Scientific discoveries, national regulations, and international agreements impact our lives. If we bring all three together in a solid but flexible governance structure, then we are able to address those impacts and share more evenly their consequences across different nations. This is what the Montreal Protocol has done in its 30 years of life and will continue to do thanks to the recent Kigali Amendment. There are many lessons for diplomacy to be drawn from the recent negotiations, including the critical role of science. The most important lesson in reaching consensus is the injection of optimism, pride, ownership of the process, and building trust among all nations. The solid yet flexible foundation of the Montreal Protocol provided a firm grounding for the Kigali negotiations to experiment with the different negotiating techniques in a forum where countries, industry, non-governmental organizations, and scientists are brought together by the United Nations.

Anniversaries apart from celebration provide an opportunity to reflect on what worked, what can change and what can be replicated to different settings. Thirty-one years after the Montreal Protocol was adopted, there are many achievements of which nations can be collectively proud. Its significance lies on three main points: first, united action and universal membership of 197 parties to the ozone treaties to achieve results; second, right science and an agreement on finance and technology to reconcile the nations’ different needs and act as one on a global challenge; third, patience for thirty years to see the positive results of the concerted actions, a time scale that needs to be factored in, in international negotiations.

The success of this environmental regime is based on the interaction between science, policy, and diplomacy. Scientific discoveries, national regulations, international agreements, they all have an impact on the people's lives. If all three are brought together in a solid but flexible governance structure, then the impacts on people's lives can be shared more evenly across different nations.

This is exactly what the Montreal Protocol has done in its thirty-one years of life and will continue to do in the thirty years ahead thanks to the recent adoption of the Kigali Amendment.

The Secretariat of the Vienna Convention for the Protection of the Ozone Layer and the Montreal Protocol on Substances that Deplete the Ozone Layer (Ozone Secretariat) is responsible for servicing the meetings of these two treaties and ensuring the parties have all the necessary information they need to take decisions. The Secretariat is also following up on those decisions and supports their implementation. The Secretariat therefore has an important role to play in facilitating the negotiations among the parties to the Montreal Protocol, who now number 197. One of the indicators of success of the Ozone Treaties, and the seriousness with which the parties regard the problem, is the fact that both the Convention and the Protocol have achieved universal ratification, a distinction that is rarely achieved in international agreements.

This article is divided in five sections:

•Benefits today arising from the Montreal Protocol;
•Governance structure of the Montreal Protocol;
•Phasing down HFCs under the Kigali Amendment;
•Reflections on a new diplomacy based on the recent experience of the Kigali Amendment;
•Concluding remarks.