The material-energy nexus in net-zero transition scenarios: exploring environmental trade-offs and uncertainties

As countries pursue net-zero energy systems, material demands intensify. This study develops a framework combining energy system modeling and life cycle assessment to quantify environmental impacts and material needs of energy transition scenarios. We apply it to Switzerland's net-zero scenario, using global sensitivity analysis to assess uncertainties in material intensity, efficiency, and market shares of energy technologies. Results reveal that Switzerland's domestic net-zero goal is met, with life-cycle greenhouse gas emissions decreasing from 40 to 4 megatonnes CO 2 -eq between 2020 and 2050. While uncertainties have limited influence on environmental indicators, demand for critical raw materials rises and varies substantially. For instance, lithium demand increases tenfold by 2050, with estimates ranging from 800 to 3,000 tonnes annually. Technological improvements and sub-technology choices, such as lithium-reduced battery chemistries, help mitigate CRM pressures even as storage capacity grows. Findings highlight the need to integrate material considerations into energy planning for sustainable, resilient transitions.