The challenge to measure regional sink constraints: A new indicator for policy performance evaluation regarding sinks

Today`s “anthropogenic metabolism” involves a huge material turnover. After utilization, materials either remain in the anthroposphere as recycling products, or they leave the anthroposphere as waste and emission flows. To accommodate these materials without jeopardizing human and environmental health, limited natural sinks are available; thus, man-made sinks have to be provided where natural sinks are missing or overloaded. The goal of this study is the development of a new indicator that specifies on a regional scale which fractions of anthropogenic material flows to sinks are acceptable. Case studies show that appropriate governance of anthropogenic material flows and stocks is needed in order to avoid overloading of sinks, resulting in harm on humans and the environmental. Based on the results, the advantage of using this indicator is threefold: First, it satisfies the need for transparency and accountability in policy performance evaluations. Second, it allows comparing and benchmarking regions in view of sink limitations. Third, the indicator aggregates complex information into an easy to understand score and is therefore highly instrumental for communicating scientific results to decision makers and the public.