Serious question: I always see 'humans will survive' in these kinds of posts. Why? We know most of the past species are extinct, we are in the middle of a mass extinction event, the climate crisis hasn't even fully begun, and there are other serious problems coming.
So I don't want to be negative, but I do want to stay realistic. Does someone know why humans will survive, and on which time scale this prediction is valid .
People have been inhabiting the Arctic for millennia, and that's a pretty inhospitable place. Granted, it's technologically easier to heat than to cool (just eat lots of fat)
We don't have reliable data that an advanced civilization of our level (yes, we're advanced comparing to many our ancestors) goes extinct. Particularly for reasons like this. So we naturally not sure. On the other hand, we see some examples of wonderful inventiveness - say, in time of a war, but also in time of great geographical discoveries, technology and science achievements etc. So for many it feels like an open question.
As for validity time scale, I'd like to see research myself.
We have some examples. Just look at Petra and some Mayan cities... They fell because climate stopped spring people there - they ran out of water and fell to either starvation or disease.
Mostly they moved elsewhere, but on planet scale that would be much more problematic.
Citing a post in this same discussion: warming by 5 degrees will cause all phytoplankton to die off and as a result we'll run out of oxygen. So no, that's not enough.
Even if it would be, how would you feed these people? How would their underground cave get power for light etc in a CO2-negative world?
AFAIK, the 'biosphere 2' experiment and the experiences with the space stations demonstrated humanity is not capable of surviving long term without mother earth. There are plenty of unknown unknowns.
Breeder reactors are really nice in that they produce lots of energy that you can use to produce food and oxygen. Biosphere 2 was a hippy project that tried to reproduce a complex ecosystem that nobody really understood. The Russians had much more pragmatic approaches. For this project https://en.wikipedia.org/wiki/BIOS-3 it's much easier to see how it could scale up to true self-containment.
So I don't want to be negative, but I do want to stay realistic. Does someone know why humans will survive, and on which time scale this prediction is valid .