Painstaking research on ozone and the atmosphere over the past 40 years has led to a global ban on CFC production. Since 1987, more than 150 countries have signed an international agreement, the Montreal Protocol, which called for a phased reduction in the release of CFCs such that the yearly amount added to the atmosphere in 1999 would be half that of 1986. Modifications of that treaty called for a complete ban on CFCs which began in January 1996. Even with this ban in effect, chlorine from CFCs will continue to accumulate in the atmosphere for another decade. It may take until the middle of the next century for ozone levels in the Antarctic to return to 1970s levels.
More globally, ozone depletion is expected to remain a fact of life for several decades to come, but thanks to the research that led to early recognition of the problem and steps that have been taken to address it, the potential consequences are much less severe than they otherwise would have been.
Scientists estimate, for example, that if active research in stratospheric chemistry had not been in place at the time the ozone hole was discovered in 1985 and confirmed in 1986, global ozone depletion, measuring 4 percent today, would be close to 10 percent by the year 2000. Even larger ozone depletion would have been observed over the United States and Eastern Europe, substantially exceeding the current measurements there of about 10 percent loss in winter and spring and 5 percent in summer and autumn. These larger losses have been avoided because basic research in the atmospheric sciences had already advanced to a level where it was able to explain the chemical reactions occurring in the ozone layer. That knowledge allowed other informed political and regulatory decisions to be made
In 1995, the Royal Swedish Academy of Sciences awarded Rowland, Molina, and Crutzen the Nobel prize in chemistry for showing “how sensitive the ozone layer is to the influence of anthropogenic emissions of certain compounds.” In explaining the chemical mechanisms that affect the thickness of the ozone layer, “the three researchers have contributed to our salvation from a global environment problem that could have catastrophic consequences,” the academy noted.
As lawmakers and the public face new challenges in the struggle to protect the environment, they will increasingly rely on basic research to open new vistas and suggest new solutions about these pressing concerns.