Urban form and carbon emissions: indirect effects analysis using carbon spatial map data

The determination of the urban form–carbon relationships has traditionally relied on survey-based estimates, limiting analytical precision. We investigated regional heterogeneity in carbon emissions by linking urban form, socioeconomic factors, and spatial carbon footprint data. This study leveraged South Korea's newly developed Carbon Spatial Map, containing actual energy consumption data from 7.27 million buildings and comprehensive forest carbon absorption measurements, to examine the indirect pathways through which the urban form influences net carbon emissions across 227 municipalities. Using structural equation modelling, we assessed three urban-form variables: residential land share, urban population density, and residential population density. None of them directly affected net per-capita carbon emissions, but all exerted significant indirect effects through transportation, building energy, and carbon absorption pathways. Residential density emerged as the most influential factor, primarily decreasing transportation emissions and seasonal building energy consumption. Green spaces increased carbon absorption but created trade-offs by increasing transport emissions when spatially segregated. Seasonal analysis revealed consistent indirect patterns, with differential effects between summer cooling and winter heating demands. These findings fundamentally shift the focus of urban carbon management from direct impacts to strategic pathway interventions. For evidence-based planning, policies should integrate compact development with efficient transportation, high-performance buildings, and strategically distributed green infrastructure to optimize benefits while managing inherent trade-offs.