Suburbia’s original appeal came wrapped in visions of green earth, clear skies and backyard bliss. But to fulfill the dreams of home buyers on modest incomes, developers cut back on costly structural features such as movable window sashes, screens, awnings and eaves, high ceilings, thermal mass, cross-ventilated designs and attic fans. They bulldozed shade trees and began building instead for mechanical climate control. Families responded by spending more time indoors…

Running full blast, a car’s air conditioner dramatically increases levels of noxious exhaust in the surrounding air, guaranteeing that other drivers will have to keep their windows closed and the air running. In that, as in many other ways — by aggravating global warming, by encouraging poor building ventilation, by increasing our own biological susceptibility to heat — dependence on air conditioning always seems to generate demand for more air conditioning.

Air conditioning buildings and cars in the United States has the climate impact of half a billion metric tons of carbon dioxide a year. That exceeds the total annual carbon dioxide emissions of any one of these nations: Australia, France, Brazil or Indonesia. In an effort to reduce energy use and curb greenhouse emissions, industry and government are pursuing more efficient cooling technologies for cars and buildings. But greater efficiency can’t reverse the unsustainable living, working and transportation patterns that air conditioning has helped foster.