Enumerating the climate impact of disequilibrium in critical mineral supply

Abstract

Recently proposed tailpipe emissions standards aim to significant increases in electric vehicle (EV) sales in the United States. Our work examines whether this increase is achievable given potential constraints in EV mineral supply chains. We estimate a model that reflects international sourcing rules, heterogeneity in the mineral intensity of predominant battery chemistries, and long-run grid decarbonization efforts. Our efforts yield five key findings. First, compliance with the proposed standard necessitates replacing at least 10.21 million new ICEVs with EVs between 2027 and 2032. Second, based on economically viable and geologically available mineral reserves, manufacturing sufficient EVs is plausible across most battery chemistries and could, subject to the chemistry leveraged, reduce up to 457.3 million total tons of CO2e. Third, mineral production capacities of the US and its allies constrain battery production to a total of 5.09 million EV batteries between 2027 and 2032, well short of deployment requirements to meet EPA standards even if battery manufacturing is optimized to exclusively manufacture materials efficient NMC 811 batteries. Fourth, disequilibrium between mineral supply and demand results in at least 59.54 million tons of CO2e in total lost lifecycle emissions benefits. Fifth, limited present-day production of battery-grade graphite and to a lesser extent, cobalt, constrain US electric vehicle battery pack manufacturing under strict sourcing rules. We demonstrate that should mineral supply bottlenecks persist, hybrid electric vehicles may offer equivalent lifecycle emissions benefits as EVs while relaxing mineral production demands, though this represents a tradeoff of long-term momentum in electric vehicle deployment in favor of near-term carbon dioxide emissions reductions.