Significance of country-specific context in metal scarcity assessment from a perspective of short-term mining capacity

The sustainability of metal use is threatened by increasing global demand. The concept of scarcity in mining capacity is of particular relevance to the sustainability of metals; it represents an imbalance between availability and mine production and is determined by socio-economic conditions. Although socio-economic conditions vary by region or country, few studies have assessed the scarcity in mining capacity of metals on such regional scales, which fails to assess potential risks for local sustainability. Here, we propose a country-specific indicator for the assessment of scarcity in mining capacity of metals that reflects differences in national conditions. We apply our methodology to 16 representative metals for 2000, 2010 and 2017. The results demonstrate our indicator of country-specific scarcity varies by 1-3 orders of magnitude for the metals considered, depending on reserves and mine production in producing countries. Furthermore, an indicator that represents the degree of concentrated production in high-scarcity countries is introduced, which reveals the dependency on high-scarcity countries for Al, REE, Li, and Sn. For the assessment of the effects of specific demand on the potential risks of threatening local sustainability, we define the severity of mine production that represents the magnitude of the potential risks determined by both country-specific mine production and scarcity. Analysis of metal scarcity considering country-specific conditions can reveal the potential risks for local sustainability associated with metal production and support metal users to seek effective solutions to reduce the potential risks, which is not considered in existing criticality assessments.