The Thirty-Seventh Meeting of the Parties to the Montreal Protocol (MOP37) took place in Nairobi, Kenya, from 3–7 November 2025, with sessions also streamed online. The meeting focused on advancing global efforts to protect the ozone layer and address climate-related challenges associated with substances controlled under the Protocol.
A priority was agreeing on the terms of reference for a study on the 2027–2029 replenishment of the Multilateral Fund (MLF) that will estimate the funds necessary to enable Article 5 parties (developing countries) to meet their obligations during that period. Parties stressed that the Technology and Economic Assessment Panel (TEAP) should consult widely and share calculation details. The study will, among others, address issues such as the HFC phase-down, the needs of low- and very-low-volume-consuming countries and include a scenario for funding pilot projects to improve regional atmospheric monitoring.
Delegates also received updates on HFC-23 emissions from the Scientific Assessment Panel (SAP) and the TEAP. These updates show that despite new data, significant gaps remain between reported and measured emissions, with no new sources identified since 2015. The Panels have been requested to provide updated information to the Thirty-Eighth Meeting of the Parties (MOP38) in November 2026, and parties have also been invited to provide further relevant information on HFC-23 emissions from HCFC-22 production. International collaboration on research into HFC-23 emissions and their sources is encouraged.
The Secretariat and the Advisory Committee of the Vienna Convention General Trust Fund reported on site evaluations, cost estimates, and financing options, for establishing and operating monitoring stations. Progress with identifying ten priority locations to fill major gaps in monitoring regional emissions. The Secretariat was asked to continue evaluating these sites and prepare for possible monitoring activities. Updates will be provided at OEWG48 and MOP38.
Other issues discussed included improving the end-of-life management of refrigerants in Article 5 countries. TEAP was asked to evaluate how much refrigerant gas is nearing the end of its life, what destruction and recycling facilities exist, and the potential ozone and climate benefits of reclaiming or destroying unwanted refrigerants.
Parties also addressed the continued use of halon 1301 in aviation, where there is concern due to the uncertainty of its long-term supply. They were invited to share information with the Ozone Secretariat on fire suppression alternatives to feed into TEAP’s 2027 report and help with information exchanges on the issue between TEAP and other aviation technical groups, including and in particular the relevant committees and technical working groups under International Civil Aviation Organization.
In relation to national and regional initiatives to support the implementation of the Kigali Amendment, parties were asked to provide information on centres of excellence for sustainable cooling and energy-efficiency to be collated into a background paper for MOP38.
Prior to MOP37, delegates gathered at an informal meeting on facilitating implementation of Montreal Protocol to explore, as reflected in the outcomes document, improving licensing systems, tackling illegal trade, strengthening data collection and report systems, and capacity enhancement. Discussions continued in plenary, drawing on the informal meeting but no decision could be agreed. Renewed proposal on some specific next steps may be tabled next year.
Other matters included assessing and ensuring the viability of Montreal Protocol operations under which the Secretariat has been requested to prepare a report, for consideration by OEWG48, on options for effective and efficient changes to the timing of meetings of Montreal Protocol bodies and the decisions on replenishment of the Multilateral Fund. Cost estimates and the pros and cons of the options should also be provided.
High-level segment
Assessment panels presented their progress reports, including on emerging issues. The SAP reported that chlorine and bromine levels are falling, but HFC) emissions in 2024 were higher than all ozone-depleting substances (ODSs) combined. They also reported increased production of ODSs for feedstock uses and new estimates of the potential impact of solar radiation management on the ozone layer. The Environmental Effects Assessment Panel (EEAP) highlighted concerns about stratospheric aerosol injection, per- and polyfluoroalkyl substances (PFAS) or ‘forever chemicals’, and the combined effects of ultraviolet radiation and climate change on health and ecosystems. TEAP reported progress in phasing out hydrochlorofluorocarbons (HCFCs) and HFCs in foams but noted challenges with some alternatives. They confirmed that substitutes for methyl bromide - an ODS - are now available for most pre-shipment uses.
The Implementation Committee reported on cases of non-compliance. For the first time, MOP37 suspended the rights and privileges related to trade in HCFCs between parties and the non-compliant party.
The high-level segment featured a performance by Ghetto Classics and a video address from Ms. Inger Andersen, Executive Director, United Nations Environment Programme (UNEP). She acknowledged that parties were meeting in turbulent times and urged them to “keep talking, keep listening and keep people and planet at the centre.”
Her Excellency, Ms. Deborah Mlongo Barasa, Cabinet Secretary, Ministry of Environment, Climate Change and Forestry of Kenya, noted with pride in her address that since ratifying the Kigali Amendment in 2023, Kenya has been playing its part supporting climate change mitigation.
On the sidelines, 23 side events were held, including a documentary screening and science panel discussion to mark the Vienna Convention’s 40th anniversary.
Despite challenges, the MOP37 achieved progress and adopted a total of 23 decisions to ensure continued Montreal Protocol long-term success. However, the parties could not agree on the full membership of the Implementation Committee, deferred to an Extraordinary Meeting next year.
NOTES TO EDITORS
About the Montreal Protocol
The Montreal Protocol is a global agreement to protect the Earth’s ozone layer by phasing out the chemicals that deplete it. The landmark agreement entered into force in 1989 and it is one of the most successful global environmental agreements. Thanks to the collaborative effort of nations around the world, the ozone layer is on its way to recovery and many environmental and economic benefits have been achieved.
About the UN Environment Programme
UNEP is the leading global voice on the environment. It provides leadership and encourages partnership in caring for the environment by inspiring, informing and enabling nations and peoples to improve their quality of life without compromising that of future generations.
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