Uncovering temporal-spatial drivers of vehicular NOx emissions in China

The increasing vehicle numbers in China have raised issues on effective mitigation of the vehicular NOx emissions recently. Notably, temporally growing and spatial agglomeration of high vehicular NOx emissions make an essential challenge to the mitigation strategy-makers. However, so far, there have been few studies to give insight into the socioeconomic drivers like the spatial imbalance of socioeconomic development, vehicle structure and road infrastructure to help governors. To fill the above gap, this study explores drivers of temporal change and spatial differences by building a temporal-spatial decomposition model and accounting for national and regional NOx emissions from vehicles in China from 2005 to 2015. Results show that, of all the driving forces in this study, only road vehicle carrying capacity (Delta N-VI) acts as a primary driving force for both temporal growing and spatial agglomeration of vehicular NOx emissions in China. Regional vehicle emission intensity (Delta N-NI) and road economic growth (Delta N-EI) only mainly contributed to spatial agglomeration. While economic development (Delta N-G) played a crucial role in the temporal growing of vehicular NOx emissions in China. These findings indicate that the future mitigation policy should fully cover the comprehensive socioeconomic factors, which would be useful for China and other developing countries when aiming to improve the performance of their current vehicle emissions policy system. (C) 2020 Elsevier Ltd. All rights reserved.