There are going to be a lot of climate refugees in the next quarter century. Crop failures, and literally unlivable temperatures like these. I doubt even Rwanda will be able to take them all in.
Certain crops will become untenable in some areas, but in other areas, certain crops will become tenable that once weren't.
But none of this is new, what's new (aside from the anthropogenic cause) is that Homo sapiens' usual coping mechanism of migration is no longer feasible.
This is where the problems and conflicts will come.
Climate change doesn't mean just the temperature become a few degrees warmer. The most noticeable change is that one in century event may happen annually now: extreme heat, extreme cold, floods, hurricanes, etc.
> Homo sapiens' usual coping mechanism of migration is no longer feasible.
Migration is extremely common, that most migrants do not reach Europe or the USA did not mean that they are not migrating.
I may assume that you mean that Europe/USA cannot be the destination of all of them. But, I do not even think that most people is so willing to change to a different place. They will migrate as much as needed but not more.
Sorry, I was implying "large-scale" migration as a mechanism for coping with climate change[0]. That's not really possible without massive armed conflicts in these days of nation states.
But none of this is new, what's new (aside from the anthropogenic cause) is that Homo sapiens' usual coping mechanism of migration is no longer feasible.
This is where the problems and conflicts will come.