Crucial factors of the built environment for mitigating carbon emissions.

Global warming and environmental changes are becoming increasingly threatened by carbon emissions, especially in urban areas. Low-carbon cities have the co-benefits of mediating environmental threats and lowering carbon emissions. However, the direct and indirect pathways and effects between the built environment and carbon emissions remain unclear, limiting low-carbon city development. Therefore, this study used partial least squares (PLS) modeling and urban-scale data from nineteen counties in Taiwan to identify the crucial effects and pathways affecting carbon emissions. The model considered the impacts of the characteristics of urban form (i.e., density, land mix, city size, urban sprawl, and jobs-housing balance), urban function (i.e., industrial and commercial levels), urban transportation, and urban greening on carbon emissions. The results reveal that minimizing city size, urban sprawl, industrial level, and transportation status, and maximizing density, land mix, commercial levels, and urban green coverage could reduce carbon emissions. This is the first study to apply PLS modeling to identify variable pathways and evaluate both direct and indirect effects of built environment characteristics on carbon emissions. Findings demonstrated that appropriate urban policies and planning, such as compact cities, green cities, or transit-oriented development, might lower carbon emissions and thus further serve as useful strategies for building low-carbon cities.