March 1982 | The NAS releases a third report on CFC-ozone and predicts eventual ozone depletion of 5 to 9 percent. |
February 1984 | A fourth NAS report downplays the potential harm to the ozone layer from CFCs by lowering depletion estimates to 2 to 4 percent. |
October 1984 | A British research group led by Joe Farman detects a 40 percent ozone loss over Antarctica during austral spring. |
March 1985 | The Vienna Convention, calling for additional research and exchange of information on ozone depletion, is signed by international negotiators. Negotiators fail to agree on worldwide CFC regulations. |
May 1985 | Farman's paper is published in Nature. |
August 1985 | NASA's Heath shows satellite photos confirming the existence of an ozone hole over Antarctica. |
January 1986 | EPA releases its Stratospheric Ozone Protection Plan which calls for new studies to determine whether additional CFC regulations are needed. |
June 1986 | Papers are published by two research groups indicating chemicals and polar stratospheric clouds are responsible for ozone losses over Antarctica. |
June 1986 | CFC manufacturers suggest that safe substitutes for the chemicals might be possible for a high enough price. |
September 1986 | A major CFC industry lobbying group announces it will support limits on CFC growth. |
September 1986 | The DuPont Corporation announces it will call for limits on world-wide CFC production. |
December 1986 | International negotiations on ozone protection resume in Geneva after a 17 month layoff. The United States proposes worldwide CFC reduction of 95 percent by the next decade. |
April 1987 | Under pressure from some high-level officials, the United States backs off its original position and proposes long-term CFC reductions of 50 percent. |
June 1987 | NASA's Heath reports satellite findings of a 4 percent ozone loss detected over a seven year period. A NASA-sponsored study called the Ozone Trends Panel is organized to review the findings. |
August 1987 | The McDonald Corporation announces it will no longer purchase materials which were made using CFCs to package its food products. |