Speaking for the US many populated arid areas are completely unsustainable as population centers (ironically also where most people in the US have been moving for awhile now), especially because water resources haven’t been managed rationally in many arid areas. This story will absolutely be a global one though, see Tehran for one massive example, Lake Mead for another. No water and deadly heat waves are going to make for limitless ghost town tourism attraction opportunities!
The future is bright for abandoned building photography communities!
I think this will happen for reasons other than water too. So many towns in America were built to be in close proximity to train lines, who’s locations today makes no strategic or economic sense.
I believe many will hit critically low population levels where they can no longer support hospitals, schools, grocery stores, churches, etc