Environmental synergies and trade-offs in the rapid transition of China's electricity system

China's power sector is undergoing rapid decarbonisation while simultaneously expanding generation. Although the power sector's greenhouse gas (GHG) emission trajectories under various decarbonisation pathways have been extensively researched, other non-GHG environmental implications remain poorly investigated, particularly due to limited spatially resolved data to trace where the actual impact occurs globally. Therefore, this study employs a spatially explicit life cycle assessment method to evaluate the environmental synergies and trade-offs of China's power sector under two future scenarios in 2050. A comprehensive portfolio of provincial-level, technology-specific life cycle inventories for China's current and future power systems are compiled, incorporating country-specific supply chain processes for key materials. The results show substantial decreases in GHG Emissions, from 5.5 Gt CO 2 eq in 2020 to 3.2 and − 1.02 Gt CO 2 eq by 2050 under the two scenarios. Synergies are observed between GHG Emissions and Particulate Matter Formation, with the latter declining by 31–70% compared to 2020. However, these synergies are accompanied by significant environmental trade-offs, as Land Transformation, Freshwater Eutrophication and Mineral Resource Use increase significantly. Spatially, land and water related impacts are gradually concentrating in China, while mineral related impacts are increasingly spreading to other countries and regions. Provincial contributions to national total impacts are also significantly reshaped under future scenarios because different power system configurations redistribute the ultimate cause of environmental impacts. This study highlights the need for climate policies to balance climate targets with broader environmental considerations for sustainable decarbonisation and to coordinate tailored mitigation across technologies, provinces, and global supply chains to support a more equitable and just transition.