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.

▲

Ajedi32 5 hours ago | parent [-]

> 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.

▲

kranke155 5 hours ago | parent [-]

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.

▲

Ajedi32 4 hours ago | parent | next [-]

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.)

▲

kranke155 4 hours ago | parent [-]

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.

▲

Ajedi32 4 hours ago | parent [-]

Correct, but my point is unless we find a way to intentionally fix the problem we're going to unintentionally walk into a disaster.

I don't fault your logic, but I don't want to accept that disaster is inevitable.

	▲	kranke155 4 hours ago \| parent [-]
		What disaster is this that you foresee ?

▲

btilly 5 hours ago | parent | prev [-]

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...

▲

Ajedi32 4 hours ago | parent [-]

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...

	▲	M95D 3 hours ago \| parent [-]
		> People in wealthy countries with lots of personal space How did you reach that conclusion?