Cost and emissions pathways towards net-zero climate impacts in aviation

Aviation emissions are not on a trajectory consistent with Paris Climate Agreement goals. We evaluate the extent to which fuel pathways-synthetic fuels from biomass, synthetic fuels from green hydrogen and atmospheric CO2, and the direct use of green liquid hydrogen-could lead aviation towards net-zero climate impacts. Together with continued efficiency gains and contrail avoidance, but without offsets, such an energy transition could reduce lifecycle aviation CO2 emissions by 89-94% compared with year-2019 levels, despite a 2-3-fold growth in demand by 2050. The aviation sector could manage the associated cost increases, with ticket prices rising by no more than 15% compared with a no-intervention baseline leading to demand suppression of less than 14%. These pathways will require discounted investments on the order of US$0.5-2.1 trillion over a 30 yr period. However, our pathways reduce aviation CO2-equivalent emissions by only 46-69%; more action is required to mitigate non-CO2 impacts.

Automated summary

Aviation emissions do not align with the goals of the Paris Climate Agreement. By utilizing alternative fuels and increasing efficiency, it is possible to significantly reduce CO2 emissions in the aviation sector, although further action is needed to mitigate non-CO2 impacts.