A Comprehensive Analysis of Interflight Variability in Carbon Dioxide Emissions from Global Aviation

Aviation represents one of the most formidable sectors to address in terms of CO2 emission mitigation. The determinants of emission variability among individual flights remain inadequately understood, thereby hindering the development of effective mitigation strategies. Here, employing an extensive flight tracking data set (Flightradar24), we assess the interflight variability in CO2 emissions from global aviation with an unprecedented level of spatial and temporal granularity─down to meters and seconds, respectively. In 2019, 2020, and 2021, global aviation emitted 899 [696-1122], 469 [363-581], and 542 [418-672] Tg CO2, respectively. Based on this trajectory-level CO2 emission data set, we develop reduced-form models for over two hundred standard aircraft types that capture this flight-to-flight variability. These models offer a novel tool for understanding why emissions differ across individual flights and routes, providing crucial insights to support targeted emission reduction measures within the aviation sector. Further analysis reveals that optimizing airport flight scheduling and route planning can significantly reduce emissions. Airports with moderate flight volumes exhibit the greatest potential for relative emission reductions (51.6%, 0.12 Tg·year-1), whereas those with the highest flight volumes offer the most substantial absolute reduction potentials (12.9%, 1.39 Tg·year-1). Our study underscores the significance of CO2 emission assessment based on actual flight trajectories and addresses gaps in research on emission reductions during airport taxiing subphases.