To give everyone the American quality of life would require 5 earths of resources.
It's less "billions must die" and more "shit, billions are going to die".
The standard of living that Americans have is beyond the reach of billions, but they won't simply give up. They'll devour their nations from the inside out fighting over who gets to be middle class.
Meanwhile the U.S. and E.U. sol will slowly decrease and the world will eventually stabilize at a level that no one will be content with.
A return to high hopes for the future requires many nuclear power plants. But first something must be done about the poor leadership which got us to this shitfest.