Ozone layer science and its assessments

Stratospheric ozone layer depletion due to manmade halogenated chemicals is well established. The Montreal Protocol was enacted over 20 years back to curb the depletion of the ozone layer and set the path for the “recovery” of the ozone layer. This science is assessed to enable policy makers in their decision- making and scientists in their research. The close working between the assessment and science/research have helped advance both the ozone layer science and policy-making. It is now acknowledged the ozone layer is on its way to recovery and the Montreal Protocol is a success.

Given this success, it is time to ask what has worked well and what other considerations are worthy of pursuit. I will describe the findings of the latest international assessment of the ozone layer science completed in 2010 and discuss likely issues for the future for ozone layer science and the policies of the Montreal Protocol.