Hacker News Reader

The sad thing about the 1 child policy is research shows you don't need to do it in an authoritarian manner to get similar results. Like in Iran, they subsidized birth control and went on an education & promotion spree and it worked too well. Iran also had a government promoted baby boom similar to what china went through also.

I was under the impression the birth rate in China was already falling quickly when the 1 child policy was introduced. That’s not to say there wasn’t abuse going on but that the over population problem was already solving itself.

Your second scenario is what is often promoted despite being hard to believe at this stage. Your third scenario is very likely IMO. Your first scenario sounds like the world runs on magic beans and somehow things will just work themselves out without any intervention or disaster (your third scenario) ...

I find opinions like these to be somewhat disconcerting. I don't know terribly much about demographics, but people who study demographics and economic development seem to fairly consistently agree that global population /will/ level off. At the core, the reasoning is simple -- as women become better educated and countries develop economically, birth rates drop, with no exceptions that I am aware of. The United Nations projects that the global population will level off at 12 billion around 2100.

When I was a kid, there were about 3.5 billion people on earth. I've watched that double. Growth of 3.5 billion people. You shug off another 4 to 5 billion like it's no big deal. Maybe you're just happy to hear a prediction if leveling off, and the number is meaningless. Let me tell you, 3 to 4 billion is a LOT of people. I remember when it was ALL the people, and what it looks like to have that many more. Dont kids yourself, it's a LOT of people. The notion that the entire world will modernize and have a reduced birthrate is also an assumption. I hope we can handle it.

Yes but the scenarios 2 to 3 mentioned in the comment above are purely speculative. They in fact go contrary to the weight of more recent demographic historical evidence so far and insofar as there's a major scientific consensus of any kind on population growth, it's weighted heavily in favor of the idea that population will stabilize by or before 2100. Even the 12 billion figure is exceptionally high. The majority I've seen indicate 11 billion or less, many 10 billion and the lower professional estimates argue we might see a world population of only 9 billion or so by 2100, if I recall correctly. All this takes aside new energy, crop and general technological prospects for good human development. Currently, more people than ever are indeed living better than ever despite the population having doubled since the mid 1970s or so and the current biggest problems facing populations in need almost entirely consist of politically caused shortages, not literal absolute resource shortages.

One other thing to keep in mind as well: much of our current population explosion isn't even due to massive birth rates. It's the result of much lower infant mortality. If we were to still have the infant mortality rates we had in the beginnings of the 20th century with current global birth rates, i'd even speculate that population would already be declining. Since said birth rates continue to decline, the trend looks good globally.

Very fair point. I definitely agree with you and the article in general -- demographics definitely deserves to be the #1 big important force that will shape the world.

Can we feed 12 billion people for ~100 years without ruining the rest of the biosphere (assuming the population peaks there then shrinks)?

I think it's possible in a technological sense -- my understanding is that we can produce enough food, and little technological development from where we are today is necessary to scale this to 12 billion people. It's distributing the food -- transporting it, dealing with economics/politics that is difficult. For example, western countries could in principle, but won't in practice, just provide food to north korea.

I think it's going to be incredibly challenging to avoid potentially catastrophic harm to the environment due to politics and incentive structures. As far as food goes, beef and pistachios stand out to me as particularly environmentally harmful/wasteful, due to methane from cows and enormous water requirements for nuts, and it's not clear that anyone can change incentive structures to sufficiently change peoples' habits regarding these foods. (though in the grand scheme of things my understanding is beef and pistachios pale in comparison to habits such as flying for climate change.) I usually see people who think about this topic discourage the idea of technological development as a magic bullet, but I'm biased in this direction (it's also fitting for people who read hacker news) -- advances like impossible foods are inspiring to me. They've created "fake meat" aimed at traditional meat-eaters, allowing people like me to keep our luxurious food preferences in a manner that's much more environmentally friendly. They've had an impressive amount of success so far, with deals with chains like Burger King. If they can convert a sizable fraction of meat-eaters, they will have made an enormous impact on climate change.

> despite being hard to believe at this stage.

You're putting it mildly. The second scenario is a delusional fantasy, I don't understand how it can be mentioned seriously.

We may end up closer to the first scenario thanks to the prospects of the third one. I hope we do.

There is a 4th scenario: the population peaks and begins to fall. The article talks about how growth rates are falling all over the world. Many countries already have birthrates below replacement level, and the world as whole will reach that by 2085, according to UN projections. People living longer is a countervailing force, but declining population is still a pretty likely future.

(Can't link to the specific stat, but take a look here for raw data and projections https://population.un.org/wpp/DataQuery/)

the book "limits to growth" from the 70s has a bunch of discussion around potential future trajectories for human population, based on modelling & simulation.

the authors discuss & model different interventions & policies that could be put in place to try to prevent the "overshoot and collapse" type scenario where human population peaks and then crashes.

some academics argue that things are tracking somewhat consistently with projections of the modelling from 50 years ago: https://www.theguardian.com/commentisfree/2014/sep/02/limits...

a lot of the critique of the "limits to growth" modelling is of the form "a crash in global population was predicted by time T, but that didn't happen", but the modelling doesn't really try to make predictions in terms of specific events happening at specific timescales, it's focused on understanding the underlying behaviour based on the structure of the system.

>There are 3 futures. One where population naturally levels off and finds a sustainable level, one where growth turns out to be truly exponential in defiance of physical limits and one where a lot of people discover they can't be supported by what is on offer and die of starvation or violence.

I think theres a 4th future, which is that natural selection and evolution ultimately control population on a global scale and is the single biggest factor influencing the world today.

You are describing the parents 3rd option in a more flowery fashion, how do you think natural selection works except through death and violence? If that isn't happening then some kind of equilibrium like situation 1 has taken root.

Are your first and third scenarios mutually exclusive?