The OP discusses “Full-on 1980s nuclear exchange”. I think the relevant source for a worst case scenario for the 1980’s view of nuclear winter would be the paper by Carl Sagan and associates and accompanying newsmagazine article. https://www.cooperative-individualism.org/sagan-carl_nuclear-winter-1983.htm
(I couldn’t find a free source for the full paper.)
The article contains this paragraph:
A recent, relevant worst case scenario for cataclysmic climate change is The Uninhabitable Earth by David Wallace-Wells.
From that article:
The two worst case scenarios are pretty much equally bad for the survival of the human species. The biggest difference between them is the timespan. Nuclear winter would hit humanity in a few weeks. Cataclysmic climate change will be occurring over decades. Humanity can achieve a lot over the course of decades, provided we’re sufficiently motivated.
There isn’t consensus on anything as specific as number of people affected, but I’m not sure where you get the 200 million number. That sounds more like a lowball estimate of people already affected, not anywhere close to the expected impacts.
If you want a better idea of what “worst reasonable likely” looks like, I encourage you to read Uninhabitable Earth by David Wallace-Wells. The full-length book expands on his essay here. Unfortunately, I think the scenario he discusses is most likely, not just worst case.
To answer the OP, I agree with HMS Irruncible. In the short term, nuclear war will be much more devastating. But humanity and the rest of earth’s biosphere can recover from it, even if means a 90% or even 99% drop in population for the first 20 years. Climate change, on the other hand, could create a situation where humans never recover and eventually dwindle as a species.
ETA: heh, on preview, I see Wrenching Spanners linked the same article.
I don’t think we’re going to “recover” from climate change. I think we will adapt to the new shittier conditions, and that will be the new normal. Yeah, wars will happen, human migration will happen, new massively expensive infrastructure would be required, and, the economy will suffer. A good chunk of people will die, particularly in developing countries. But I don’t think you will see death tolls like a 1980s style nuclear armageddon.
We are talking about worst case scenarios though. I do agree with you…I think we can adapt to climate change, as a species, better than we could to all out nuclear war. To me, it’s not really even a contest, even if we are talking about the absolute worst climate change scenarios I’ve seen…and, frankly, I think we will not be hitting those, regardless, though that’s not what the OP asked for. But I think the planet, overall, could adapt better to nuclear war, especially if it managed to wipe out the humans or cut us back to very low levels, than it will to climate change…and by ‘the planet’ I really mean most other species. Climate change is going to cause a LOT of extinctions…it’s happening and has been happening already. But humans? Overall, we will weather it better than we would an all out nuclear war.
Was it just about the planet though? I mean, yeah, “the planet” would recover just fine. “The planet” doesn’t care either way. If I’m not around (and I would most certainly die in a nuclear war), I’m not gonna care either.
Like I said, when I mentioned ‘the planet’ I really mean the other species that inhabit the planet. The actual planet won’t care one way or the other. It’s been through much worse than either climate change OR a full on nuclear war. It won’t notice either. But the other species on the planet are going to have a bad time, either way. IMHO, they will have a harder time with climate changes, especially in the worst case scenarios, than they would with nuclear war, as I think more humans would survive climate change and with an intact civilization (both of which are bad for most other species) than in a nuclear war.
The thing is, after a nuclear war, the remnant of humanity will have their pick of some pretty good leftovers. The cities of course will be toast, but there will still be tons of tech and structures still out there, as well as arable land. Biodiversity will strengthen, there will be more species for food and medicine. Humanity could bounce back in a big way.
With climate change… I mean, if we have 50 years to get used to the idea of all humanity trying to live on a patch the size of Texas, living off hydroponic corn and roasted giant rats… there’s not a lot of “getting ready” for that, unless you mean mentally preparing to suffer and die. Survival? Maybe. But there’s little to no chance of “bouncing back” in any meaningful way.
It’s true that temperatures were much hotter in the past. There were also no humans in those times, so there ya go.
Wait…what? You think or someone is seriously saying that in the worst case climate change scenarios that on the entire planet the only habitable parts for humans would be the size of Texas?? Seriously?? Because…well, that’s ridiculous. On what timescale do they think that the entire planet will become uninhabitable except for the land area of Texas?
I haven’t seen anything that is close to that. What I’ve seen for the worst cases is that, perhaps, much of the equatorial regions might not be habitable by humans, and that we will have sea level rise of, perhaps, 50 meters. That will be bad, no doubt but we’ll have more land for all of humanity than Texas. Do you have a link to a credible source who is seriously claiming this? I really want to know what the time frame they are positing.
Much as I’d love to spend pages haggling over the definition of “credible” and “serious” with someone who’s already certain they’ll land on the wealthy-nation escape pod, I’m gonna take a hard pass on that.
Because…well, that’s ridiculous. On what timescale do they think that the entire planet will become uninhabitable except for the land area of Texas?