What’s certainly indefensible is our current habit of converting homes, offices and massive commercial outlets into igloos on all summer days, regardless of how hot it is outdoors. Recently, New York City prohibited stores from pumping arctic air out to the searing sidewalks, luring in customers but burning through fossil fuels in suicidal fashion. I can’t help but wonder whether someday cities like New York will prohibit stores from cooling their facilities below, say, 70°F. No doubt a law like that would raise even more objections than Mayor Michael Bloomberg’s attempt to ban big sodas, but it might well be necessary if we can’t turn down the dial on our own.

I’m skeptical that American businesses and consumers will reduce their use of air-conditioning without some new rules and regulations, especially now that natural gas has helped bring down energy bills and the short-term costs of cranking the AC are relatively low. Part of the problem is that in recent decades the fastest growing U.S. cities — places like Las Vegas, Phoenix and Austin — have effectively been built on air-conditioning. (This is also true in the Middle East and Asia, and as a result, global energy consumption is soaring precisely when it needs to come down.) Throughout the country, most designs for new office, commercial and residential property rely entirely on AC, rather than on time-honored cooling technologies such as shading from trees and cross-ventilation from windows and fans. As a result, there is now an expectation that indoor air will be frigid on even the steamiest days everywhere from the Deep South to the Great West. What’s worse, this expectation is also spreading to all the nations where American culture carries influence — sales of air conditioners rose 20% in India and China last year.