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.

航空排放的轨迹与《巴黎气候协定》目标不一致。我们评估了燃料途径——来自生物质的合成燃料、来自绿色氢和大气 CO ₂的合成燃料，以及直接使用绿色液态氢——在多大程度上可以引导航空实现净零气候影响。连同持续的效率提升和轨迹避免，但没有抵消，这种能源转型可以减少生命周期航空 CO ₂尽管到 2050 年需求增长了 2-3 倍，但与 2019 年的水平相比，排放量减少了 89-94%。航空部门可以管理相关的成本增长，票价上涨不超过 15%，而没有- 干预基线导致需求抑制低于 14%。这些途径将需要在 30 年内进行大约 0.5-2.1 万亿美元的贴现投资。然而，我们的途径仅将航空 CO ₂排放量减少了 46-69%；需要采取更多行动来减轻非 CO ₂影响。