Consumption-based material flow indicators - Comparing six ways of calculating the Austrian raw material consumption providing six results

Understanding the environmental implications of consumption and production depends on appropriate monitoring tools. Material flow accounting (MFA) is a method to monitor natural resource use by countries and has been widely used in research and policy. However, the increasing globalization requires the consideration of 'embodied' material use of traded products. The indicator raw material consumption (RMC) represents the material use - no matter where in the world it occurs - associated with domestic final demand. It provides a consumption-based perspective complementary to the MFA indicators that have a territorial focus. Several studies on RMC have been presented recently but with diverging results; hence, a better understanding of the underlying differences is needed. This article presents a comparison of Austrian RMC for the year 2007 calculated by six different approaches (3 multi-regional input-output (MRIO) and 3 hybrid life-cycle analysis-IO approaches). Five approaches result in an RMC higher than the domestic material consumption (DMC). One hybrid LCA-IO approach calculates RMC to be lower than DMC. For specific material categories, results diverge by 50% or more. Due to the policy relevance of the RMC and DMC indicators it is paramount that their robustness is enhanced, which needs both data and method harmonization.