Spatial differentiation of daily travel carbon emissions in small- and medium-sized cities: An empirical study in Kaifeng, China

Abstract Issues relating to low-carbon transportation have received increasing attention in recent years for two competing reasons: the effort to slow down global warming and the upward trend in private vehicle ownership in China. Residential carbon emissions and the mechanisms influencing them have been adequately addressed by the published literature. However, both the built environment and socio-economic factors are spatially heterogeneous within cities, and this can be expected to lead to a corresponding spatial heterogeneity in residential carbon emissions. To better characterize spatial heterogeneity in the mechanisms influencing carbon emissions, this study collected fine-scale spatially-distributed data pertaining to carbon emissions arising from the travel activities of residents in Kaifeng City. The spatial characteristics of and factors influencing household travel carbon emissions were then investigated using spatial auto-correlation analysis and the geographical weighted regression (GWR) method. The results show that areas with high values of household travel carbon emissions were primarily in the new urban development zone and in the more rapidly-expanding built-up areas in the outer layer of the city. Additionally, a large average distance between working and living locations in the newly-built commercial housing communities in the rapidly urbanizing areas is a leading factor increasing resident travel carbon emissions. Meanwhile, the long average distances traveled for schooling on account of the currently imbalanced development of education resources is another leading factor for increasing residential travel carbon emissions. The conclusions of this research elucidate the spatial heterogeneity in the mechanisms influencing residential travel carbon emissions within the city. In particular, this study confirms that urban sprawl is a leading factor in driving residential travel behavior and thus carbon emissions. More importantly, this study demonstrates that the documented inequality in resident travel-related carbon emissions does not result from economic (e.g., household income) inequality. Instead, it is caused by the existence of inequality in the allocation of socioeconomic infrastructure (e.g., schools). It is our expectation that the results of this study can be used as a valuable reference for planning low-carbon cities.