The whole world was paying attention to the international meeting prompted by an alarming finding fourteen years previously, that chlorofluorocarbon (CFC) chemical emitted by human activity break down the Earth’s ozone layer and increase the amount of ultraviolet radiation reaching the surface. Already a sizable hole was found above the Arctic, and unless concerted corrective steps would be taken soon, the fear was the danger would only increase.

On this day, September 16, in 1987 24 countries and the European Economic Community signed the Montreal Protocol on Substances that Deplete the Ozone Layer, agreeing to phase out use of CFC chemicals.

The United Nations was not officially involved in the discussions but its Secretary General Kofi Annan judged it to be “Perhaps the single most successful international agreement to date,” further stressing the importance of the agreement. But an alliance of industries most affected by the CFC regulations argued against the protocol implementation. DuPont, the American chemical conglomerate, testified in Congress “we believe that there is no immediate crisis that demands unilateral regulation.”