Researchers from Tsinghua University and Harvard University published a study projecting that China's aviation NOx emissions will rise 65% to 124% and particulate matter emissions will rise 59% to 149% between 2019 and 2035, depending on the pace of technology adoption and sustainable aviation fuel use. The study links city-level air travel demand, fleet turnover, and route-level flight operations to project how aviation activity and its emissions will redistribute across Chinese cities as the country's civil aviation sector continues to expand.
The projected growth is not concentrated where it has been historically. Megacities' share of total aviation NOx emissions is projected to fall from more than 40% to about 30% by 2035, even as their absolute emissions keep rising, because medium-sized cities are growing faster, with route-level emissions in those cities projected to more than double. Newly built airports, many located in western China, are projected to contribute an additional 17% of national aviation NOx emissions by 2035. In several megacities, the study projects that low-altitude aviation NOx emissions will surpass those from road transport, making aviation a dominant local transportation-related pollution source rather than a secondary one.
Atmospheric modeling in the study estimates aviation-attributed PM2.5 and ozone could account for up to 9% and 14% of ambient concentrations, respectively, in developed urban regions by 2030. The researchers note that technological improvements, including sustainable aviation fuel adoption that remains far below the levels needed for meaningful emissions reductions, are not on pace to offset demand growth. Global SAF scaling continues to depend on policy clarity and feedstock diversification more than on aircraft technology alone, a dynamic the study's scenarios reflect directly, and cost gaps between SAF and conventional jet fuel remain a persistent barrier in other major aviation markets as well.
