Towards a Simplified Model to Describe Ozone Formation in Europe

Air pollution is a multi-faceted problem with a variety of pollutants released from a large number of different anthropogenic activities causing a multitude of environmental effects. Cost-effective strategies to reduce negative impacts of air pollution must take account of these complexities and consider the individual aspects of the air pollution problem simultaneously. Integrated assessment models provide a consistent framework for a systematic analysis of alternative strategies. One of such models, the RAINS (Regional Acidification Information and Simulation) model developed at IIASA, has been used as a scientific support tool for the international discussions on further reductions of emissions of sulfur dioxide in Europe, which led in 1994 to an agreement on the 'Second Sulfur Protocol'. The perceived success of this agreement motivated further work on extending model analysis to additional pollutants and effects. Elevated levels of tropospheric ozone are currently considered as one of the major air quality problems in Europe, calling for balanced reductions of emissions of nitrogen oxides and volatile organic compounds. A major obstacle for developing a practical integrated assessment model for ozone is the complexity and the size of most of the current models on atmospheric ozone formation. This paper tries to identify elements for potential model simplifications, which could contribute to the development of an operational European-scale ozone formation model. Such a simplified model would establish the core of an integrated assessment model for ozone formation, linking information on emissions and emission control costs with an assessment of their environmental impacts