Multiple strategies for road transport considering regional diversity and critical mineral supply constraints

Battery electric vehicle (BEV) is an important option for achieving zero emissions in the road transport sector; however, different regions and countries have different circumstances, and pragmatic approaches will be required for deeper and effective emissions reduction in the world. In addition, large-scale deployments of BEVs will increase the supply constraints of critical minerals. On the other hand, bioenergy also has potential for reducing CO 2 emissions, but supply constraints and conflicts among bioenergy production, food production, and biodiversity could develop. This study conducted scenario analyses on the road transport sector by using a global energy systems model that covers whole energy systems and is region- and technology-rich. The scenario analysis indicated that mixing several kinds of measures is cost-efficient for keeping the global mean temperature increase below 1.5 °C or 2.5 °C. The critical minerals of lithium, cobalt, and neodymium could be constrained in scenarios with a higher BEV share for 1.5 °C. Under the below 2.5 °C scenario and also under the below 1.5 °C scenario with direct air CO 2 capture and storage, expanding bioenergy sources could be supplied with fewer conflicts in land use for food production and biodiversity. Multiple powertrains with several energy sources, including oil, bioenergy, e-fuels, hydrogen, and electricity, can be cost-efficient for achieving below 1.5 to 2.5 °C, if several kinds of different conditions among regions and countries are considered.