A Planetary Boundary\nfor Mineral, Metal, and Fossil\nResource Extraction Rates: How Much Primary Materials Can a Circular\nEconomy Extract?

Resource consumption is expected to further increase\nin the next\ndecades. A circular economy could decrease the environmental impact\nof this resource consumption by minimizing the primary raw materials\nconsumption and minimizing emissions that render materials inaccessible\nfor further use. However, such a circular economy will still have\nprimary raw material inflows, due to population growth, stock expansion,\nenergy transition, and inevitable dissipation. The potential magnitude\nof such primary raw material inflows in a circular economy remains\nunclear. To address this uncertainty, the planetary boundary framework,\nwhich defines absolute limits on resource and emission flows, could\nbe utilized. Although this framework incorporates aspects of biomass,\nwater, and land use, mineral, metal, and fossil resources are not\nincluded. This study provides a principle for a planetary boundary\nfor these three resources, based on the net accessibility rate and\nan allocated share of the accessible resource stock in the ecosphere.\nInter- and intragenerational equality are crucial for determining\nthis allocated share and for quantifying a sustainable rate of resource\nextraction in (an economy transitioning toward) a circular economy.\nNext steps to operationalize this principle provide further guidance\nto determine the safe operating space for mineral, metal, and fossil\nresource extraction.