Resource consumption is expected to further increase in the next decades. A circular economy could decrease the environmental impact of this resource consumption by minimizing the primary raw materials consumption and minimizing emissions that render materials inaccessible for further use. However, such a circular economy will still have primary raw material inflows, due to population growth, stock expansion, energy transition, and inevitable dissipation. The potential magnitude of such primary raw material inflows in a circular economy remains unclear. To address this uncertainty, the planetary boundary framework, which defines absolute limits on resource and emission flows, could be utilized. Although this framework incorporates aspects of biomass, water, and land use, mineral, metal, and fossil resources are not included. This study provides a principle for a planetary boundary for these three resources, based on the net accessibility rate and an allocated share of the accessible resource stock in the ecosphere. Inter- and intragenerational equality are crucial for determining this allocated share and for quantifying a sustainable rate of resource extraction in (an economy transitioning toward) a circular economy. Next steps to operationalize this principle provide further guidance to determine the safe operating space for mineral, metal, and fossil resource extraction.

中文翻译：

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矿物、金属和化石资源开采率的地球边界：循环经济可以提取多少初级材料？


预计未来几十年资源消耗将进一步增加。循环经济可以通过最大限度地减少初级原材料消耗和最大限度地减少导致材料无法进一步使用的排放来减少这种资源消耗对环境的影响。然而，由于人口增长、存量扩张、能源转型和不可避免的耗散，这种循环经济仍将有主要原材料流入。在循环经济中，这种初级原材料流入的潜在规模尚不清楚。为了解决这种不确定性，可以利用行星边界框架，该框架定义了资源和排放流量的绝对限制。尽管该框架包含生物质、水和土地利用的各个方面，但不包括矿物、金属和化石资源。本研究为这三种资源的地球边界提供了一个原则，该原则基于净可达率和生态圈中可利用资源存量的分配份额。代际和代内平等对于确定这一分配的份额和量化（向循环经济过渡的经济体）中可持续的资源开采率至关重要。实施这一原则的后续步骤为确定矿物、金属和化石资源开采的安全操作空间提供了进一步的指导。