Polycentric urban development and carbon emission Intensity——An examination of 268 Chinese cities

With the global proliferation of polycentric urban structures exhibiting diverse characteristics and development patterns, understanding their differential impacts on carbon emissions becomes imperative for formulating place-based sustainable urban strategies. By analyzing 47 million enterprise distribution data points, this study maps the polycentric structures of 268 Chinese cities (2006–2019). Our analysis demonstrates that this enterprise-based dataset better captures urban centers' intrinsic characteristics compared to conventional datasets, yielding superior measurement accuracy. Using this validated method, we quantify polycentric structures' impact on carbon emission intensity. Results reveal significant emission mitigation effects: each unit increase in polycentricity correlates with 3.501 % emission reduction, with northern and non-resource-based cities exhibiting particular sensitivity. Promoting the economic effects of agglomeration and alleviating congestion diseconomies are ways for polycentric spatial structures to reduce carbon emissions. We further develop a tripartite metric system (Number, Balance, Compactness) characterizing structural evolution along three dimensions: fragmentation-integration, centralization-decentralization, compactness-dispersal. Building on this framework, we systematically categorize urban polycentric structures into eight distinct development patterns, each demonstrating unique socioeconomic signatures. Further analysis reveals that not all development patterns demonstrate sustainability. Only Patterns 1 and 5 exhibit significant carbon emission reduction effects. The common characteristic shared by these effective patterns lies in fragmentation and dispersal features. This innovation not only addresses whether polycentric spatial structures contribute to carbon emission reduction, but furthermore identifies which specific development patterns demonstrate enhanced effectiveness in low-carbon transitions. Finally, this article explores the potential causes of these phenomena and proposes corresponding policy recommendations.