Press Release: World Ozone Day 2026: Global action for a cooler planet

Every year on 16 September, World Ozone Day commemorates the 1987 Montreal Protocol on Substances that Deplete the Ozone Layer, ultimately signed by every country in the world. This protocol is crucial to control the production and use of ozone depleting substances (ODSs) such as chlorofluorocarbons (CFCs) and other substances that replaced CFCs.

Press Release: The International Ozone Commission, on the 38th anniversary of the Montreal Protocol, underscores the success of the protocol, and stresses the value of continued observations, modeling, and research.

The 38th International Day for the Preservation of the Ozone Layer, September 16, 2025, marks the anniversary of the signing of the 1987 Montreal Protocol on Substances that Deplete the Ozone Layer. This protocol, a treaty signed by every country in the world and hailed as among the most successful international agreements to date, controls the production and use of ozone depleting substances (ODSs) such as chlorofluorocarbons (CFCs) and the other substances used as initial CFC replacements. As a result of the actions taken worldwide in response to the protocol and its amendments and adjustments, atmospheric abundances of ODSs are declining, and the stratospheric ozone layer, which shields life on Earth from harmful solar ultraviolet radiation, is showing clear signs of recovery.

Press Release: The International Ozone Commission, on the 37th anniversary of the Montreal Protocol, reports successes, developments, and future challenges in monitoring ozone layer recovery

September 16th is the International Day for the Preservation of the Ozone Layer, celebrating the signing anniversary of the 1987 Montreal Protocol on Substances that Deplete the Ozone Layer. The Montreal Protocol is the treaty, ratified by every country in the world, that controls the production and use of ozone depleting substances (ODSs) such as chlorofluorocarbons (CFCs) and their early replacements. As a result of the Protocol, ODSs are declining and the ozone layer, including the Antarctic ozone hole, is showing signs of recovery, ensuring continued protection of life on Earth from harmful solar ultraviolet radiation. Nevertheless, the future evolution of surface solar ultraviolet radiation has important uncertainties caused by the expected changes in our climate.