The same year that Chapman lectured on his theories about the ozone layer, a Swiss balloonist named Auguste Piccard ushered in a new public fascination with the stratosphere by being the first person to visit it himself, defying experts who had said it coldn't be done. Overnight, the stratosphere came to be seen as the likely new frontier for science and aviation. Journalists wrote of its weatherless serenity in AWED TONES, and of the mysterious ozone layer there that somehow protected us from the deadly rays of the sun.

Meanwhile, blissfully ignorant of the dangers CFCs might pose in the stratosphere, entrepreneurs were busy finding numerous uses for the miracle compound besides refrigeration. During the early months of World War II, malaria felled thousands of U.S. solders fighting in South Pacific jungles. The Army desperately sought a way to dispense insecticide over large areas to kill malarial mosquitoes. Agricultural researchers responded by inventing the aerosol spray dispenser, which used CFCs as a propellant. Joined in the cannister with another soon-to-be-infamous compound, DDT, the "Bug Bomb" proved highly effective. So much so that, after the war, ex-GIs who had seen the Bomb in action in the Pacific eagerly bought up all the Army's surplus for use in their own suburban backyards. DDT and CFCs together were so lethal that one bug spray manufacturer offered a $25,000 reward to anyone who could produce an insect capable of crawling away from a dousing.

With the success of the Bug Bomb, the aerosol spray industry was born. Aerosol manufacturers found that although products cost more when packaged in aerosol cans, people simply liked the convenience of spraying. CFC-powered aerosols for everything from insecticide to oven cleaner to decorative Christmas snowflakes were soon thriving in the "PUSH-BUTTON AGE" of the 50s.

Stability had always been CFCs' appeal: the molecule's constituent atoms of chlorine, fluorine, and carbon don't break down under normal or even extreme conditions, when hot, cold, dry or wet. In the home, that means no poisonous refrigerator leaks. In the atmosphere, it means that CFCs linger for up to 150 years--and can be used for studying the air motions of the lower atmosphere, as scientists began doing in the early 70s.

Then in 1974, F. Sherwood Rowland and his assistant Mario Molina, chemists at the University of California at Irvine, asked a question no one else had: what becomes of all these CFCs floating around in the atmosphere? They THEORIZED that CFCs might break apart when exposed to short waves of ultraviolet light, such as are found only in the stratosphere. And they made an alarming discovery: chlorine released by dissolving CFCs enters into a catalytic chain reaction with unstable ozone, one chlorine atom destroying thousands of ozone molecules and allowing HARMFUL UV RAYS to reach the earth.

Rowland and Molina were not the first scientists to suggest that human activities might harm the ozone layer. In 1971, an Arizona physicist named JAMES MACDONALD was concerned about ozone when he weighed in on the national debate over the U.S. funding of the Supersonic Transport (SST). The stratosphere- flying passenger plane, once expected to revolutionize air travel, was being resisted because of its cost and its noisy sonic booms. MacDonald introduced a new problem: water vapor from SST exhaust might erode stratospheric ozone. He foresaw a rise in skin cancer and the disruption of fragile ecosystems.