You are right. Americans will be fine. We’ve got enough money to fortify cities from rising waters. Well maybe not some poor areas. But we’ve never cared about the poors, so they can suffer.
The border will be where the American crisis exists. Droughts will cause the poor and hungry to flee their homes. We’ll see a refugee crisis at the border that makes today look tiny.
Oh and refugee crisis’ that are left unsolved lead to criminal activities. So we are likely to see a resurgence of ISIS. If we are really unlucky we’ll see a few strong men take over power in these countries. Combine both and we’ll have regional conflicts. Maybe some of those will bleed over to terrorism in the US.
But yeh, you are right for Americans it isn’t an existential crisis. For millions of others however it will be.
I think you need to look more closely at the wildfires in the western USA, and wet bulb temps high enough to kill people just sitting in the shade drinking water.[1] A power outage there will cause a very large number of deaths.
