Exploring the Impact of Recycling on Demand-Supply Balance of Critical Materials in Green Transition: A Dynamic Multi-Regional Waste Input-Output Analysis.

Addressing our climate urgency requires various renewable and low-carbon technologies, which often contain critical materials that face potential supply risks. Existing studies on the critical material implications of green transition have used various methodologies, each with pros and cons in providing a system understanding. Here, we integrated the dynamic material flow analysis and input-output modeling principles in an integrated multi-regional waste input-output model to assess the demand-supply balance and recycling potentials for cobalt, lithium, neodymium, and dysprosium under various energy scenarios projected to 2050. We show that although all four critical materials are likely to face strong growth in annual demand (as high as a factor of 25 compared to the 2015 level), only cobalt has a higher cumulative demand by 2050 than the known reserves. Nevertheless, considering the sheer scale of demand increase and long lead time of opening or expanding new mines, recycling efforts are urgently needed to supplement primary supply toward global green transition. This model integration is proven useful and can be extended to more critical materials and green technologies.