The Montreal Protocol phases out ozone-depleting substances and its Kigali Amendment phases down HFCs

Background

The Ozone Secretariat of the UN Environment Programme describes the Montreal Protocol on Substances that Deplete the Ozone Layer as a global agreement to protect the Earth's ozone layer by phasing out the chemicals that deplete it.
The phase-out plan covers both the production and the consumption of ozone-depleting substances.
The agreement was signed in 1987 and entered into force in 1989.
The parties to the Protocol meet once a year to take decisions on its implementation, and the Protocol has been adjusted or amended six times since its creation.
The most recent amendment, the Kigali Amendment, called for the phase-down of hydrofluorocarbons, or HFCs.
HFCs were used as replacements for ozone-depleting substances that the original Protocol eliminated; they do not deplete the ozone layer but are powerful greenhouse gases and so contribute to climate change.
The Ozone Secretariat records that the Protocol has met its objectives so far and that the ozone layer is well on its way to recovery.