Approaches to analyse interactions of climate change, acidification and ozone

The following research questions have been addressed:

1. Which interactions exist between acidification, tropospheric ozone formation, climate change and stratospheric ozone depletion?
2. How can these interactions be analysed either by means of existing models, or by combining parts of these models, or by new model structures focusing on these interactions?
3. Which data is required at the appropriate spatial and temporal scales for these themes, and how can these different scales be integrated?
4. Which information is already available in existing emissions inventories and existing models?

For a combined analysis of climate changes and transboundary air pollution, it is proposed to first decouple climate change calculations from air pollution calculations in an analysis at the global level, in order to determine emission reduction targets for greenhouse gases for Europe. For this purpose, calculations could first be performed with MERGE or ECHAM for climate change in order to establish emission targets for Europe.

Next, the optimized emission levels (and of course also the calculated concentration fields and changed meteorological conditions) should be used as one of the restrictions in an optimisation analysis at the European level, using a newly developed model, based on elements of the RAINS model and the more detailed LOTOS system for transboundary air pollution. Subsequently with this model optimisation runs should be performed to calculate optimal emission reduction strategies for transboundary air pollution and emissions of greenhouse gases, considering the interactions as identified in this study.