Frank Sherwood Rowland was an American atmospheric chemist at UC Irvine who, together with Mario Molina, made the seminal prediction that chlorofluorocarbons would deplete the stratospheric ozone layer. In a 1974 paper, Rowland and Molina calculated the fate of CFCs in the atmosphere, showing that these inert compounds would be photolyzed in the stratosphere to release chlorine radicals, which would then catalytically destroy ozone molecules at a rate far exceeding natural replenishment. This prediction, initially resisted by industry, was confirmed by the discovery of the Antarctic ozone hole in 1985 and directly led to the Montreal Protocol. Rowland shared the 1995 Nobel Prize in Chemistry with Molina and Paul Crutzen. He subsequently worked on halogen chemistry in the troposphere, the atmospheric chemistry of industrial solvents, and the global carbon cycle. Rowland was a prominent public voice for science-based environmental policy and an early advocate for action on climate change. He passed away in 2012.