Between Earth and Sky

Chlorofluorocarbons, better known as CFCs, have had majortechnological applications since 1928. As refrigerants, they havebeen essential in the evolution of air conditioning andrefrigeration into common household technologies, and hence thetransformation of the lifestyle of the entire American South. CFCshave also been used as propellants in aerosol spray cans, in themanufacture of Styrofoam, and as industrial solvents. In 1974,however, two scientists discovered that these chemicals, previouslythought to be entirely safe, were eroding the ozone layer in theatmosphere, thus exposing the earth’s surface to deadly ultravioletlight and threatening the very existence of life on earth.

The core of this book is the history of CFCtechnology—its discovery, application, and eventualsubjection to international restrictions. The participants includeinventors, scientists, environmentalists, businessmen, and federalgovernment administrators. However, Cagin and Dray go beyondsimply telling the story of one technology. Instead, they use CFCsto discuss two broader issues. One is the how society handlesunintended negative consequences of technological progress. Supersonic transports, DDT, Storm King Mountain, and leaded gas areadditional examples which the authors bring up. The second issueis how much scientific evidence is necessary before the politicalsystem is willing to recognize that a threat to the environmentexists. In the case of CFCs, the industry argued that as long asscientists debated the data and its proper interpretation, thefederal government should not take action which would have anadverse economic impact. The authors ask: can the human raceafford to wait until all scientists agree?

This is a balanced account, written by nonscientists for layreaders.