Science panel event

In 2025 the Vienna Convention for the Protection of the Ozone Layer celebrated 40 years since its adoption. In 1985, acknowledging that there was sufficient scientific information supporting a hypothesis that man-made chlorofluorocarbons (CFCs) were potentially destroying the ozone layer, the world came together and agreed that a solution need to be found. The Vienna Convention laid the foundations for the Montreal Protocol on Substances that Deplete the Ozone Layer which was adopted only 2 years later and has set the ozone layer on a path of recovery. 

To celebrate the 40th anniversary of this incredibly important ozone treaty, the Ozone Secretariat created a documentary charting the history, achievements and the work that continues to this day. It was screened at a special event during the Thirty-Seventh Meeting of the Parties to the Montreal Protocol held in Nairobi from 3-7 November 2025. 

The session was opened with a reflection on the historical significance of the Vienna Convention for the Protection of the Ozone Layer by Stephen O. Andersen, Director of Research at the Institute for Governance & Sustainable Development (IGSD). A member of the Montreal Protocol community since its adoption in 1987, he served as Founding Co-Chair of the Technology and Economic Assessment Panel (1989–2012) and held leadership roles at the U.S. Environmental Protection Agency (1986–2009). 

He reminded the audience of key milestones:

• 1974: Mario J. Molina and F. Sherwood Rowland warned that CFCs destroy stratospheric ozone.
• 1975: Veerabhadran Ramanathan highlighted that CFCs are powerful greenhouse gases.
• 1985: The Vienna Convention was agreed upon.
• 5 weeks later, Joseph Farman and colleagues from the British Antarctic Survey revealed the discovery of a massive ozone hole.

The audience was then invited to watch the documentary available here which was followed by a science panel discussion featuring current members of the Scientific Assessment Panel:

• Prof. Lucy Carpenter, University of York, UK – Co-Chair, Montreal Protocol Scientific Assessment Panel
• Dr. Kenneth Jucks, NASA – Co-Chair, Montreal Protocol Scientific Assessment Panel
• Dr. Stefan Reimann, Empa, Switzerland – Chapter Lead Author

Stephen Andersen initiated the discussion followed by his reflections on the film and in turn asking each panelist to share what inspired them most from the film:

• Stephen: “I was most inspired by the courage of scientists in bringing forward new environmental warnings and the public appreciation for science done right and on time.”
• Lucy: “I was very inspired by the passion and determination of the scientists to unravel the mechanisms responsible for ozone depletion and to look in great detail at what the data was telling them.”
• Ken: “I was taken by Jonathon Shanklin’s comments about questioning the veracity of their data. That’s what all good measurement scientists are supposed to do! And when the satellite people, who were doing the same thing, saw the BAS data, they felt more confident that their data were not an instrument artefact. This type of interaction between satellite and ground-based observations is now very commonplace for most areas of Earth Science observations.”
• Stefan: “I am seeing that the next generation is taking on the responsibility to progress with the science related to stratospheric ozone, climate change, and their interactions.”

The audience were then encouraged to ask the panel questions. These included:

“What do you perceived as the main opportunities, from a science perspective, for the Montreal Protocol looking ahead?”

“How do scientists manage to remain objective and not push their own agenda despite having their own firm ideas. Is that something the panel struggles with?”

To watch the entire science panel event including the screening of the documentary to mark the 40th anniversary of the Vienna Convention, click here.