Atmospheric science research in the Department of Chemistry has played a leading role in demonstrating that chlorofluorocarbons (CFC) and other anthropogenic emissions led to depletion of ozone in the Arctic.
This research has been a key input into the series of assessment reports that have made the case to policymakers for strengthening the phase-out schedules for these compounds under the Montreal Protocol, an international treaty designed to protect the ozone layer, leading to significant global health and climate benefits.
For instance, John Pyle’s major contribution has been the development of chemistry–climate models for the stratosphere, which have been successfully evaluated against atmospheric observations. These include the UM_UKCA model developed in collaboration with the UK Met Office, which is now established as a gold standard in climate prediction.
Pyle’s calculations project the future evolution of ozone, explaining how atmospheric ozone concentrations are responding to regulation, with slow recovery this century. These projections show that, had the Montreal Protocol not been enacted, ozone depletion would have been even more severe, an Arctic ozone hole would have developed, and large changes in surface temperature and UV radiation would have occurred.
In collaboration with epidemiologists, Pyle has extended these studies to demonstrate the very significant benefit of the Montreal Protocol in human health by reducing future increases in skin cancer.
Pyle and colleagues have also helped to raise global awareness of these global health and climate benefits, helping to maintain support for the Protocol among policymakers, and supporting the development of legislation to limit the environmental impact of ozone-depleting substances and their replacements.
“We, in the ozone community, are so proud to have Professor John Pyle guiding the decision making of the parties to the Montreal Protocol … His work has vastly contributed to our global efforts to protect the ozone layer.”– Executive Secretary of the United Nations Ozone Secretariat 2018