How Do We Change What's Possible?: Global Efforts to Combat Climate Change

In this masterclass, we discussed the most successful international environmental treaty effort to date: the global efforts to reduce ozone-depleting substances. Over the past 35 years, the treaty and its amendments successfully controlled chemicals like CFCs, HCFCs, and HFCs to mitigate both ozone depletion and (recently) climate change. Although this treaty is extremely successful today, it wasn’t always: when ozone negotiations began in 1985 there was a complete lack of consensus around any regulation. We explored why the preferences of key countries changed over time in ways that made agreement increasingly attainable. We discussed how industry adaptation - such as DuPont’s investment in ozone-friendly HCFCs and HFC chemicals in the late 1980s, or Honeywell's investment in climate-friendly HFO manufacturing in the early 2020s - underpinned those changes. By examining evolution in corporate and national strategies, we answered critical questions: Why do certain countries and companies choose to combat environmental problems while others resist? How can policies reshape powerful interests? Can what we learn from ozone negotiations help us make similar progress in global climate policy? Ultimately, we emphasized how understanding the potential for positive feedback between industry and policy can help guide policymaking toward policies that maximize the chance of success in climate as well.