A Bottom-Up Emissions Inventory Reveals the Long-Term Changes of Aviation Co2 Emissions in Chinese Cities

In the context of China’s carbon peak and carbon neutrality commitments, aviation CO2 emissions play an increasingly important role in achieving China’s carbon peak and carbon neutrality targets. Based on China’s full caliber flight data for four consecutive years (over 30 million flights), this study constructed an aviation CO2 emissions assessment system from the bottom up according to flight sortie information and aircraft engine parameters. The changing trend of aviation CO2 emissions in Chinese provinces and cities between 2017 and 2020 was evaluated used this method. The results showed that China’s aviation CO2 emissions were 104.8, 159.2, 185.1, and 112.1 million tons (Mt) in 2017, 2018, 2019, and 2020, respectively, with annual growth rates of 51.9%, 16.3%, and −39.4% in 2018, 2019, and 2020, respectively. Aviation CO2 emissions in all Chinese provinces showed a growth trend before the COVID-19 pandemic and decreased to different degrees after the outbreak of the pandemic. Over 84% of aviation emissions were contributed by 10% of densely populated and economically developed cities in China. China is still in a period of growing demand for air transportation, and with the effective control of COVID-19, aviation CO2 emissions have rebounded significantly and continue to grow.