About
Delegates committed firmly to address threats to both the ozone layer and the global climate, designating a significant portion of the replenishment of the Multilateral Fund to the implementation of the Kigali Amendment, which will phase out hydrofluorocarbons (HFCs) and bring down global temperatures.
Final report
Summary report 22–27 October 2023
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In 1987, the world made history by adopting the Montreal Protocol on Substances that Deplete the Ozone Layer, taking the first step in healing the Earth’s protective ozone layer. The Protocol came into effect in 1989 and now has universal ratification. Initially the Protocol mainly controlled chlorofluorocarbons (CFCs) and halons but was quickly amended to include hydrochlorofluorocarbons (HCFCs) along with other ozone depleting substances. Over the years, the Protocol has been recognized as the most successful multilateral environmental agreement, and not without cause.
Ozone layer depletion causes increased ultraviolet (UV) radiation levels at the Earth's surface, which is damaging to human health and the environment. Negative effects to human health include increases in certain types of skin cancers, eye cataracts and immune deficiency disorders. UV radiation also affects terrestrial and aquatic ecosystems, altering growth, food chains and biochemical cycles. Aquatic life just below the water’s surface—the basis of the food chain—is particularly adversely affected by high UV levels. UV rays also affect plant growth, reducing agricultural productivity.
The fruits of concerted efforts to curb ozone-depleting substances are paying off, as studies show that the ozone layer is healing. In recent years, the Montreal Protocol has been amended to take on additional challenges related to the production and consumption of climate-altering hydrofluorocarbons (HFCs). These chemicals initially served as replacements for CFCs and HCFCs, but while they are not as damaging to the ozone layer, they are potent greenhouse gases.
But much remains to be done to ensure the continued success of the Protocol.
The thirty fifth Meeting of the Parties (MOP 35) considered and took decisions on a host of issues, including:
- Budget of the Trust Fund for the Montreal Protocol and financial reports;
- Replenishment of the Multilateral Fund (MLF) for the Implementation of the Montreal Protocol for the triennium 2024-2026;
- Stratospheric aerosol injection and protection of the ozone layer, which is an emerging issue;
- Whether and how to address very short-lived substances, including dichloromethane;
- A proposed adjustment to the Protocol regarding the potential impacts of the COVID-19 pandemic on HFC consumption for developing countries;
- Shared responsibility to stop dumping inefficient equipment containing obsolete refrigerants;
- Future availability of halons and their alternatives;
- Strengthening Montreal Protocol institutions, including for combating illegal trade;
- Recommendations of the Implementation Committee under the Non-Compliance Procedure for the Montreal Protocol; and
- Reclassification of developing countries.
Delegates met at the headquarters of the United Nations Environment Programme (UNEP) in Nairobi, Kenya from 23-27 October 2023. MOP 35 was preceded by a workshop on energy-efficient and low- or zero-global-warming-potential technologies, which was held on Sunday, 22 October 2023.
The Earth Negotiations Bulletin (ENB) writers for this meeting were Tallash Kantai; Wanja Nyingi, Ph.D.; Jose F. Pinto-Bazurco, Ph.D.; and Kaspar Sollberger, Ph.D. The Digital Editor was Mike Muzurakis. The Editor was Pam Chasek, Ph.D.
View past and future events
Past event
Vienna Convention COP 5 and Montreal Protocol MOP 11
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20th Meeting of the Open-Ended Working Group of the Parties to the Montreal Protocol
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Montreal Protocol MOP 12
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Montreal Protocol MOP 13
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22nd Meeting of the Open-Ended Working Group of the Parties to the Montreal Protocol
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Vienna Convention COP 6 and Montreal Protocol MOP 14
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Montreal Protocol MOP 15
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1st Extraordinary Meeting of the Parties to the Montreal Protocol (ExMOP-1)
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Montreal Protocol MOP 16
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25th Meeting of the Open-ended Working Group of the Parties and 2nd Extraordinary Meeting of the Parties to the Montreal Protocol (ExMOP-2)
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Vienna Convention COP 7 and Montreal Protocol MOP 17
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26th Meeting of the Open-Ended Working Group of the Parties to the Montreal Protocol
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Montreal Protocol MOP 18
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Montreal Protocol MOP 19
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Viena Convention COP 8 and Montreal Protocol MOP 20
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29th Meeting of the Open-Ended Working Group of the Parties to the Montreal Protocol
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Montreal Protocol MOP 21
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Montreal Protocol MOP 22
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31st Meeting of the Open-Ended Working Group of the Parties to the Montreal Protocol
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Vienna Convention COP 9 and Montreal Protocol MOP 23
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32nd Meeting of the Open-Ended Working Group of the Parties to the Montreal Protocol
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Montreal Protocol MOP 24
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33rd Meeting of the Open-Ended Working Group of the Parties to the Montreal Protocol
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Montreal Protocol MOP 25
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34th Meeting of the Open-Ended Working Group of the Parties to the Montreal Protocol
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Vienna Convention COP 10 and Montreal Protocol MOP 26
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Workshop on Hydrofluorocarbon Management and 35th Meeting of the Open-ended Working Group of the Parties to the Montreal Protocol
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36th Meeting of the Open-Ended Working Group of the Parties to the Montreal Protocol
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Resumed 36th Meeting of the Open-ended Working Group of the Parties to the Montreal Protocol
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Montreal Protocol MOP 27
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37th Meeting of the Open-Ended Working Group of the Parties to the Montreal Protocol
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3rd Extraordinary Meeting of the Parties to the Montreal Protocol (ExMOP 3) and Associated Meetings
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Montreal Protocol MOP 28
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39th Meeting of the Open-Ended Working Group of the Parties to the Montreal Protocol
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Vienna Convention COP 11 and Montreal Protocol MOP 29
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Workshop on Energy Efficiency Opportunities While Phasing-Down Hydrofluorocarbons (HFCs) and 40th Meeting of the Open-Ended Working Group of the Parties to the Montreal Protocol on Substances that Deplete the Ozone Layer
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30th Meeting of the Parties to the Montreal Protocol on Substances that Deplete the Ozone Layer
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41st Meeting of the Open-Ended Working Group of the Parties to the Montreal Protocol on Substances that Deplete the Ozone Layer (OEWG 41)
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31st Meeting of the Parties to the Montreal Protocol on Substances that Deplete the Ozone Layer (MOP 31)
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42nd Meeting of the Open-ended Working Group of the Parties to the Montreal Protocol on Substances that Deplete the Ozone Layer (OEWG 42)
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12th Meeting of the Conference of the Parties to the Vienna Convention (Part I) and 32nd Meeting of the Parties to the Montreal Protocol
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4th Extraordinary Meeting of the Parties to the Montreal Protocol (ExMOP-4) and 1st Part of the 43rd Meeting of the Open-ended Working Group (OEWG43)
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2nd Part of the 43rd Meeting of the Open-ended Working Group of the Parties to the Montreal Protocol (OEWG 43)
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Combined 12th Meeting of the Conference of the Parties to the Vienna Convention (Part II) and 33rd Meeting of the Parties to the Montreal Protocol
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44th Meeting of the Open-ended Working Group of the Parties to the Montreal Protocol (OEWG-44) and 5th Extraordinary Meeting of the Parties to the Montreal Protocol (ExMOP-5)
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34th Meeting of the Parties to the Montreal Protocol on Substances that Deplete the Ozone Layer (MOP34)
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45th Meeting of the Open-ended Working Group of the Parties to the Montreal Protocol
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35th Meeting of the Parties to the Montreal Protocol on Substances that Deplete the Ozone Layer (MOP35)
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