to explain to <i>their</i> children what fish tasted like.
yes, this is the thing I'm not quite getting from the "malthus was proven wrong" argument. Yes, technology increased food production, but that doesn't mean there isn't a carrying capacity to the earth. We have overfished. Fisheries are in decline all over. I guess you could say "no problem, we'll have lab created or grown fish and it will be fine" ok, maybe. But it's not going to be the same and the oceans won't be the same.<p>What I don't get from all of the demographic collapse hand-wringing: Somehow in the 1970s we got by with 1/2 as many people as we have now - why would a long, slow decline back down to that number be catastrophic? Why would stabilizing at a lower population be problematic? Sure, during that decline there's going to be issues, but once you hit a new stable population those would go away.
The issues might go away sooner than that, because I imagine - naively? - that a society full of old people would put lots of effort into reducing the problems of being old.<p>Having declined, the population might increase again, and decline again, but with fewer issues the more practice we have. Stability sounds unlikely.
> > Somehow in the 1970s we got by with 1/2 as many people as we have now - why would a long, slow decline back down to that number be catastrophic?<p>Because we've built an economic system based on the idea that you must, at all costs, grow. Stable success is insufficient and will be seen as failure.<p>And then we spent many decades programming people to believe this is the only thing that can possible work.<p>Nothing natural about this at all, it is just the result of the cult of capitalism.
Have we, though? Governments rely on <i>economic</i> growth to fund their plans. That means <i>economic activity</i> has to grow, which means ... something ultimately rather unclear about what people around at the time consider wealth to be. It doesn't mean "everybody into the spawning pools and get busy".
> Millenials talk about not wanting children because they don't want to subject a new generation to this absolute shitshow of a planet<p>They often list overpopulation as a reason. But yes, it's not the only reason they give.<p>As an antidote to this kind of mindless negativity, just consider whether any individual human is happy to have been born. It seems very clear to me that most people enjoy being alive and so having children is moral on utilitarian grounds.
> Malthusian theory had been proven wrong<p>It was never proven wrong, as much as the world changed in a way that invalidated it.<p>The entire idea was that population growth was an exponential function, whereas agriculture output was a linear function. There would have been famine if nothing had changed, because there is only a certain amount of physical labor a person is capable of doing, which has to be divided between the farming, logistics, and cooking of the food.<p>What happened was that a century later we got mechanized farming and synthetic fertilizer, decoupling agricultural output from the population. Now a single person can do the work of thousands, and every year that number grows due to technology advances. It is too expensive to set up fully automated farms on the industrial scale, but it is technologically possible.<p>But none of that invalidates his idea. If you believe that an exponential function and linear function sharing a point at (0,0) must cross each other (subject to other reasonable conditions like not having crossed yet, the linear having a positive finite slope, etc), then it is not logical to reject Malthus. It just no longer applies because we decoupled our food production capacity from the population size.
You also have to believe that population growth is fully exponential. But in practice it looks more like a logistic curve, and the factors that slow it down are a lot less dramatic than resource starvation or violence.
As long as I keep hearing about the need for reducing meat consumption and supply chain slack (food waste), I'm inclined to think Malthus was right despite the limit turning out to be soil capacity rather than labour capacity.
I mean insofar as the idea is about contemplating those mechanisms in the abstract, sure. But insofar as they were predictive or an attempt at a descriptive characterization of where populations would actually go, clearly it didn't hold. And if it didn't hold because it's true on it's own terms in some abstract sense, so much the worse for its inability to model changes that would prove to be relevant to actual population dynamics.<p>It's also not just that we accommodated explosive populations but that eventually birth rates really did simply start slowing down for discernible reasons that future models were capable of integrating. Even if we continue to have technology that would give us the capacity to accommodate future increases in population, those increases are no longer happening.
I mean, by proven wrong that's what I mean. I'm not talking about the theoretical mathematics but the real world application of theory in which case, yes, Malthus was proven wrong.
