Does low-carbon transition policy improve water–energy–land–food nexus performance considering ESG practice?

As the global climate crisis intensifies, the interplay between low-carbon transition policies and the sustainable management of critical resources has gained increasing scholarly and policy interest. This study investigates whether the implementation of low-carbon transition policies improves the performance of the water–energy–land–food (WELF) nexus in the context of environmental, social, and governance (ESG) practices in China. Drawing on provincial panel data from 2007 to 2023, we employ fixed effects models, heterogeneity tests, mediation effect analysis, and a PSM–DID approach to evaluate the net impact and underlying mechanisms. The results reveal that low-carbon policies significantly enhance the coupling and coordination degree of the WELF nexus, particularly in regions with stronger ESG governance and higher environmental regulation intensity. By 2023, the regional average coupling degree had increased by 2.021% compared to 2007. During the 17-year period, the mean coupling degree across all provinces and municipalities was 0.947. Mechanism analysis indicates that improvements in energy efficiency, industrial upgrading, and technological innovation are key pathways through which low-carbon policies strengthen nexus performance while aligning with ESG objectives. However, the effects vary by regional economic development level, population size, regulatory context, and market openness. These findings underscore the importance of integrating ESG principles into policy design to maximize synergies between decarbonization and holistic resource management. The study provides empirical evidence to support more targeted and adaptive low-carbon and ESG governance strategies that foster coordinated progress towards sustainability and climate goals.