More importantly, he also provides alternatives to turning it on.
Cox notes that the improvement in a/c technology has been overcome by increase in home size and switching from room to central a/c, thus more energy is being used. [See Planetizen: "the efficiency paradox".]
In response to a question by Marketplace's Kai Ryssdal, Cox notes how a/c has affected community life:
"(O)one of the chief reasons I wrote the book was the ill ease I felt in going through neighborhoods that I knew had once been very lively places in the summer and then turned into dead zones. You would not see any human life out there, and the only sound would be the compressors and fans on the air conditioners. And I really do believe that what has been called by one author >"nature deficit disorder" is a problem that has been facilitated by air conditioning.