The Cirium Flight Emissions Review is a data-driven snapshot of how the aviation industry is performing on carbon efficiency and crucially, who is improving.
The report brings together global and regional rankings to show which airlines are operating most efficiently in terms of emissions per unit of capacity (CO₂ per ASK), highlighting both the world’s biggest carriers and performance within key markets like North America, Western Europe, Southeast Asia and Latin America, as well as major long-haul corridors such as transatlantic and transpacific routes. It goes beyond airline-level comparisons to examine specific routes, pinpointing where emissions efficiency has improved the most year-on-year and identifying the operational changes such as aircraft upgrades, that made the difference.
Throughout, the report pairs current performance with year-on-year change, giving a clear picture not just of who is leading today, but who is actively progressing. The result is a practical, evidence-based view of how data, fleet decisions and operational strategy are shaping aviation’s path toward lower emissions.
