That scenario is so complicated and requires so many tenuous assumptions that it might just happen anyway. The demographic stats already suggest that the future is going to be very African, that there will be lots of migration and we've had a couple of migration waves triggered by stuff that isn't climate change.
The problem isn't climate, it is that there are too many people and they keep having kids. Although right now the trend in global birth rates is extremely promising and if that keeps up (keeps down?) we'll be fine.
I don't understand what you mean by "tenuous assumptions".
There's almost certainly going to be areas which are already near the limits of human survivability without air conditioning (high wet bulb temperatures of more than 30 degrees Celsius) and some of those areas will become even hotter in a warming earth.
The problem most definitely is a changing climate and especially if it becomes unstable as we rely on stable conditions to grow food. Yes, there are too many people, but we're not going to have to wait for declining birth rates as lots of people will die from famine and wars due to the pressures involved with climate change.
You start with "climate is changing", then there are a lot of implicit steps and you end up at "there's going to be a mass movement" and transition to "most likely lead to famine and wars". There are two jumps there; both unlikely to play out.
People might import food from newly created foodbowls for example - as far as I recall China technically can't feed its own population without imports and that hasn't caused any famines. Or it may turn out edible plants can adapt really easily to temperatures in the 40+ range, it wouldn't be the first time we've adjusted our food to suit conditions that it wouldn't naturally cope with.
And we already have mass movements; something like 4% humans [0] migrated during their life. Things like people fleeing world wars I & II were probably extreme too. The movements were generally net positives for the receiving country. It isn't clear mass movements do lead to wars, or implicitly need to.
And to top it all off, people might just not migrate. It is most likely cheaper to build local shelters than uproot a family and move countries. As I mentioned upthread, if you describe normal conditions in a random Russian town it sounds like hell on earth - it is hell on earth, 9th circle stuff - people still live there. No mass migrations.
Okay, you don't seem to appreciate the scale of the issues.
It's not just a case of getting crops to adapt to higher temperatures - it's the unpredictability of rainfall that's going to cause (and is starting to cause) crop failures. People have already suffered famines in countries where crops have failed due to unusual dry or wet periods, so it's hardly a jump to predict that those kinds of famines are going to become more frequent and severe.
You don't seem to understand the concept of high wet bulb temperatures either as building a shelter is not going to be of any help unless those shelters have extensive cooling or air conditioning. Humans just can't survive a wet bulb temperature of more than 31 degrees Celsius or so, even with unlimited access to drinking water and fans.
I don't see how it is possible for people to continue living in their current country if they have to cope with lack of food, water and survivable temperatures. I think you're being excessively optimistic, but I hope you're right. Unfortunately, experts don't agree with you.
Looking at https://ourworldindata.org/famines though, we've pretty much solved famine as a problem. You're assuming that we can't do it a 2nd time if the climate changes - but we probably can. Organising food isn't a new problem for society, we've been working on this for all of recorded history and gotten really good at it.
I can imagine a brutal transitional famine if we get caught unprepared; could happen. But so many people are looking at climate change it seems like the people who need to know would know. The farmers know about it, the insurers know about it, the governments know, so on and so forth. It might just as easily be a non-issue.
> ... building a shelter is not going to be of any help unless those shelters have extensive cooling or air conditioning...
Yep. If it were you, would you build an extensive shelter with air conditioning or declare war on someone a continent away? I think the shelter is the easy option. It is roughly analogous to a snowstorm - I have relatives who are prepared to live in isolation for a good month.
Climate events trying to kill us is not all that new. Surprises hurt, but if they happen a few times we'll just start taking them in stride.
That link to famines only goes up to 2016 which is missing out the famines in Yemen, South Sudan, Unity State, Somalia, Nigeria, Tigray, Madagascar and arguably Gaza Strip and Palestine.
I would disagree that we've gotten really good at organising food - we've gotten good at organising food for wealthy countries, but have done very little for poorer people - they usually just starve when crops fail.
I think you're treating climate change as a single event that can be dealt with, but the truth is closer to a fast changing series of events that will overwhelm governments as they'll still be reacting to the first catastrophe when the next one comes and then the next one and so on. Despite your optimism, this is exactly the kind of thing that destroys civilisations. It's like an insurance company hedging money against a once-in-a-hundred years event, but when those events happen every couple of years, the company will find itself bankrupt.
I have doubts about how easy it is to build an extensive shelter with air conditioning in areas that don't even have an electricity supply. Why would we suddenly start to care about those poorer regions when we don't currently? It's far more realistic that the richer countries will make token statements and then just leave people to die, which will inevitably involve people moving from the uninhabitable areas into places that can support human life without continual money and investment.
You seem to be judging the climate crisis with previous events, when the big problem is that we're seeing unprecedented weather events - it's not going to be like anything that we've encountered previously.
> I have doubts about how easy it is to build an extensive shelter with air conditioning in areas that don't even have an electricity supply.
Picking on this as the best example of the thinking; the problem here is that people are living in terrible conditions. The urgency of the situation ... almost doesn't change if they are about to be hit by a new crisis in 20 years. It is urgent, right now, to set up an electrical plant, grid and other infrastructure. Conditions are already bad enough that they should mass-migrate.
I agree the west is probably going to leave Africa to their own devices; but the Africans have agency too. They should copy the successful parts of what China did as a matter of life-and-death urgency.
> I think you're treating climate change as a single event that can be dealt with, but the truth is closer to a fast changing series of events that will overwhelm governments as they'll still be reacting to the first catastrophe when the next one comes and then the next one and so on.
Governments don't provide food, build shelter or keep people cool in summer (well, I suppose public housing is an exception but it isn't the norm). Them being overwhelmed doesn't have that much bearing on the important stuff.
> It's like an insurance company hedging money against a once-in-a-hundred years event, but when those events happen every couple of years, the company will find itself bankrupt.
That seems unlikely, actually. They'd adjust their coverage and premiums to remain profitable. Insurance companies hire some of the best actuaries and forecasters. Your positing that they're going to be caught completely by surprise from things that are common knowledge problems - always possible I suppose, but not really the baseline expectation.
> when the big problem is that we're seeing unprecedented weather events - it's not going to be like anything that we've encountered previously
Yes and no. They will be unprecedented, but we're not talking magnitudes that are that outside the human experience. The pitch I'm seeing seems to be there will be week-long (maybe month-long in some areas) periods where humans can't survive without shelter. Some of the most prosperous regions of the earth already have that problem.
And you've convinced me that people currently so poor as to be at risk of famine are probably going to be hit by famines; but not that anyone else is. So it seems quite likely that the status quo will be preserved. And the solution is for the poorer countries to build up their industry, not for anyone else to shrink theirs.
The problem isn't climate, it is that there are too many people and they keep having kids. Although right now the trend in global birth rates is extremely promising and if that keeps up (keeps down?) we'll be fine.