Hacker News new | ask | show | jobs
by Ajedi32 6 days ago
Well, in the extreme case, human extinction seems like a pretty bad thing.
3 comments

a large organism (human populaton on earth) reaching equilibrium and ceasing to grow does not equal to human extinction... it far more likely is just a temporary contraction that will then reverse when the conditions are set for it.
Populations do not tend to grow to equilibrium and then stop. They tend to overgrow their environment, outstrip resources, and then collapse.

The result may not be extinction. But losing 90% of the human population won't feel that different if you're living through it.

A relevant book recommend, https://www.amazon.com/Collapse-Societies-Choose-Succeed-Rev.... It walks through a variety of past examples of human societies that went through this. There is no reason to believe that our current world-wide society will fare better.

> They tend to overgrow their environment, outstrip resources, and then collapse.

That's not what's happening here. Birth rates are below 2.1 in many countries who are no where close to "outstripping their resources". There are other factors causing the contraction which have nothing to do with resource limitations.

In fact it seems like it's the opposite: richer nations with more resources tend to have lower birth rates. That's the scary part because it means there's no equilibrium to be reached. Birth rates could, in theory, remain low until humanity ceases to exist.

Has any organism ever extinguished itself as you describe ? This whole human extinction thing… isn’t that catastrophising? We are a 7-8 billion individuals away from extinction.
All plausible theories I've heard for the cause of humanity's unprecedented, historically low birth rates are things that could not occur in less intelligent species. (Birth control, women's rights, hedonism enabled by modern technology, etc.)

> isn’t that catastrophising

Yes, I'm only putting that forward as the worst case scenario to make the point that this can't just be ignored. As I said in other comments, this almost certainly won't actually result in extinction because there are other corrective factors which would occur long before that, but none of those scenarios are particularly desirable either. (E.g. Civilizational collapse returning humanity to pre-industrical birth rates, global takeover by theocratic governments that ban birth control, etc.)

The only non-catastrophic corrective factors that sound plausible to me involve some kind of intentional collective action on our part that reverses the trend, which won't happen if everyone's attitude is the same as the root commenter's. (Granted, maybe there are other possible corrective factors I haven't thought of, but if so I'd like to discuss what those are rather than just have the problem dismissed with a hand wave.)

Neither the fall in birth rates nor its rise is intentional. I struggle to understand why people think a mega fauna of 7-8 billion people takes intentional decisions. An individual takes intentional decisions. Humanity … not so much I think.
Yes. Read through https://www.the-scientist.com/universe-25-experiment-69941 to see that, given a good enough environment, mice can wipe themselves out. Here is a particularly telling passage:

Eventually Universe 25 took another disturbing turn. Mice born into the chaos couldn’t form normal social bonds or engage in complex social behaviors such as courtship, mating, and pup-rearing. Instead of interacting with their peers, males compulsively groomed themselves; females stopped getting pregnant. Effectively, says Ramsden, they became “trapped in an infantile state of early development,” even when removed from Universe 25 and introduced to “normal” mice. Ultimately, the colony died out. “There’s no recovery, and that’s what was so shocking to [Calhoun],” says Ramsden.

Like the mice, our population is going into reverse. And that description of behavior, looks awfully prescient when I compare to humans on social media today...

Lack of personal space is certainly not the cause of our declining birth rates. People in wealthy countries with lots of personal space actually tend to have lower birth rates than poorer countries with less. https://data.worldbank.org/indicator/SP.DYN.TFRT.IN?most_rec...
That means we're outstripping some kind of invisible resource that's hard to measure.
The population is not "reaching equilibrium", it's shrinking. If it was reaching equilibrium you'd expect the births per women to be slowly reducing until it approaches 2.1 and then staying there. It's dropping substantially below that. And there doesn't seem to be any evidence that the contraction is temporary, the causal factors seem largely unrelated to the existing population size.
How can you say it’s not temporary if it’s just started?
Because all plausible theorized causes (birth control, global reduction in poverty enabled by technology, women's rights) are not temporary conditions. (Or at least we better hope they aren't.)
Those are just hypothesis. Here’s ankther likely hypothesis - isn’t this is a mega fauna arriving at capacity?
The problem is that's not a likely hypothesis. There's no evidence lack of capacity is the cause of declining birth rates. In fact there's strong evidence for the opposite: countries with more resources to go around tend to have lower birth rates than countries with less resources. https://data.worldbank.org/indicator/SP.DYN.TFRT.IN?most_rec... There's no equilibrium here, if anything the feedback loop is positive rather than negative. That's the concerning part.

