Peak patterns and drivers of city-level daily CO2 emissions in China

Abstract

Cities are the primary carbon emitters in China and play a critical role in achieving national and regional emission-reduction targets. However, because existing CO2 emission datasets are mostly limited to national and provincial levels and have significant time lags, there are few studies on urban emission patterns and drivers below the annual level. In this study, utilizing near-real-time daily CO2 emission data from Carbon Monitor Cities-China, we analyzed the seasonality and peak patterns of city-level emissions and conducted a decomposition of emission drivers by sector based on sociometric and natural factors. Our results indicated that most cities in China exhibited seasonal emissions, with peak emissions occurring during winter. However, heavily industrialized cities tend to produce high year-round emissions. The residential and power sectors are crucial for reducing emissions in winter-peaked cities, whereas the industrial and power sectors are the primary energy consumers in non-winter-peaked cities. The results of the decomposition analysis show that the emission structure of the service industry and the impact of temperature on power generation are the primary drivers of CO2 emissions during winter. The above analysis offers recommendations for developing emission-reduction policies for various types of cities. Service-based cities should concentrate their efforts on reducing emissions from tertiary industries, whereas energy-dependent cities should continue to focus on controlling emissions from secondary industries such as industry and power. In addition, both service-based and energy-dependent cities must address the significant impact of heating demands on emissions.