The Montreal Protocol on Substances that Deplete the Ozone Layer

The Montreal Protocol on Substances that Deplete the Ozone Layer is a global agreement to protect the Earth’s ozone layer by phasing out the chemicals that deplete it. This phase-out plan includes both the production and consumption of ozone-depleting substances. The landmark agreement was signed in 1987 and entered into force in 1989.

The parties to the Protocol meet once a year to make decisions aimed at ensuring the successful implementation of the agreement. These include adjusting or amending the Protocol, which has been done six times since its creation. The most recent amendment, the Kigali Amendment, called for the phase-down of hydrofluorocarbons (HFCs) in 2016. These HFCs were used as replacements for a batch of ozone-depleting substances eliminated by the original Montreal Protocol. Although they do not deplete the ozone layer, they are known to be powerful greenhouse gases and, thus, contributors to climate change.

The Montreal Protocol provided a set of practical, actionable tasks that were universally agreed on. The Protocol has successfully met its objectives thus far and continues to safeguard the ozone layer today. Thanks to the collaborative effort of nations around the world, the ozone layer is well on its way to recovery.

Decision XXIII/9: Additional information on alternatives to ozone‑depleting substances

To request the Technology and Economic Assessment Panel to prepare a report in consultation with the other scientific experts, if necessary, for consideration by the Open-ended Working Group at its thirty-second meeting containing information on, among other things:

  1. The cost of alternatives to hydrochlorofluorocarbons that are technically proven, economically viable and environmentally benign;
  2. Alternatives to hydrochlorofluorocarbons that are technically proven, economically viable, environmentally benign and suitable for use in high ambient temperatures, including how such temperatures may affect efficiency or other factors;
  3. Quantities and types of alternatives already and projected to be phased in as replacements for hydrochlorofluorocarbons, disaggregated by application, both in parties operating under paragraph 1 of Article 5 of the Montreal Protocol and parties not so operating;
  4. An assessment of the technical, economic and environmental feasibility of options in consultation with scientific experts;