Spatially and temporally differentiated characterization factors for supply risk of abiotic resources in life cycle assessment

Abstract

Life cycle assessment, a comprehensive tool to evaluate environmental impacts across a product's life cycle, traditionally focuses on "inside-out" impacts caused by the product on the environment, emphasizing resource use, global warming, and other environmental impacts. In contrast, the "outside-in" perspective considers resource availability and accessibility to industry. This second perspective was developed as a way to integrate raw material criticality assessment into LCA. The GeoPolRisk method assesses the supply risk based on global production concentration, import shares, political stability scores, and the average price of the commodity. This article introduces a characterization model for the GeoPolRisk method and calculates the Geopolitical Supply Risk Potential of using 46 raw materials across different countries in multiple years. The characterization factors show the highest values for precious metals, like platinum group metals (PGMs), reflecting their high market prices and concentrated production in geopolitically unstable regions. The results emphasize the significance of spatial and temporal variations in characterization factors, providing a nuanced assessment of supply risk of raw materials associated with the product system. Despite data limitations, the characterization factors offer a good estimate of the supply risk of raw materials available for use in product systems. A case study on photovoltaic laminate production highlights gallium, copper, and tin as significant contributors to supply risk. From an "outside-in" perspective, the case study demonstrates how the GeoPolRisk method complements traditional environmental indicators such as global warming, making it a valuable tool for assessing mineral resource supply risk in Life Cycle Assessment.