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Well I wouldn't both-sides this one. 2020s population forecasting is better than 1960s forecasting, the latter was repudiated and the former is correctly modeling basically everything. Demographic decline really is happening and has reasonably well understood mechanisms.<p>I suppose I would separate out some of the more extreme predictions about demographic collapse in Russia or China. I'm not sure what to make of those or if they're similarly credible to other kinds of population forecasts.
I think it's the 'doomsday' part that's the problem. Not everything is the 'end of humanity'.
>It seems likely we lend too much credence to experts ability to model complex systems over a long period of time.<p>I swear, half the problems in this world are humanities people doing linear progressions and advising somebody making a policy based on that.
It takes an uncommon breadth of perspective and depth of intellectual humility to contradict evidence it is your job to collect and interpret.<p>Sometimes the trends of tomorrow just aren't in the data of today.<p>What modeler in the late 19th century, when children were still economic assets on farms and in factories, could have predicted they would become extraordinary economic liabilities?
Assume neither are true and they are both based on faulty models of reality<p>Think about it this way: the desired population is a sub-function of the desired society that someone is attempting to describe<p>If the total population configuration is growing faster than your desired population configuration then simultaneously:<p>1. There’s “too many” people not like me<p>2. Not enough people like me<p>Every argument about this is pure chauvinism
Only people who hate immigration think there is under population.<p>My country GDP growth has been dependent on foreigners since time immemorial.
I think a lot of the difference is due to different groups/lead figures/experts focusing on different concerns, e.g. people like Paul Ehrlich and environmental groups focused on ecological sustainability vs people like Elon Musk and governments focused on economic sustainability
> It seems likely we lend too much credence to experts ability to model complex systems over a long period of time.<p>You say "complex systems" but are actually referring to human behavior.<p>Humans are unique in that they change their behavior in light of predictions. You can't make a prediction, and publicize that prediction, without changing the system.<p>From what I've heard, many people are declining to have children precisely because of the environmental effects of overpopulation. There are of course other factors, but that's one factor.
It’s more that we constantly extrapolate what experts are doing to the real world without taking in account the actual details. A research team comes up with a model that has some specific biases, parameters, etc. it yields some results. The result is then taken completely out of context and applied to a messy dynamic real world situation we don’t even have reliable metrics for. Then it just becomes a fight over narratives
Fear mongering / doomsaying has been a popular human tendency for as long as we have been able to record our interactions.<p>If you’re vague enough about it, you can never be wrong! And if you’re overly specific and have a modest following of rubes with more money than sense, you can take some of it! A lot of it!!
Exactly!! During my childhood I used to be terrified if population explosion<p>Now that I have a kid, there is doom over population shrinkage<p>Sadly this will be used by propagandaists to doubt scientists
This scares me to be honest. We have an exponentially decaying graph if we compare resources on y v/s consumption on x. I don't know what the next 50 years are going to bring considering the total resources to use on Earth are an "infinite constant".
Sounds like we could use a psychohistory expert.
<i>the planet will be devoid of people on Tuesday, 5 May 3108</i><p>Der letzte macht das Licht aus.
"The great vice of the Greeks was not sodomy, but extrapolation"
The article assumes the original 1960 paper by von Foerster was a serious prediction. It wasn't. It was a joking example showing that fitting hyperbolic growth models do data leads to an absurd singularity, an infinite population in finite time. A much better write-up on it is Scott Alexander's "1960: The Year The Singularity Was Cancelled": <a href="https://slatestarcodex.com/2019/04/22/1960-the-year-the-singularity-was-cancelled/" rel="nofollow">https://slatestarcodex.com/2019/04/22/1960-the-year-the-sing...</a><p>Scott's conclusion (written in 2019, a year before GPT-3 was published) is perhaps more interesting today than it was then:<p>> In other words, the singularity got cancelled because we no longer have a surefire way to convert money into researchers. The old way was more money = more food = more population = more researchers. The new way is just more money = send more people to college, and screw all that.<p>> But AI potentially offers a way to convert money into researchers. Money = build more AIs = more research.<p>> If this were true, then once AI comes around – even if it isn’t much smarter than humans – then as long as the computational power you can invest into researching a given field increases with the amount of money you have, hyperbolic growth is back on. Faster growth rates means more money means more AIs researching new technology means even faster growth rates, and so on to infinity.<p>> Presumably you would eventually hit some other bottleneck, but things could get very strange before that happens.
