International Stratospheric Ozone and F-Gas technical support

The Montreal Protocol on Substances that Deplete the Ozone Layer is an international treaty designed to protect the ozone layer by phasing out the production and consumption of substances that are responsible for ozone depletion.

The Kigali Amendment to the Montreal Protocol was adopted by the 28th Meeting of the Parties to the Montreal Protocol on 15 October 2016 in Kigali, Rwanda. It entered into force on 1 January 2019, after the threshold for the agreement to enter into force was met on 17 November 2017. Under the Amendment, all countries will gradually phase down climate-warming hydrofluorocarbons (HFCs), which are not ozone depleting substances (ODS) but are strong greenhouse gases, by more than 80 percent over the next 30 years and replace them with more climate-friendly alternatives.

Developed countries have started reducing HFCs since 2019, followed by developing countries who will start later. Phasing down HFCs under the Protocol is expected to avoid up to 0.5°C of global warming by the end of the century, while continuing to protect the ozone layer.

The phase down on HFCs requires development and uptake of suitable alternative refrigerants, which can substitute the HFCs in relevant equipment such as air conditioners or refrigeration equipment world-wide.