Biodiversity loss from rare earth production for green technologies in China: a global supply chain perspective

Rare earth elements (REEs) are indispensable raw materials for green technologies, but their production process may cause significant ecological pressure. As the world's major supplier of REEs, China undertakes most of the mining and refining tasks, but it is unclear whether the Chinese rare earth supply chain has an impact on biodiversity and what part is due to foreign consumption and what part is domestic consumption. Here, we developed BLARES, a dynamic assessment framework that combines system dynamics with life cycle biodiversity impact accounting, to evaluate the impact of China's rare earth supply chain on biodiversity during the period from 2000 to 2060 under four SSP scenarios. We used mean species abundance (MSA) to measure the impact, covering land occupation and climate-driven pathways, and considering ecological time lag factors. The results show a clear ecological debt pattern. In the medium term, biodiversity pressure increases or remains high because the marginal effects brought by upstream expansion are released. Only when the used inventory of green technology products in rare earths is accumulated to stabilize the replacement of fossil energy, will the impact of the rare earth supply chain on biodiversity show a net improvement. Compared to the baseline value in 2000, the cumulative avoided biodiversity loss has exceeded 4 × 107 MSA·ha·yr by 2060. The net impact turns positive around 2040, and the cumulative net impact reaches zero around 2049, indicating a significant delay in ecological compensation. The time when the carbon balance occurs is earlier than that of biodiversity compensation, suggesting that net zero carbon emissions do not necessarily mean zero ecological emissions. From the perspective of final demand attribution, for every 1% increase in overseas demand, China's annual net biodiversity loss increases by approximately 0.031%, while for every 1% increase in the use of rare earth elements for green deployment in China, it decreases by about 0.84%. Our research results do not support the simplistic claim that “the more deployment, the better”. The transition path should be evaluated using the time of ecological compensation and the peak of medium-term pressure, rather than solely based on the final carbon emission results.