Comment by pingou
7 hours ago
We are special in many ways, we have technology, we are everywhere, and we can think and plan (although considering global warming that is debatable). Global warming would have to create dramatic conditions everywhere on the planet, not leaving any small pocket of survivability to make humans extinct.
Possible? Theoretically yes, but pretty unlikely. But obviously extreme global warming would be a catastrophe even if some of humanity survive.
Technology depends on a lot of people cooperating around the globe. Disrupt a few critical chains (power generation, fertilizers, computers), add a bit of good old war and you'll soon be in the era before Haber process and a lot of people die. And then the remaining people will have trouble keeping that level of technology with how sudden the change would be.
Well yes that's what I said, it could destroy civilisations and their technology. It seems much harder to kill every isolated tribe in the whole world, and every survivors of the destroyed civilisations.
There's little evidence that humans are able or willing to cooperate at this scale. See: the past century of climate change.
Runaway greenhouse effects on other planets have resulted in surface temps of 400C+
Yes, but Venus has 93 times the atmospheric pressure of Earth, and it's overwhelmingly CO2.
Earth isn't likely to get a true runaway like that until the sun gets another billion or so years on the clock, and when it does it will be water vapour as the oceans are promoted to atmosphere.
What we're doing to ourselves is still bad, of course, but it's nowhere near that bad.
Is there a possible scenario for that on earth, that results in every place on earth having a temperature non survivable by humans?
For temperatures not survivable by humans we're talking about a sustained wet bulb of >=36C
On whether it's probable, I'd lean towards no but I'm not qualified. The certainty that I read in the parent comment was mainly what I was pushing back against. On a re-read though it's much less certain (either edited or perhaps I massively misinterpreted it the first time around). Runaway implies positive feedback which is hard to gauge, was all I intended to say