Nations Agree to Protect the Ozone Layer

On 16 September 1987, diplomats from around the world finalized the Montreal Protocol on Substances That Deplete the Ozone Layer. This landmark international treaty was designed to safeguard the atmosphere by curbing and eventually eliminating the manufacture of industrial chemicals that degrade stratospheric ozone. Entering into force on 1 January 1989, the accord represented a decisive shift from scientific inquiry into coordinated global governance.

The roots of the convention traced back to 1974, when chemists Frank Sherwood Rowland and Mario Molina demonstrated that chlorofluorocarbons could travel into the stratosphere, release chlorine under ultraviolet radiation, and destroy significant volumes of ozone. In 1985, British Antarctic Survey scientists documented severe atmospheric thinning near the South Pole. Satellite visualizations and the revelation that scientists report a hole in the ozone layer created widespread urgency among governments, building rapid momentum to move beyond the non-binding framework of the 1985 Vienna Convention.