Spatiotemporal changes in inter-city sustainability impacts linked to emission challenges worldwide

Atmospheric emissions pose significant challenges to achieving the Sustainable Development Goals (SDGs). As key sources of emissions, cities are also critical actors in driving sustainable transitions. Their performance on emission-related SDG indicators is shaped not only by local factors but also by inter-city interactions. However, the spatial and temporal heterogeneity of these interactions remain poorly understood. Here, we investigate inter-city SDG interactions across 4,116 cities worldwide from 2010 to 2020, and simulate SDG performance under five interaction scenarios, including isolated and collaborative conditions. Results reveal that a 10% improvement in SDG 11.6 (particulate matter), SDG 12.4 (gaseous pollutants), and SDG 13.2 (greenhouse gases) in other cities can boost the focal city’s performance by 0.450%, 0.390%, and 0.200%, respectively. Most cities (93.51%) are influenced by other cities. Inter-city coordination can improve SDG performance by 10.81% compared to isolated efforts. These findings highlight the importance of coordinated strategies to enhance urban sustainability. Emission-related SDG performance is not just a local issue but shaped by interconnected urban systems, as impacts like greenhouse gases and air pollution cross borders. Inter-city coordination improves outcomes by 11% compared to isolated efforts.