Nitrogen oxides (NO x) has become the priority of China's air pollution control, but the regional socioeconomic factors responsible for NO x generation are embedded with spatial disparities, which leads to different effects of air quality policy at the local level. This study applied a geographically weighted regression (GWR) model to investigate the drivers of NO x generation from energy consumption (NGEC) in China's 30 provinces, to explore nonstationary spatial effects of NGEC. The results showed that population size has always been the dominant factor in spatial NGEC across all regions of China, although there is a minor north-south difference. However, the Junfeng Wang a,b, *

Over the past 20 years, the spatial distribution of electrical generation and its relationship to cross-regional power transmission has impacted China's power generation system and significantly affected the total amount of NOx and the aggregated nitrogen intensity (ANI) of the system. An investigation of the driving mechanisms of ANI that considers the unevenness of regional electricity generation will be crucial to future improvements in the NOx efficiency of the electrical generation system in China. In this study, we built a decomposition model for ANI by incorporating the spatial distribution of electrical generation and found that the spatial distribution of electricity generation together with energy-related factors gradually caused decreases in ANI. The efficiency of electricity generation presented the dominant inhibitory effect on ANI, but its effect size has weakened since 2010. In contrast, the fossil fuel structure of thermal power shows an increasingly positive effect on changes in ANI. The primary energy composition only slightly affected changes in ANI. Moreover, the changed geographical distribution of electricity generation is non-negligible and has a positive effect on reduction of the ANI of the Chinese electrical generation system. The transferred amount of local NOx emissions by cross-provincial electricity transmission, however, could cause lead to additional environmental costs for generators. This issue should receive more attention in the future. Wang et al. (2018a) to confirm this spatial characteristic of China's power system. Please see details in Pages 10-11. 4. Comment: Conclusion. This part could point out the significance of the findings as well as summaries and bring together the main areas covered in the writing. However, the elaborations could be more plain and simple to meet the journal's standard. Response: Thank you for your suggestions. Based on your comments, we have summarized the main areas involved and clearly pointed out the significance and implications of each finding. In addition, we have modified the elaborations of the Conclusion to meet the journal's standard. See details in Pages 23-24. 5. Comment: The English of the manuscript must be improved before submission. I strongly suggest the author obtain assistance from a colleague who is well-versed in English or whose native language is English. Response: Thank you for your comments. According to your comments, we asked the help of Elsevier Webshop language service to polish the English of this manuscript. Reviewer #2: 6. Comment: The author has addressed all the reviewer comments. Response: Thank you very much for your comments. We hope that this revised manuscript meets the requirements of the journal.