Emissions

The full-flight carbon dioxide (CO₂) emissions of all flights departing from EU27+EFTA airports have followed a similar pattern to noise and were estimated to be 133 million tonnes in 2023, which is 10% below the 2019 peak (

). Mainline and low-cost operators accounted for 52% and 28% of CO₂ emissions respectively in 2023 ( ). Single-aisle and twin-aisle jets emitted 96% of total CO₂ emissions (almost equally split between the two categories), while long-distance flights (above 4 000 km) represented 46% ( ). Flights with a destination outside EU27- EFTA accounted for 61% of CO₂ emissions ( ).

In the short term, market-based measures are expected to stabilise European aviation’s net (i.e. lifecycle) CO₂ emissions, while sustainable aviation fuels still show the greatest potential for reduction in the 2050 timeframe (

). During 2023 the EU Emissions Trading System (ETS) achieved net CO₂ reductions of about 25 million tonnes (Mt) through the purchase of allowances by operators. In combination, the EU ETS, the CH ETS and the ICAO Carbon Offsetting and Reduction Scheme for International Aviation (CORSIA) could yield an average 39 Mt net CO₂ reduction per year over the period 2024-2026 (see Market Based Measures chapter for details).

Meeting the ReFuelEU Aviation 

 supply mandate for Sustainable Aviation Fuels (SAF) would cut net CO₂ emissions by at least 65 Mt (47%) in 2050 under the base traffic scenario. This is lower than the estimated 60.8% emissions reduction in the European Commission Impact Assessment for ReFuelEU Aviation due to more conservative assumptions  . The emission reductions in Figure 1.10b are based on the final ReFuelEU Aviation minimum level of SAF supply and emissions reductions in line with the mandate and sustainability criteria (see Appendix C for more details on the SAF scenario). Under ReFuelEU Aviation, EASA will collect data from aircraft operators and aviation fuel suppliers on SAF, including their sustainability characteristics. The actual reported values of SAF uptake and the CO₂eq emissions reductions for each SAF category will be used to inform the net CO₂ estimates in future versions of this report.

Electric and hydrogen aircraft were assumed to deliver an additional 5% net CO₂ reduction by 2050 and may have a larger emission reduction potential beyond this date.

Compared to the previous report, a slightly more conservative future engine technology scenario was used to predict emissions of nitrogen oxides (NO_X) out to 2050. The updated emissions trends chart (

) confirms that mitigating the growth in NO_X emissions over the next decades remains a challenge. The same conclusion applies to a lesser extent to volatile particulate matter (PM) emissions (Figure 1.15). Emissions of carbon monoxide (CO), unburnt hydrocarbons (HC) and non-volatile PM are expected to stabilise or even reduce by 2050 through the effect of fleet renewal and ATM improvements.

See Chapter 2 on Environmental Impacts for further information on the impacts of air pollutants, including ultrafine particles from aircraft, which is an emerging pollutant of concern that will be monitored under the revised EU Ambient Air Quality Directive.