Thirty-five years ago, the adoption of the Montreal Protocol on Substances that Deplete the Ozone Layer marked a turning point in environmental history. When scientists discovered that man-made chemicals used in aerosol sprays and coolants were depleting the earth’s protective ozone layer, potentially exposing millions to dangerous ultraviolet radiation, governments took action.

On 16 September 1987, governments adopted the Montreal Protocol to control and reduce ozone-depleting substances, mainly chlorofluorocarbons (CFCs) and halons. The Protocol came into effect in 1989. By 2008, it was the first and only United Nations environmental agreement to have universal ratification. Over the years, more ozone-depleting substances have been phased out and the ozone layer is healing. Yet there is more work to be done.

When delegates to the Thirty-Fourth Meeting of the Montreal Protocol (MOP34) convened in late October, they had a full agenda, with work ranging from technical issues related to the Convention’s work to protect the ozone layer from harmful substances to essential budgetary matters. MOP34 built on the deliberations of the Forty-Fourth Meeting of the Open-ended Working Group (OEWG44), which was held in July 2022.

Parties tackled a lengthy list of substantive issues, including, but not limited to, work on:

• energy efficiency; 
• identification of gaps in global coverage of atmospheric monitoring of controlled substances;
• ongoing emissions of carbon tetrachloride;
• the future availability of halons and their alternatives;
• implementation of the Kigali Amendment to phase down hydrofluorocarbons; and
• institutional processes to strengthen the effective implementation and enforcement of the Montreal Protocol.

During the preparatory segment (31 October -2 November), delegates addressed crucial administrative matters, including the 2023 budget of the Montreal Protocol and the financial reports for the trust funds for the Vienna Convention for the Protection of the Ozone Layer and the Montreal Protocol. Parties also considered the membership of key bodies, including: the Implementation Committee, which receives, considers, and reports on issues of non-compliance with the Montreal Protocol; the Executive Committee of the Multilateral Fund, which oversees the operation of the Fund; and the Co-Chairs of the OEWG, which prepares for the MOP.   

During the high-level segment (3-4 November), the Co-Chairs of the three assessment panels reported on their work and highlight any key issues from their quadrennial assessments to be completed by the end of 2022. The assessment panels, which include the Technology and Economic Assessment Panel, the Scientific Assessment Panel, and the Environmental Effects Assessment Panel, provided scientific, technological and financial information to help parties take decisions about ozone layer protection.

Additionally, delegates heard a presentation by the Chair of the Executive Committee of the Multilateral Fund, the Multilateral Fund Secretariat, and the Fund’s implementation agencies. Heads of delegations made statements and delegates considered decisions recommended for adoption.

MOP34 was held at the International Civil Aviation Organization Conference Centre in Montreal, Canada, 31 October – 4 November 2022.