Environmentally targeted objectives for reducing acidification in Europe

Abstract

Integrated assessment modelling has been employed as a tool for deriving cost-effective strategies based on critical loads for the reduction of acidifying pollutants in Europe. Current negotiations towards a second European Sulphur Protocol, coordinated by the United Nations Economic Commission for Europe, have identified the need for additional deposition targets as an intermediate step to achieving critical loads. Different applications of integrated modelling techniques are described, with particular emphasis on the definition of intermediate targets. These may be fixed externally to the model, or may be variable and incorporated within the optimization model. A dynamic approach to deposition targeting was shown to offer the greatest level of overall environmental protection for a given cost. However, differences between the various targeted approaches are small relative to the alternative of following an untargeted approach, a result which illustrates the flexibility of integrated assessment modelling as a useful policy tool.