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 XXXVI/3: Emissions of HFC-23

The Thirty-Sixth Meeting of the Parties,

Noting with appreciation the updated information on HFC-23 emissions submitted by the Technology and Economic Assessment Panel and the Scientific Assessment Panel to the Thirty-Sixth Meeting of the Parties to the Montreal Protocol on Substances that Deplete the Ozone Layer in response to decision XXXV/7,[1]

Noting with concern that measured atmospheric abundances of HFC-23 continue to be substantially higher than the amounts expected on the basis of reporting by parties as set out in the report of the Scientific Assessment Panel prepared in response to decision XXXV/7,

Recalling the obligations provided for under Article 2J of the Montreal Protocol to ensure that HFC-23 emissions from relevant production facilities are destroyed to the extent practicable using technologies approved by the parties,

Decides:

  1. To invite relevant parties to undertake, as appropriate, and to encourage scientific institutes to undertake or cooperate with other institutions in undertaking, atmospheric monitoring of HFC-23 and research on sources of HFC-23 emissions and to share the results with the scientific community;
  2. To encourage parties to study the potential reasons for differences between reported emissions and emission estimates derived from atmospheric monitoring and submit relevant information to the Ozone Secretariat, when available and as appropriate;
  3. To invite parties that have HCFC-22 production facilities to submit to the Ozone Secretariat, on a voluntary basis, by 31 March 2025, their current methodologies for estimating and reporting of HFC-23 emissions from HCFC-22 production;
  4. To also invite parties that have adopted best practice technologies to reduce HFC-23 emissions to provide information thereon to the Ozone Secretariat, on a voluntary basis, by 31 March 2025;
  5. To request the Scientific Assessment Panel and the Technology and Economic Assessment Panel to update their decision XXXV/7 reports on HFC-23 to reflect any additional or new information that becomes available, and to submit their reports on the matter to the Thirty‑Seventh Meeting of the Parties to the Montreal Protocol on Substances that Deplete the Ozone Layer;
  6. To also request the Technology and Economic Assessment Panel to provide information on and a comparison of best practices and guidelines relating to measuring, estimating, reporting and verifying HFC-23 by-product emissions and their destruction.

 

[1] United Nations Environment Programme, Report of the Technology and Economic Assessment Panel: Response to Decision XXXV/7 – Emissions of HFC-23, vol. 5, Sept. 2024; United Nations Environment Programme, Report of the Scientific Assessment Panel: response to decision XXXV/7 – Emissions of HFC-23, Sept. 2024.