Ozone-Climate Interactions

The potential importance of the coupling between climate change and atmospheric ozone has been recognised for some time. However it is only recently that atmospheric scientists could even hope to start to capture the full complexity of the most important interactions in their models. In considering the role of atmospheric ozone it has been traditional largely to consider stratospheric ozone and tropospheric ozone separately, even though the importance for both regions of what happens in the upper troposphere and lower stratosphere (UTLS) has been well recognised. This approach is reflected, for example, in the respective scientific contents of the WMO-UNEP Scientific Assessments of Ozone and the assessments of the Intergovernmental Panel on Climate Change (IPCC), the essential scientific guides in the development of public policy on ozone depletion and climate change. These assessments have been based on available scientific knowledge and have been concerned, respectively, with how ozone-depleting substances affect stratospheric ozone and what chemical emissions cause tropospheric ozone to increase.