Vision 2050: Aligning aviation with the Paris Agreement

Airlines and governments have committed to achieving net-zero emissions from aviation by mid-century. In this report, we develop a roadmap to evaluate the emission impacts of ICCT scenarios for aviation technology and operations using a new Projection of Aviation Carbon Emissions (PACE) model. Our goal is to assess the extent to which measures can reduce cumulative carbon dioxide (CO₂) emissions from global aviation in line with 1.5°C, 1.75°C, and 2°C targets.

Three decarbonization scenarios—Action, Transformation, and Breakthrough—are analyzed along with a Baseline scenario, each built around six important parameters: (1) traffic; (2) aircraft technology; (3) operations; (4) zero-emission planes (ZEPs); (5) sustainable aviation fuels (SAFs); and (6) economic incentives.

Detailed findings of the study include:

• In the most ambitious (Breakthrough) scenario, early and sustained government intervention triggers widespread investments in zero-carbon aircraft and fuels, peaking fossil jet fuel use in 2025 and zeroing it out by 2050. Aviation CO₂ is cut by more than 90% below 2019 levels in 2050; cumulative emissions are consistent with 1.75ºC pathway under which aviation doesn’t increase its share of a global carbon budget.
• SAFs account for the largest share of CO₂ reduction potential, varying between 59% and 64% across scenarios. Improvements in aircraft technical and operational efficiency contribute an additional one-third of CO₂ mitigation. Zero-emission planes powered by hydrogen account for up to 5% of emission reductions in 2050.
• Under all scenarios, fuel and ticket costs rise along with the introduction of SAFs. Under the Breakthrough scenario, fuel costs increase by 34% and 70% in 2030 and 2050, respectively, due to the adoption of these more expensive fuels. Thus, policies like a SAF mandate, low carbon fuel standard, carbon taxes, and/or a frequent flier levy will be needed to bridge the price gap between alternative and fossil jet fuels.

Overall, we conclude that new technologies under development can cut aviation CO₂ to near zero in 2050, but that immediate action is needed from governments to peak emissions this decade to put aviation on a 1.75ºC pathway. Either atmospheric carbon removals or curbs to traffic growth will be needed to meet a 1.5ºC temperature pathway.

Figure. Cumulative global aviation CO₂ emissions under various modeling scenarios, 2020-2050

This paper was revised on 30 June, 2023 to correct captions on Figures 10 (ES-2) and B-1 and to amend an estimate of projected ticket price increases. After taking into account fuel efficiency gains through 2050, ticket prices are expected to rise by about 6% under the Breakthrough case. The original can be found here.