Re-evaluating ecoinvent’s suitability for direct product material footprint calculation

Abstract Sustainable Development Goal 12.2 aims to achieve the sustainable management and efficient use of natural resources by 2030. Its target indicator, the material footprint, is a key macroeconomic indicator for impacts related to resource extraction. On the microeconomic scale, it is complemented by the product material footprint (PMF). While previous methods relied on generic characterization factors for resource extraction, this study introduces a method for the direct calculation of PMFs based on resource and other material flows included in life cycle inventories (LCI). It aims to evaluate the suitability of the LCI database ecoinvent, by comparing direct PMF calculation to a benchmark method based on characterization factors. It could be shown that ecoinvent suffices to assess the first part of the PMF – the indicator Raw Material Input (RMI), which focuses on material extraction put to an economic use. However, the results of two approaches deviate for some metals due to geographical misalignment or differences in the source data. The database further lacks information regarding unused material (both biotic and abiotic) which hampers the quantification of the second part of PMF: Total Material Requirement (TMR). Unused resource extraction still requires external data in many cases because no information is given in the database. Calculating PMF directly from LCI has advantages regarding consistency, transparency and geographical resolution, which is why we consider this a valuable approach for direct RMI quantification. However, for direct TMR quantification, ecoinvent is not suitable – yet.