Speaker: Susan Solomon, Lee and Geraldine Martin Professor of Environmental Studies
Institution: Massachusetts Institute of Technology
The Montreal Protocol on Substances that Deplete the Ozone Layer is the most successful environmental treaty to date, having been ratified by every member state in the United Nations and mandating a complete phaseout of chlorofluorocarbon production in both developed and developing nations by 2010. However, several recent studies have provided evidence for some rogue production of CFC-11. Here I present evidence for gaps and limitations in the Montreal Protocol and in our scientific understanding, not only for CFC-11 but also for CFC-12 and CFC-113, and discuss the reasons why. I discuss recent work in my research group not only on the unexpected role of ongoing CFC emissions from “banks” in, for example, building foams, chillers, and the like, but also surprising new results on the importance of understanding the lifetimes of CFCs, including their time dependence and the role of ocean sinks.