This. It would take something truly catastrophic to make humans extinct now that there are so many of us on every part of the globe.

Climate change won't cut it, neither would total nuclear war.

Even if you had something like an impact big enough to superheat the entire atmosphere, enough humans might survive inside buildings, basements, subways, etc to carry on.

Modern civilization though is a lot more fragile. It's possible to blast us back to pre-industrial times and the easy to access resources are mostly gone. It's not clear that we could bootstrap a second industrial revolution easily.

eh. you underestimate global thermonuclear war.

Global thermonuclear war would destroy technological civilization, but even now there are small groups of pastoralists and hunter-gatherers in remote regions who use only muscle power and do not need factory manufactured goods. Uncontacted tribes [1] would go on living much as usual if a nuclear war depopulated industrialized regions.

There would be some increase in mortality among remote tribes as radioactive fallout from a large scale nuclear war drifted down globally, but that wouldn't be enough to cause human extinction.

[1] https://en.wikipedia.org/wiki/Uncontacted_peoples

> but even now there are small groups of pastoralists and hunter-gatherers in remote regions who use only muscle power and do not need factory manufactured goods.

Good luck getting them to adopt your useless ass in the post-apocalypse.

Large parts of the world would be untouched (Africa, South America, Middle East). You might get a nuclear winter, but many people would still survive that.

OTOH our garbage and wreckage will provide a lot of resources. For example there may not be any easily accessible copper deposits, but there are a lot of wires to scavenge. No easily accessible fossil fuels, but the amount of plastic in garbage dumps makes them a fossil fuel source.

To be clear I don't think anthropogenic climate change will cause human extinction. But a terrible series of volcanos could absolutely turn Earth into a colder Venus for, say, a couple hundred years - pelagic vertebrates and certain microbes would be ok, but I am not sure humanity would survive more than a few generations, even in underground sci-fi bunkers.

https://en.wikipedia.org/wiki/Permian–Triassic_extinction_ev...

It would have to be worse than the previous volcanic extinction events, which were massive. It's not clear the Earth can even do that anymore.

> It's not clear the Earth can even do that anymore.

This is a good point, but the event wouldn't need to be more volcanic so much as that volcanism would need to ignite more carbon-containing materials - naively I would expect there to me more "fuel" in the Earth than there was 300m years ago.

That's also a good point

> But a terrible series of volcanos could absolutely turn Earth into a colder Venus for, say, a couple hundred years

Minoans went from the thriving trading center of the Mediterranean with written language as old as Egyptian Hieroglyphics to seemingly irrelevant for a while during the Bronze Age because volcanic eruptions seemed to have turned the air they breathed to poison. Not to mention places allegedly hit by the fall of volcanic ash whose remains are so far deep we only speculate they lived there.

With the proper breeding techniques and a ratio of say, ten females to each male, I would guess that they could then work their way back to the present gross national product within say, twenty years.

This is like a rejected version of one of Heinlein’s omni-competent hero fantasies. Humans aren’t fruit flies, with anll individuals interchangeable and ready for life shortly after birth. Even ignoring the dubious math getting to those numbers, think about the skills and equipment. In your scenario, everyone’s so busy taking care of food and childcare that they’re not going to have time to realize that they don’t have teachers for all of the subjects or specialists who can maintain intricate manufacturing lines. The people who work on semiconductors can’t just switch to make pharmaceuticals or engines!

Regrettably, yes. But it is, you know, a sacrifice required for the future of the human race. I hasten to add that since each man will be required to do prodigious... service along these lines, the women will have to be selected for their sexual characteristics which will have to be of a highly stimulating nature.

Because the men have almost all killed one another off, leaving mostly those who managed to stay out of the fight? Who is supposed to teach the kids skills to rebuild civilization if who's left are wholly occupied with reproducing? Will you kill the infant boys too?

// ratio of ten females //

I’m really hoping this is a ironic literary reference to “How I learned to stop worrying and love the bomb”

Can you do a USSR accent? We need an Ambassador de Sadesky in the sibling thread.

Da, Komrade!

Do you need the line?

Why would more women survive than men? Leaving asside how difficult it is for for a single woman to raise children in a post-apocalyptic society

Also the population for many of these earlier humans was much much lower. It's hard to give accurate population counts for many of these earlier humans – we don't know all that much about Denisovans – but for Neanderthals the total population was in the tens of thousands.

here are some non-human species "we eliminated" in Latin naming system

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

We are at an imminent threat of extinction.

We are? You have evidence for this?

Yes. The near future will decide if and to what extent the life on Earth will survive because of what those madmen did.

>The other species are gone because we eliminated or out competed them.

And homo cyberneticus will do it to us.

It’s an abstraction that can’t exert any physical force to preserve its own existence without our cooperation.

Our ancestors may have almost gone extinct 900M years ago. Some researchers looking at genetic data believe we were down to 1280 individuals [1].

Those were pre-human ancestors, but humans aren't special, we are just animals that are more destructive than any species that came before us.

Hubris will likely play a large role in any possible future human extinction event. E.g., doing nothing to curb climate change because we are "smart" and invincible and/or god(s) wouldn't allow things to get that bad, a deadly pathogen develops resistance to all antibiotics because of free-feeding antibiotics in factory farming animal flesh, we use nuclear weapons in conflict X believing it will not escalate (George "Baby" Bush, "I want nuclear weapons I can use" [actual quote]), a pathogen intentionally developed to both spread quickly and be extremely deadly (because we can), that somehow... "no one could ever foresee the possibility..." escaped the lab-- or maybe it will be a large meteor impact wiping out humans (and other large animals) across the globe like a kid stomping on an ant hill.

[1] https://www.scientificamerican.com/article/human-ancestors-n...

I don't disagree with the thrust of your comment but how does one identify the presence or absence of hubris from fossilized remains?

Genetic data is misleading; it only means that number of people had surviving descendants. It's entirely possible that the population never dropped below N, but one particular tribe gradually became dominant and genocided everyone else. Remember that endogamy is the default!

"900M years" is a typo, right? That's the time of the earliest sponge-like animals ever...

I'd hope so.

The linked article talks about the human bottle neck 900,000 years ago, that's almost a million years, but well short of 900 million.

Yeah, should have been 900K. Can't edit.