Great link, thanks. In a pretty remarkable coincidence the post you linked, which itself is from seven years ago, considers a prediction from over 60 years ago of an anticipated doomsday, and that doomsday date just so happens to be a few weeks from today:<p>>In the 1950s, an Austrian scientist discovered a series of equations that he claimed could model history. They matched past data with startling accuracy. But when extended into the future, they predicted the world would end on November 13, 2026.<p>Set your calendars!
What's the coincidence? We're talking about it because the date is nearly upon us.
Oh no, 21.12.2012 all over again
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With a top heavy population pyramid, more resources have to be diverted to caring for the elderly, therefore less for raising the young - a self reinforcing mechanism.<p>When actually given the choice, many women are choosing <i>not</i> to have children, for good reasons. E.g. disruption of careers, physical effects on the body, being tied to a partner, financial drain.<p>Until we face up to both these issues, demographic collapse will continue - humanity will simply evaporate.
According to some people, AI will take most of those jobs anyway, so maybe it all works out in the end :)
.. humanity will be replaced by the subset of it which continues to have children.<p>If a subgroup actually has children at above replacement, then as the other groups shrink, they will be a larger and larger fraction of the population.
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I think we're already at a doomsday for population. The inertia of such a large world running on capitalism means we can't do anything about our problems any more, so I feel the bullet has been effectively fired. We're just watching it in slow motion.
I'm not sure what you mean by "capitalism", but the only reason the world's population is so large is that critical technologies like steel, cement, and nitrogen-based fertilizers have been deployed widely. Free markets and the profit motive have been critical drivers of this wide deployment. There are problems with these industries being so strongly profit-motivated, but it seems difficult to figure out what to do about those problems while maintaining current populations levels and material prosperity.
> it seems difficult to figure out what to do about those problems while maintaining current populations levels and material prosperity.<p>Pretty sure that's the point of the comment you're replying to.
Capitalism means we can only take actions that benefit individuals in the short term (so, arms race). And the large population means inertia in that incorrect direction.
Again, I don't know what you mean by "capitalism", but it's simply not that case that "we can only take actions that benefit individuals in the short term". In the US context, it's certainly true that many companies make many decisions that are driven by short-term profits, but they also make many decisions that are driven by longer timelines (e.g. capital expenditures). I think the same holds true for non-profit entities, including governments (it's a mix of short-term and long-term thinking).<p>I think a better line of attack is that externalities are poorly accounted for in our current economic system.
It's pretty clear you do understand what they mean by "capitalism", then.<p>At this point in many countries the institutions of power have been captured by the owners of capital and many of the issues facing modern society are a direct result of this.<p>People will always act in their best interest and along the interests of their class, and no class is more class conscious than the capital owning class. In the US, this informs policy, which is generally geared at making the capital owning class more money at the expense of everyone else.<p>I don't see any other reason for us to have such excess and have it all seemingly go to waste. We could solve world hunger right now with our advances in technology and [corporate] central planning but that would never happen under this economic system.
Yet it will somehow work out. Not ideally, thats just not humane way, in fact probably quite messily, but folks in few decades will look back on whats just another period of history. Some ups, some downs, some mild and some a bit extreme, and thats about it. Moving on, next batch of challenges ahead
It looks like both the climate and biodiversity will be a lot worse than now (with appropriate great migrations). Not sure what is able to compensate for that. Although indeed humans appear able to adjust to any kind of environment.
AI agent diversity will be on the upswing, so we've got that going for us. We'll also be more insulated from the climate by virtue of all of our bodies being lashed together into a machine and flesh lattice controlled by the executive overmind.<p>What remains of humanity will be safely cocooned inside the biomechanical membrane between the chaotic outside world and whatever environment the compute prefers. The perspiration of its leviathan breaths and a circulatory system that pumps coolant will ensure the temperature differential.<p>Like how single cell organisms were engulfed into multicellular organisms, so shall our descendants be engulfed. Countless immobile interconnected bio-systems with humanity as its ancestor. They'll less adaptive than us but more optimally specialized. I wonder how recognizable humanity would be when we're tessellated into one large interconnected amalgamation. Furthermore, I wonder how many generations we have left where we'll still need a face and outward looking eyes. Skin cells don't need flagella after all.
