Guiding ozone layer recovery with effective science and policy on an international scale

by Stephen Montzka, NOAA/Earth System Research Laboratories/Global Monitoring Laboratory

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 (Montzka et. al, 2018, and Rigby et al., 2019). In this presentation Steve will 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.

Biography: Steve Montzka has worked as a research chemist at NOAA since the early 1990s. He leads a ongoing global-scale program making atmospheric measurements of over 30 chemicals that affect stratospheric ozone, climate, and air quality. He still gets a kick out of uncovering new insights into the workings of the global atmosphere those data provide, and using his results to inform policymakers on the international stage about the effectiveness of global environmental agreements, such as the Montreal Protocol on Substances that Deplete the Ozone Layer.