Strategic coal-power phaseout reallocates carbon-water co-benefits towards water-stressed regions in China

Coal-power phaseout is critical for climate mitigation and increasingly relevant to water-security planning. Yet, unlike geographically uniform climate benefits, the value of water savings depends heavily on local scarcity. Whether shifting water scarcity considerations from ex-post evaluation to ex-ante pathway design can reshape the carbon-water nexus remains unclear. Here we develop a unit-level assessment framework to examine the spatiotemporal distribution of carbon and water benefits in China’s coal-power transition from 2025 to 2050 across thirteen retirement pathways, including business-as-usual (BAU) and strategies that prioritize technical, carbon, water, or integrated technical-carbon-water criteria. We find that incorporating water scarcity into coal-retirement planning enhances the scarcity value of water savings while maintaining substantial carbon-mitigation gains. Compared with BAU and technical- or carbon-prioritized pathways, the water-informed pathways increase cumulative scarcity-weighted water-saving potential (SWSP) by 18%–20% by 2050, while retaining 89%–95% of cumulative CO 2 reductions. Among them, the water-scarcity-informed pathways further redirect water-security benefits towards water-stressed regions: by 2030, 72%–97% of cumulative SWSP is allocated to high-water-risk cities, far above the 37%–60% under BAU and technical- or carbon-prioritized pathways, enabling these cities to reach half of their cumulative SWSP 1–2 years earlier. These findings indicate that incorporating water scarcity as a prioritization criterion can align climate mitigation with water-security objectives by reshaping infrastructure transition pathways.