An Uncertain Sky: Debating science in the CFC-ozone issue

In 1974, two chemists made the alarming discovery that the ubiquitous chemicals, chlorofluorocarbons (CFCs), had been depleting stratospheric ozone. What followed was a non-linear and oftentimes tense struggle to validate the CFC-ozone depletion theory against its critics. This thesis expands on other scholarship by both describing the history of the CFC-ozone issue, and analysing the treatment of scientific doubt and uncertainty over time. It gives a history of the key developments in the controversy, focusing on the period from 1974 to 1984. It shows what the CFC-ozone issue reveals about sources of scientific uncertainty – including methods that are inherently uncertain, and uncertainty and doubt that were culturally manufactured by human processes and structures. This thesis challenges the common teleological narrative of the CFC-ozone issue as a clear-cut triumph of wisdom and action over scepticism, particularly when compared to other environmental issues, such as climate change. Drawing on theories regarding uncertain knowledge and manufacturing doubt, this thesis finds that despite significant areas of relative certainty and consensus, the story of CFCs and ozone depletion contains many of the same elements as other fraught environmental issues. Sceptics of CFC-ozone depletion magnified existing areas of uncertainty, manufactured new areas of uncertainty, conflated theoretical knowledge with uncertain knowledge, and utilised economic arguments, all in an effort to undermine scientific findings.