I thought this was common knowledge, but given the reaction I'm getting in this thread I guess it's not as common as I thought and I should have explained myself better in my original comment.

I mean "capacity" isn't some magic barrier. Usually it involves increased chances for the organism in question to starve to death due to reduced availability of food. We don't seem to be that close to reaching that.
That's... not how equilibrium works. A self-balancing segway or robot doesn't reach the balance point and then freeze in place. There are oscillations. And it isn't a pretty sine wave either. Considering the massive number of factors that go into something like "global population growth", expect a VERY chaotic graph indeed, like the stock market, but worse.
Yeah fair so what.

The argument is - our current economic system can’t handle it.

Well then that’s an argument for changing it.

Actually I was replying to someone who said that we weren't reaching equilibrium, and I contended that we are. I said nothing about "our current economic system can’t handle it".
Maybe the equilibrium is below the current level. People didn't think the population rise would stop, either.
Ya but I’m 28 and have had enough with these contractions. For Christ sake can I get a sane decade so I can actually build a career. :)
its unlikely that will happen. If you read Arrighi, his hegemonic cycle narrative says that the interregnum between two hegemons is decades of chaos as the system reorganises. We seem to be heading for a US to China transition.

The last transition was British Empire to US and that was 1900-1945.

We can only hope for something better.

Yay.
I mean you can always be a farrier, lineman, septic sumper, cobbler etc…

What’s stopping you from being a welder or dentist?

I feel like this is a joke but honest answer: I worked ocean rescue for 4 years then lived with some tech folks in sf who were making literally 5-10x my salary.

What’s stopping me? Probably some combo of wanting to one day afford a home and a family without having to move to Memphis and the a sense that I’d get bored as a welder and therefore be a bad one.

Man, septic pumper tho…

Not a joke, I tried to start a trash company and be a handler on the back, but unfortunately my epilepsy got in the way
> some tech folks in sf who were making literally 5-10x my salary

Don't worry. It's temporary.

human extinction is far more likely if we keep reproducing than if we slow down. See: climate change etc
Humans are the second most populous animal on the planet. We are in no danger of extinction.
I don't know where you got that idea, but we're not even the most populous species of vertebrates on the planet (that might be chickens).

If you include arthropods, ants make it not even remotely close.

Humans and our cattle are something like 95% of all land mammals, maybe they're thinking of that.
"Land vertebrates", #1 is chickens, #2 is humans. But colloquially "animal" does not include ants or fish.
Insects I'll consider fair enough, but fish? Are you leaning on "fish isn't meat"? Otherwise, this isn't a colloquial use I'm familiar with.
Just try referring to a fish, alive or dead or cooked, as an 'animal' to your friends. Even if it doesn't sound weird to you, your friends will feel misled in the conversation, even though it's technically/scientifically correct.
In terms of biomass humans are much larger than ants.
If the trend doesn't reverse, it's mathematically guaranteed.

But realistically, I agree. Civilizational collapse would happen long before extinction, which seems like it would almost certainly return the birth rate back to pre-industrial levels. I just don't think that's a desirable outcome either.

Or, even more realistically, nations with state religions that effectively outlaw birth control and/or women's rights will take over the world, and nations which don't do those things will collapse. That also seems like a bad outcome to me.

Point is, I don't think it's wise to treat this like it's not a problem.

It's not a problem. Go look at a graph of historical world population: https://en.wikipedia.org/wiki/World_population#/media/File%3...

It's virtually flat for eons, and then in the last 100 years it shoots up like a rocket. We didn't hit the first billion people until 1800, but the 8th billion took only 11 years. (2011-2022)

This rate of exponential growth was never sustainable, and it's normal and natural that it's leveling off now.

https://en.wikipedia.org/wiki/Passenger_pigeon

> The pigeon migrated in enormous flocks, constantly searching for food, shelter, and breeding grounds, and was once the most abundant bird in North America, numbering around 3 billion, and possibly up to 5 billion.

Past performance is not indicative of future results.