The only hard limit on our resources that we currently know of are the energy output of our sun in the short term and the energy output of reachable stars in the long. We are not constrained on food, space, energy, etc on earth in the short term. We have only artificial political constraints where the stationary bandits ruling the various geopolitical units have subsidized the creation of narratives justifying your constraint. Humans do not consume wealth, they create it.
I think this is both trivially true an irrelevant. The fastest car that we can build is only limited by the speed of light, but we can't really make cars that fast for a vast number of reasons that I am too lazy to spell out. I am not interested in a theoretical world where if we run out of phosphorus on Earth we just make new atoms using fusion or we make rockets to mine distant asteroids. I'm interested in Earth on the 21st century, where if you interrupt the transit of boats in the Black Sea people in Africa die of hunger. We are, in fact limited in the amount of food we can produce, and although we could increase the amount of the Earth surface devoted to crops, that comes at a high ecological cost. Same thing for many other resources.
We are constrained on food. There is a limited among of land suitable for farming, most of which is in use, a limited amount of fresh water, and we are close to ceilings on optimising agriculture with machinery and fertilisers. The Ukranian war is affecting food security, which means there's no slack.
Now I think you were correct and I failed to see what you meant at the time. I should have spent more time considering your input and less time at crafting a smart sounding reply. Thanks!
In my model of the world works, overpopulation is in fact a big problem. In general, the more people you have, the less resources you have to share among those people. A decreasing population would be in fact good news, although maybe not in the short term.
That is true in general, but we are nowhere near the resource limit currently, provided we manage them properly. There are existing low- to high-tech measures, like reducing cattle population, improving efficiency of existing HVAC systems, switching to electric, GMO crops, improved renewable and nuclear energy sources, smaller dwelling footprint per person, and many others. This doesn't include any new tech, like fusion, vat meat, energy beaming from space, moon bases etc.
With an eye on conservation of resources, without giving up quality of life, the planet can probably easily support an order of magnitude more people than there are now.
I think the tweet is saying a lot less than it seems like it is.
In particular, the risk of civilization collapse due to climate change is really small. There are all kinds of bad things that might happen due to climate change, and I'm strongly in favor of working hard and spending a lot of resources to fight it, but I think it's < 5% for even business as usual to lead to civilizational collapse due to climate change.
Suppose Musk thinks that as well -- and in fact probably his estimate is lower than mine for collapse. Now he's only needs to think that there's a small chance of collapse due to low birth rates for it to be greater than the civilizational risk of climate change.
It’s true that more people means we each get a smaller share of the natural resources, but more people increases the benefits of innovation and specialization. In particular, the benefits of new technology scale linearly with the population (everyone can use the) but the costs of research do not. Since the world is getter richer over time (even as the population increases), the average human is clearly net positive.
Most of the world is covered with people. Economy and its productivity cannot be measured today. The measures or measuring stick we use to explain the world today is inadeqate. Retrospective analysis of humanity is nice. But very risky business since nothing today ressembless the past.
To add - undercutting the human demographic pyramid has serious social drawback. Capital grows on influx of human population. Unfortunately the idea that human demographic growth is necessary is probably bias based around human psychology and large capital, that maintains its relevance merely by generating profit. If we neglect these rather stupid ideas, we are left with infinite sea of positive options where less population is always, better. We are not few. We are billions.
This model is wrong because it doesn't take into account the enormous gains to productivity you get from various kinds of economies of scale, particularly from the possibility of specialization and trade between different people.
Even if you had all of the technical knowledge we have right now, a town with 1000 people would be much poorer on a per person basis than we are now. There would simply not be enough people working on enough kinds of different jobs to make most of what makes the modern world possible work. For example, how do you build a modern laptop with only 1000 people? Even if all 1000 were exceptionally talented, that's just not enough scale for you to be able to produce a laptop.
In addition, there are large positive externalities from having additional people, because a lot of research is high fixed cost and small marginal cost. It doesn't cost ten times more in research effort to make ten rockets compared to making one rocket. So the more people you have who are working on figuring out how stuff works and spreading that information around, the more productive everyone becomes.
You can think of this as a tradeoff: the more people you have the more you're able to produce per person due to the effects mentioned above, but the less natural resources you have per person to go around. If you view this as a purely static problem then there would presumably be some "optimal level of population" at which income or wealth per person is maximized, so the question is how big this optimal level actually is. I think all available signs right now point to us being far below the level of population that would be optimal: the bottleneck on our productivity and economic growth is not resource constraints but the lack of enough people.
I roughly agree with this model, I disagree with "all available signs right now point to us being far below the population level tat would be optimal". I don't know why you think that the bottleneck is "the lack of enough people".
To sustain high tech-driven growth rates, we probably need (pre-real-AI) an increasing population of increasingly specialized and increasingly long-lived researchers+engineers at every intelligence threshold - as we advance, it takes longer to climb up on giants' shoulders. It's unclear what the needs are for below-threshold population (not zero, yet). Probably Elon is intentionally not being explicit about the eugenic-adjacent angle of the situation.
I have a terse answer: If you're not growing, you're dying.
Somebody has to support the elderly people. The other aspect is the capitalism and consumerism point of view. But all this hopefully will be good for the planet and other species.
we need ideas to have econ growth, we need humans to have ideas, having fewer humans will lead to econ stagnation. This is the summary of the argument https://www.cold-takes.com/what-is-economic-growth/
But econ growth does not necessarily mean better lives on average if there are also more humans to feed and shelter. In the current context, if you want more ideas, you'd have a better ROI by investing in education.
Note that decline is not collapse is not extinction.
https://astralcodexten.substack.com/p/slightly-against-underpopulation
If human lives are good, depopulation should not be pursued. If instead you only value avg QOL, there are many human lives you'd want to prevent. But anyone claiming moral authority to do so should be intensely scrutinized.
Isn't he just trying to win points from his new republican buddies by disowning earlier interest in climate change and aligning himself more with a cluster of socially conservative views (anti abortion, love of big patriarchal families, fear of being outgrown by the out group etc)?
There's probably some truth (well, not in the literal prediction sense; more the plausible model sense) in the tweet. The motivation for both the tweet and the like is probably more about love of contrarianism and enjoyment of heterodox modeling than actual information.
Start with it as a literal comparison. If you don't think global warming is a near-term risk to civilization in the first place, then there are a LOT of things which are plausibly bigger risks. Then consider how to interpret "Population collapse due to low birth rates". one can imagine paths to a collapse of innovation and commerce, followed by further supply-chain failures and food riots.
Seems pretty low likelihood to me, but like most altruism debates, I'm happy if anyone wants to devote energy to such things, even if I don't find it compelling.
Elon Musk published a few hours this tweet:
"Population collapse due to low birth rates is a much bigger risk to civilization than global warming"
Robin Hanson, who is something for whom I feel a lot of intellectual respect, liked the tweet.
In my model of the world works, overpopulation is in fact a big problem. In general, the more people you have, the less resources you have to share among those people. A decreasing population would be in fact good news, although maybe not in the short term.
Can you help me understand what are Elon/Robin seeing that I am not?
A couple of extra points for the sake of clarity:
I do understand that, in the current system, having an aging population is a problem because many resources go toward people that reach an old age
AI might or might not end the world. Let's assume in this scenario that it does not and we have many more decades ahead