Study: Aircraft Delivery Projections Inconsistent With Net-Zero 2050

All commercial aircraft delivered after 2035 will need to have net-zero carbon emissions throughout their lifetime if the aviation industry is to meet its target of being net-zero by 2050, says a new report by the nonprofit International Council for Clean Transportation (ICCT).

That will entail using 100% sustainable aviation fuel with very low lifecycle CO₂ emissions, electric or hydrogen propulsion, reducing aircraft deliveries, or actively removing carbon from the atmosphere to offset aviation’s emissions.

The report by the ICCT, a Washington-based independent research organization, concludes that current manufacturer delivery projections are not consistent with the net-zero target set by the aviation industry in 2022.

Using an average from four industry decarbonization road maps, the think tank calculated that the industry has a budget of 18.4 billion metric tons of cumulative CO₂ emissions by 2050 to work within if it is to be net-zero by the middle of the decade.

The fleet of aircraft already in service in 2023 is expected to emit 9 billion tons of CO₂ over the remainder of their useful lives, ICCT calculates, consuming almost 50% of the net-zero budget. New deliveries of aircraft would then fully deplete the net-zero carbon budget by 2032 or 2037 in baseline and optimistic scenarios studied by the organization.

“After that time, any emissions from new conventional aircraft that are not removed by CDR [carbon dioxide removal] would exceed the available carbon budget and, therefore, be incompatible with a net-zero goal,” ICCT says. The amount of direct air capture of CO₂ required to stay within the net-zero budget ranges from 22 billion tons in the baseline scenario to 5 billion tons in the optimistic scenario, the organization calculates.

“In other words, manufacturers must go net-zero about 15 years before airlines. After that time, all newly delivered aircraft must be fueled by 100% SAFs, hydrogen or electricity, all with very low lifecycle emissions, or have their emissions fully removed using widescale CDR, for airlines to meet their climate goals,” ICCT says.

In the conservative baseline scenario, aircraft continue to burn fossil jet fuel and emissions increase linearly, doubling by 2035 due to fleet growth. The alternative optimistic scenario assumes substantial uptake of sustainable aviation fuel (SAF) and aggressive fuel-efficiency improvements reduce the lifetime CO₂ emissions of new-delivery aircraft by more than 50%.

“We model that an aircraft is delivered in 2030, say, and it’s used for 25 years. We assume it’s using a certain blend of SAF in every year of its operation. In 2035, it’s using 20% SAF. By 2050, it would be using 70%. That’s based on the ReFuelEU mandate,” says Dan Rutherford, ICCT’s senior director of research. “What this is showing is that SAF blends and fuel efficiency alone are insufficient. We need to go above and beyond. Any new aircraft delivered in 2035 or after would need to be net-zero through its entire lifetime. That’s above and beyond fuel efficiency and SAF blends.”

“Given that hydrogen and electric are going to be a very small part of the equation, even by 2050, it has to be carbon dioxide removal,” says Rutherford, noting that only United Airlines CEO Scott Kirby has talked publicly about the need for CO₂ removal. “Or the alternative is manufacturers sell fewer planes,” Rutherford says.

Under a net-zero budget, ICCT estimates manufacturers could only deliver about 24,000 conventional aircraft by 2042, or about 62% of projected deliveries, under the baseline scenario. The remaining 14,500 aircraft would need to be net-zero throughout their lifetimes.

Under the optimistic scenario, an additional 4,500 conventional aircraft could be delivered. “Even then, manufacturers will need to deliver at least 10,000 net-zero aircraft powered by hydrogen, electricity or 100% SAF by 2042,” ICCT calculates.

“The other way to interpret that figure is if manufacturers don’t develop a zero-emission airplane, that’s the number of airplanes that they have to not deliver,” Rutherford says. “Basically, the delivery projections that manufacturers are putting out are not consistent with developing new types and a net-zero carbon budget.”

The ICCT report recommends that manufacturers ensure all new aircraft can burn 100% SAF, not just blends, starting in 2030; accelerate efforts to develop zero-emission aircraft by 2035, especially those powered by hydrogen; and establish stringent targets requiring that aircraft they deliver emit fewer greenhouse gases throughout their lifetimes. 

To view the ICCT report, click here