IEA (2020), Tracking Transport 2020, IEA, Paris https://www.iea.org/reports/tracking-transport-2020
Tracking progress 2020
Aviation emissions rose rapidly, at an average annual rate of 2.0% during 2000-19, with 5% average yearly rises in total commercial passenger flight activity since 2000. As most (>99.5%) aviation relies on jet kerosene, and as most jet kerosene (>85%) is used by commercial passenger aviation, the gap between these two metrics is largely explained by operational and technical efficiency measures adopted by commercial airlines, including new aircraft purchases. The energy intensity of commercial passenger aviation has decreased 2.8% per year on average, but improvements have slackened over time, and they must be maintained to limit fuel combustion to volumes at which SAFs – low-carbon alternatives to fossil-based jet kerosene – can power commercial aircraft. Near to mid-term priorities include implementing fiscal and regulatory measures that promote exploitation of operational and technical efficiency and managing the investment risks. These risks exist for developing and deploying clean sheet airframes, new engines and propulsion systems, and for production low-lifecycle GHG-emissions SAF.