The aviation industry’s quest for improved fuel efficiency has encountered significant headwinds, according to a recent study by the International Council on Clean Transportation (ICCT). The analysis, which examines fuel burn trends from 1960 to 2024, reveals that while substantial progress was made in the past, recent years have seen a worrying stagnation in efficiency gains.
From 1970 to 2024, the average block fuel intensity for newly delivered aircraft decreased by 43%. This metric, which measures fuel consumed per tonne-kilometre, reflects the industry’s commitment to reducing emissions through technological advancements. However, the ICCT study highlights that these improvements have plateaued since 2020, raising concerns about the sector’s ability to meet its net-zero carbon dioxide (CO2) emissions target by 2050.
The International Civil Aviation Organisation (ICAO) introduced fuel efficiency standards for new aircraft in 2016, aiming to drive further reductions in fuel burn. Yet, the ICCT’s findings suggest that these standards may not be stringent enough to incentivise the necessary innovations. By 2024, the average new aircraft exceeded ICAO’s 2028 fuel burn standards by 8%, indicating that current regulations are lagging behind technological capabilities.
The study also points to a decline in the number of active commercial jet aircraft manufacturers and a reduction in the variety of new aircraft types. This consolidation has limited the potential for fuel burn improvements, as fewer new, more efficient models are being introduced. The focus on refining existing designs rather than developing clean-sheet aircraft has further contributed to the slowdown in efficiency gains.
To reignite progress towards net-zero emissions, the ICCT recommends that ICAO member states consider implementing an in-production CO2 standard 15% below the existing 2028 standard. This move could incentivise the development of more fuel-efficient aircraft and align with the industry’s long-term environmental goals. Additionally, policies such as carbon pricing and differentiated landing fees could create demand for more efficient aircraft.
The analysis highlights a significant gap in fuel burn reduction between passenger and freighter aircraft. Freighters, which often rely on older designs, have lagged in efficiency improvements. The ICCT suggests that separate requirements and compliance flexibility mechanisms for freighters could help address this disparity.
