CSTPR Noontime Seminar
Guiding ozone layer recovery with effective science and policy on an international scale
by Stephen Montzka, NOAA/Earth System Research Laboratory/Global Monitoring Division
Abstract: Depletion of Earth's vital ozone layer was first noticed in the mid-1980s over Antarctica. As it became clear that human-produced chemicals were the source of the problem, all countries of the world convened and agreed to an international protocol in 1987 to address the issue. The Montreal Protocol on Substances that Deplete the Ozone Layer has been adjusted and amended numerous times in response to advances in scientific understanding. This interplay between new scientific knowledge and international policy continues today and has recently been put to the test with our discovery in 2018 of an apparent violation of the Protocol by a country or countries (https:doi.org/10.1038/s41586-018-0106-2, and https://doi.org/10.1038/s41586-019-1193-4). In this presentation I'll discuss the issue of ozone depletion, the general mechanisms of the Protocol, highlight the observational evidence we have acquired indicating an apparent violation, and describe how the Parties to the Protocol have responded to the problem, which can be viewed as a fundamental threat to the success of the Protocol and ozone layer recovery.