Professor Wang Ke's research team's findings on the carbon dioxide reduction pathways for China's passenger aviation industry, titled "China’s aviation passenger transport can reduce CO2 emissions by 2.9 billion tons by 2050 if certain abatement options are implemented," were published in One Earth (Cell Press) in July 2023. The study indicates that if a series of technological and operational reforms begin from the current point, China's passenger aviation industry can cumulatively reduce up to 2.9 billion tons of carbon dioxide emissions by 2050.

   In 2021, the International Air Transport Association (IATA) made a commitment for the global aviation industry to achieve net-zero carbon emissions by 2050. As a resource-intensive sector, the aviation industry urgently needs to plan carbon reduction pathways to achieve this net-zero carbon emissions goal. As the world's second-largest aviation market, China's aviation industry's carbon reduction process is a crucial component of the sustainable development of the global aviation industry.

   This study focuses on China's passenger aviation sector and conducts a technical and economic analysis of carbon reduction solutions based on fleet composition, carbon emissions forecasts, and marginal abatement costs. It simulates carbon emission pathways under various combinations of carbon reduction strategies, providing a theoretical foundation for planning carbon reduction pathways in the aviation industry. Given that the variations in aviation carbon emission scenarios affect the feasibility of carbon reduction solutions and carbon emissions, this study conducts uncertainty analysis to assess the impact of uncertain factors on carbon emissions and the feasibility of carbon reduction strategies. The research findings indicate that, with the combined effects of multiple carbon reduction strategies, China is expected to achieve a cumulative carbon dioxide reduction of 2.9 billion tons by 2050. To achieve the net-zero emissions goal, according to the responsibility allocation, China's passenger aviation sector needs to reduce emissions by 2.5 billion tons from 2021 to 2050, which is less than the maximum achievable carbon reduction potential. Therefore, it is hopeful that China's passenger aviation industry will achieve its net-zero commitment after 2060.

   Among all the reduction scenarios considered in the study, the marginal abatement costs for some airline operational strategies, most of the technological emissions reduction measures, all air traffic management initiatives, and market-based measures are negative. This indicates that these emissions reduction strategies have significant cost-effectiveness, and these strategies have the potential to account for 69% of the overall emissions reduction potential. Considering the dual carbon goals and the current status of China's aviation industry, the study proposes the following carbon reduction pathway: Before reaching the carbon peak, focus primarily on reducing carbon emissions by improving existing aircraft, enhancing air traffic management, and optimizing airline operations; Afterward, shift the focus to the transformation and upgrading of aviation manufacturing technology and aviation fuels. In the cost-effective carbon reduction scenario, it is estimated that China's aviation passenger transport sector will emit approximately 95 million tons of carbon dioxide by 2050, representing a decrease of about 23% compared to the 2019 level. The average annual reduction rate is approximately 0.85%. The projected carbon dioxide emission intensity is 50.76 g/RPK, which is a 52% reduction from the 2019 level, translating to an annual reduction of nearly 2.3%.

   For China, balancing market development and emission control will be a persistent challenge. In the simulated emission reduction scenarios, China is expected to catch up with the United States in controlling aviation carbon emissions in the future. However, in terms of the cost-effectiveness of emission reduction strategies, China may slightly lag behind the United States and may face the risk of losing some cost advantages.

   The aviation fuel price has the most significant impact on the feasibility of emission reduction plans, while the uncertainty associated with technological factors has the strongest influence on carbon emissions and carbon intensity. Specifically: Aviation fuel prices significantly affect the cost-effectiveness and carbon emission pathways of emission reduction plans; The condition of fuel combustion performance is a crucial factor influencing early retirement of aircraft. When the degradation rate of fuel combustion performance increases to 0.4% per year, the marginal abatement costs of early retirement plans become negative; The market share of alternative fuels has a significant impact on the cost-effectiveness and emission reduction potential of alternative fuel plans, but its influence on the marginal abatement costs of plan combinations is weak. The use of alternative fuels to improve aviation emissions is constrained by price and production capacity; The adjustment of operational strategies should be appropriate. Excessively high load factors not only fail to achieve the desired emission reduction effects but also result in additional costs for airlines.

   The aviation industry's massive scale, indispensability, and its characteristic of operating within a cross-border and cross-policy framework make the dual carbon issues associated with it complex and multilateral. Due to its heavy reliance on fossil fuels, the aviation industry, although not the largest carbon emitter, is considered a "hard nut to crack" in terms of emissions reduction. A revolutionary replacement for fossil fuels is not something that can be achieved in the short term, and the aviation industry faces a daunting decarbonization challenge. Currently, global mechanisms for carbon reduction in aviation are not fully matured, and regional market-based policy tools or single reduction schemes alone cannot achieve the industry's emissions reduction goals. To realize sustainable, green, and low-carbon development in aviation, a multifaceted approach is required. It necessitates simultaneous efforts and the coordinated consideration of multi-level and multi-domain measures for aviation emissions reduction.