Healing the Ozone Layer: The Montreal Protocol

In 1974 chemists Mario Molina and F. Sherwood Rowland warned that chlorofluorocarbons (CFCs), used in refrigerators and aerosol sprays, could destroy the ozone layer, which shields life from harmful ultraviolet radiation. In 1985 British Antarctic Survey scientists Joseph Farman, Brian Gardiner and Jonathan Shanklin reported a dramatic seasonal thinning over Antarctica, the ozone hole.

Governments responded quickly: the Vienna Convention (1985) and the Montreal Protocol (1987) committed countries to phase out CFCs, with financial help for developing countries. In 2009 the Montreal Protocol became the first UN treaty ratified by every member state. Scientists project that the ozone layer over Antarctica should recover to 1980 levels around the 2060s. The 2016 Kigali Amendment extended the treaty to hydrofluorocarbons.

The ozone story is often cited as the most successful global environmental agreement, showing how science, industry and diplomacy can work together.