Thats what happened to the Anasazi.
We’ve lost our thunderstorms.
When you lose thunderstorms (as we have) you lose nitrogen.
Weve lost our thunderstorms.
Rain occurs when the water vapor has something in the air to attach to. I submit that the unintended consequences (maybe its intended knowing the demons in D.C.) of obsessive clean air guidelines is to strip the air of any particles so that it rains less. The answer is for California to return to fouling the air, stirring up dust and burning down forests so that it will rain again over the South West