Adopted at Montreal and amended at Kigali: the treaty that protects the ozone layer

Background

The Montreal Protocol on Substances that Deplete the Ozone Layer was adopted on 16 September 1987 and is one of very few treaties to have reached universal ratification. It works by phasing out the production and use of chemicals that thin the ozone layer in the stratosphere, which shields life on earth from ultraviolet radiation. Under the Kigali Amendment, countries agreed to add hydrofluorocarbons to the list of controlled substances; hydrofluorocarbons do not harm ozone but are powerful greenhouse gases used in refrigeration and air conditioning. The Kigali Amendment came into force on 1 January 2019 for the countries that had ratified it. The anniversary of the adoption, 16 September, is observed each year as World Ozone Day. India is a party to the Protocol and to the Kigali Amendment.