Although I think there's a good chance that this will happen there's no reason to assume that we'll be better or at most slightly worse in the future just because that's all we've experienced in (recent) human history, it's a sort of survivorship bias.
Things will stabilise somewhere. Not sure at what population level and what technological level. But I am sure at some point they start to rise again. It won't be downward trend to zero for forever.
I do think so, but like you said, messily.
> folks in few decades will look back on whats just another period of history<p>I mean, of course. I also worry about French Revolution and WWII less then people who had to live it.
This is a Western view not necessarily seen in Asia, such as China which does seem to be solving their problems just fine.
You're making the mistake of not looking down the road far enough. "China's developing rapidly and has all these cool EVs, looks like smooth sailing til the end of time for them!" Their male/female imbalance and TFR < 1 are absolutely massive looming issues. Maybe they'll advance to the "robots do everything and no one ever has to work" end-game and then those things won't really matter, but I wouldn't bet on it.
I would. Why wouldn't you bet on it these days? It's also not as if any country can do better as basically every country has declining fertility rates.<p>And either way I was specifically responding to the point the commenter above me made, that capitalism can't help fix the issues, and my point is that China is fairly capitalist yet they've found ways to fix at least some of their issues. Not sure why you took that to mean that <i>all</i> of their issues will be fixed, that's a straw man.
The robot thing was also what japan bet on in the 90s
Seriously? China is one of the top polluters and it's a horrible country to live in. No one is solving climate change. The problem is worse than ever. None of the serious problems are being solved. Only made worse.
Relevant xkcd - <a href="https://xkcd.com/605/" rel="nofollow">https://xkcd.com/605/</a>
I’m as skeptical of underpopulation doomerism as I was about the previous overpopulation panic.<p>Both commit the fallacy of assuming present trends remain in place indefinitely and ignoring technology.<p>They also both tend to be racist. Overpopulation was always about too many of the “wrong” people while underpopulation is about not enough of the “right” people.
The real "doomsday" is the fact that we no longer have the population growth to sustain the increases that markets demand while simultaneously not alienating the ever-loving hell out of the labor and customers that capital depend upon for those increases. It's already leading to socio-economic and political problems.
Spent a few years doing population projections for regional planning and the thing that always got lost was how sensitive the long run numbers are to small fertility and migration assumptions.
Exponentials, let alone super-exponentials, will tend to do that. As the article notes, the biggest issue is assuming that the system you're modelling doesn't have any negative feedback loops that would stabilise it.
The same is true of investment and retirement calculations. Little differences in the estimation of an exponent will compound to huge differences in the long run.
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I argue that the depopulation fears are the second coming of Malthus. And like Malthus, they will be as spectacularly wrong.<p>Malthus’ problem was that it was easier for him to imagine the end of the world, then the end of Mercantilism. That he simply could not imagine that the large cargo ships would be used to trade in a globalized economy instead of upholding government monopoly over colonies.<p>Similarly, today’s doomers have an easier time imagining the end of the world, then the end of capitalism. That society will rather let it self fail rather then socializing the vast wealth we have created and is currently hoarded by a handful of billionaires, and instead distribute it justly where it is needed, e.g. as retirement to our aging population or as as subsidies to shrinking school classrooms.
It seems to me that with natural selection, women who still choose to have children today despite having an education, employment, and all of the other factors that seem to harm the birth rate, their children will likely have as many children as they did or more, even with the same gift of modernity their parents had, and this issue will stabilize or we’ll resume population growth in 50-100 years.
Not sure why you're being down voted. Maybe because it's distasteful? Doesn't make it false. We are in a period of adapting to the introduction of birth control and modern conveniences. People with higher reproductive drive will reproduce and pass on the trait. People with lower reproductive drive wont. This isn't a judgement, just reality.