By Penelope Green

Modernity was born 116 years, 11 months, two weeks and two days ago, at a printing plant in the East Williamsburg section of Brooklyn, when a junior engineer named Willis Carrier devised a contraption that blew air over water-filled pipes to dry out the humidity that was gumming up the pages of a humor magazine called Judge.

And in that moment (well, within a few decades), entire industries and geographies were transformed, and new technologies made possible, including, terribly, the internet: Without cooling, there would be no server farms.

Nearly 90 percent of American households now have some form of air-conditioning, more than any other country in the world except Japan, though that will change as global warming alters more temperate zones, and swelling populations and rising incomes in hot zones mean the folks there will clamor for AC, too.