Powell warned about the the vulnerable Colorado river nearly 150 years ago. Cadillac Desert laid out the inevitable drought collapse in detail to stopped up ears. The immigration problem won't be limited to India and Africa headed for the EU. People on the American East Coast will be getting ugly re migrants - AMERICAN migrants - from the American West. It's not as if you need to back that far, just to 1930 to see all the hearts harden within minutes towards the drought refugees.

Humans will survive and get through this but at vastly reduced numbers and those who will survive will probably not be people you would care to have to dinner. They won't even like one another.