Measures to Save Ozone Stemmed a Lot More Global Warming - [Junk] ScienceNOW

SAN FRANCISCO, CALIFORNIA—Now, for a change, some good news on the environmental front. Global efforts launched in 1989 to stem emissions of chlorofluorocarbons (CFCs)—volatile chemicals, used as refrigerants and propellants in spray cans, that break down ozone—have borne fruit not only by protecting ozone in the atmosphere but also by preventing even more dramatic atmospheric heating. That's because, like carbon dioxide, CFCs in the atmosphere trap heat. New studies, presented here last month at the fall meeting of the American Geophysical Union, show that had humanity not cut this pollution, Earth would have experienced as much as 1.5ºC of additional global warming by 2070. Moreover, the new projections show, CFC pollution would have thinned the layer of ozone in the upper atmosphere, which blocks harmful ultraviolet radiation, even more than scientists expected, as a result of an unforeseen "feedback" effect.