Environmental indicator systems aim to improve both the information and communication on the state of the environment and the environmental policy making. They have to fulfill scientific, functional and pragmatic requirements, e.g., consideration of ecological context, transparency and reproducibility, comprehensibility, policy relevance, international comparability, and justifiable expenditure. This paper analyzes the experiences made with the development of the German environmental indicator system and draws general conclusions toward further improvements. For Germany, an indicator system has been developed that uses the pressure-state-response approach proposed by the OECD, together with a classification in 14 environmental themes. According to the general requirements, the main criteria used for selecting the indicators are the ecological significance of the indicator, its quantifiability and data availability, and its comprehensibility and policy relevance. Altogether, about 140 indicators are selected. This high number stresses the need for further high-level aggregation, e.g., using methods developed for the valuation process in LCA. Further improvement is also needed, especially for the development of response indicators and in the area of data systematization.
