[ahevia]

Drought has always been part of the American west. The distinction here is the frequency & intensity of # of drought days. Those are increasing due to us pumping GHG into our atmosphere.

The ecosystem in the west has adapted to drought, but they never adapted for a sudden increase in drought in only a few decades (not long enough for evolution to create useful adaptations on a large scale to speciate) + a competing species reducing total avail land and taking up water supply.