The story of one greenhouse gas, chlorofluorocarbons (CFCs, marketed by DuPont as Freon), offers a glimpse into what may lie ahead in the effort to reduce the emissions that cause global warming. Long used in refrigeration, air conditioning, aerosol sprays, and foam hamburger cartons, CFCs are now infamous for their DEPLETION of the earth's ozone shield. In the years between 1928 (when Thomas Midgley, Jr. and Charles Kettering invented this "Miracle Compound") and 1974 (when chemists F. SHERWOOD ROWLAND AND MARIO MOLINA brought the compound's dangers to worldwide attention), there lies a tale of clever scientists, foolish humans, and-- perhaps-- fatally damaged nature.

Charles "Boss Ket" Kettering, inventor of the first electric automobile ignition system, was vice-president of the General Motors Research Corporation in Dayton, Ohio from 1920 to 1948. Dayton, home of the Wright Brothers, was a mecca of American technological enthusiasm--the Silicon Valley of the early 20th century. Between 1885 and 1905, the CASH REGISTER, the airplane, automobile ignition, and consumer goods ranging from carriage springs to folding ice cream boxes were invented and manufactured there.

Back then, household refrigeration was not much more than an idea. All the commonly used REFRIGERANTS--ammonia, sulphur dioxide and methyl chloride--were dangerous. They were either flammable, toxic, or both. In Cook County, Illinois, between August 1928 and July 1929 alone, the coroner reported no fewer than 29 deaths from methyl chloride poisoning related to refrigeration leaks. Kettering, who believed ardently in the future of household refrigeration, was dismayed to learn that many owners of GM Frigidaires were keeping them out on the porch, for safety's sake.

To solve the refrigerant problem, Kettering turned to his protege, GM's star research scientist, THOMAS MIDGLEY JR., an eccentric but brilliant young man who had invented one of the other great environmental villains of the 20th century: leaded gasoline, or ethyl.

Unlike CFCs, whose environmental threat would not be understood for decades, lead in gasoline was controversial from the moment it was introduced. People had known for centuries that lead has toxic properties. In the 1920s, several workers had died suddeny at plants where tetraethyl lead (TEL) was manufactured for use as a gasoline additive. Other victims of lead poisoning became delusional or manic, or suffered serious nervous disorders; some went mad and tried to take their own lives.