Despite the fact we are in a pandemic w/ financial consequences big & small , climate change is the unavoidable problem lurking in the background.This book was like taking a class(in a good way)Diamond shows historical & contemporary examples of how humans adapt, change, conserve,or perish.With a record 35 days this summer over 110 & no end in sight , a new record here in Phoenix ,Az.What is sustainable?What is not? A thought provoking read.