In 1986, William Mansfield of the United Nations Environment Programme wrote:
We recognize that the potential dangers to the ozone layer from Man-made chemical releases will require emission controls. Adverse consequences can flow from the smallest depletion. A single percentage-point loss of ozone can induce a six per cent increase in certain types of disfiguring skin-cancer. Yet projections of ozone depletion related to zero growth of CFC emissions approach five per cent, and with only moderate growth double-figure depletions are projected.
We’ll never know how bad the skin cancer would have gotten, because we got the emission controls instead. Less than a year after he wrote that, the world’s governments – guided by meteorologists and aided by chemists – agreed to a gradual but complete phase-out of CFCs. Within ten years, the ozone layer was showing clear signs of recovery.
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