Carbon caused climate change isn't a carry-ing capacity / overpopulation / over utilization issue (and is now somewhat dwarfing those issues). It is a big change that has some chance of devastating a lot of biological based support systems all at the same time.
The risk to technological civilization is not in the direct effects, but in the human mediated effects. Not that leaving on yeast and water would be that good.
I'd put it in the low single digits or maybe lower, on the basis that a cascade of things need to go wrong: first you need a climate scenario that exceeds the IPCC estimates, then you need significant damage or conflict, then you need a potential collapse event to emerge from the conflict, then the event has to trigger collapse on its own or other events have to occur and combine with it.
Curious to hear your thoughts though, because I haven't put firm numbers on anything or looked deeply into any of the research on collapse specifically.
But maybe like Kim Stanley Robinson’s recent book, it will all work together and we will make a new carbon based cryptocurrency backed by the bankers, switch to blimps and all ends well. I have kids and am teaching them to corporate with people rather than become preppers, so I guess I am optimistic de facto.
Being totally accurate when predicting the future is impossible, but discussion of the factors is useful in its own right.
I understand that climate change is progressing rapidly, is going to cause very bad things to happen (my earlier comment mentioned hundreds of millions of human deaths as an example), and should be mitigated. What I question is whether the total collapse of industrial civilisation as a result of climate change is likely to occur. This is as opposed to economic stagnation, famine, war, widespread desertification, unliveable wet-bulb temperatures, or anything else short of a total collapse.
> economic stagnation, famine, war, widespread desertification, unliveable wet-bulb temperatures
For most people those are collapse and it's definitely going to happen and will come much sooner. The video shows it's going on the worst case scenario way.
Global warming is scary because of nukes.
The timeline till we get widespread crop problems is 15-20 years.
God we did manage to fuck ourselves good and proper.
The scenarios that fall short of ending civilisation, e.g. losing hundreds of millions of lives to famine or war, are obviously still very bad. This is not to downplay climate change in the slightest. It's just... at some point, people start dying, and that frees up ecological carrying capacity again. You need to make pessimistic assumptions about a lot of positive feedback loops in ecological and social collapse to predict that all human civilisation is going to be wiped out in the sense of regressing back to before the industrial revolution.
[0] https://www.vox.com/future-perfect/2019/6/13/18660548/climat...