How did basic research help scientists discover the effects of ozone-depleting chemicals in Earth’s atmosphere? The video “Science Works: Protecting the Ozone Layer” from the Annenberg Public Policy Center tracks the history of this research. It’s a story that goes from observation of the sky by ancient Greek philosophers to investigative research into the chemical makeup of the atmosphere to concentrated efforts in the 1970s and 80s to determine the effects of chemicals used in aerosol spray cans for products like hair spray and deodorant, as well as in refrigerants and in manufacturing plastics.
The research and predictions made by scientists led to public policy changes to protect and eventually ban the chlorofluorocarbons (CFCs) that were destroying the ozone layer. That action was taken in the Montreal Protocol, an international treaty signed by the United States in 1987.
In 2014, scientists with NASA, the World Meteorological Organization and other groups projected that the ozone layer is on track to recover to its 1980 level by the middle of this century.