The world’s top three manufacturers of commercial airliners were in broad agreement about what had to be done in order to achieve net-zero-carbon-emissions aviation by 2050. This was clearly shown by addresses to the Airlines Association of Southern Africa (AASA) Annual General Assembly (AGA) on Friday, by representatives of (in alphabetical order) Airbus, Boeing and Embraer. (The AGA was being held in Kleinmond, south east of Cape Town.)

Embraer was represented by GM institutional affairs Hussein Dabbas, Boeing by Africa and Middle East sales director Herb W Wallen, and Airbus by environment & sustainability marketing director Corrin Higgs. They all participated in a panel discussion on environmental considerations for aviation. The panel was moderated by environmental and wildlife specialist Dr Ian Cruikshank.

“It’s great the environment is on the [AASA] agenda,” affirmed Cruikshank. “One of the biggest challenges facing us today is sustainability.”

Wallen pointed out that aviation currently accounted for 2% of global carbon emissions. “This really impacts our world,” he affirmed. Higgs noted that, if the industry did nothing, its carbon emissions would double by 2050.

The three aerospace manufacturers were united in that the three main steps in reducing aviation carbon emissions were the adoption, by operators, of the latest-generation airliners, the scaling up of production and use of sustainable aviation fuels (SAFs), and, for the longer-term, the development of innovative technologies.

Higgs explained that the latest-generation airliners burnt less fuel, and therefore emitted less carbon, than previous-generation aircraft. Dabbas cited the example of Embraer’s new-generation E-Jet E2 family, which delivered 25% reductions in carbon dioxide emissions per passenger, in comparison with previous-generation types. Wallen agreed that airline fleet renewal was required. But, cautioned Higgs, only 20% of the world’s airliner fleets were made up of new-generation types. It would take years to replace about 80% of these fleets, composed of older, less efficient, models. However, using a variety of means, the operational efficiency of current airliner fleets could be improved by up to 10%.

SAFs were still hydrocarbons, but with much lower carbon emissions, observed Higgs. Thus, the result of fueling airliners with 100% SAFs could be carbon emission reductions of as much as 85%. Wallen agreed on the importance of 100% SAFs in cutting the industry’s carbon emissions. Dabbas concurred, but highlighted that the production of SAFs would have to be massively scaled up, and that this could require investment anywhere from $10-billion to as much as $40-billion.

Innovative technologies included hydrogen-powered aircraft, either using hydrogen fuel cells or liquid hydrogen as a fuel for gas turbine engines. Airbus was investigating such technologies and hoped, Higgs reported, to bring a zero-carbon-emissions aircraft to the market in 2035. Dabbas cautioned that hydrogen power still faced challenges. Fuel cells, for example, had a power generation efficiency of only 50%, with up to 45% of the energy produced being lost as waste heat. Further, fuel cells would be required by other major transport categories, particularly road and rail. And, for both fuel cells and liquid hydrogen fuel, there were major thermal management issues.

Dabbas continued that all-electric power was suitable only for commuter aircraft. Embraer was flying an electric flight demonstrator aircraft (a modified Ipanema crop-spraying plane) in order to get ‘hands-on’ experience with electric flight. But the group was developing an innovative technology concept aircraft family, designated Energia, which included models ranging in size from nine-passenger aircraft to 50-passenger aircraft, with different power options, including all-electric (for the smallest types) to liquid hydrogen fuel (an option for the largest types).

In the near term, Embraer was working on a new turboprop aircraft, which would have its engines mounted on pylons attached to its rear fuselage. The fuselage would be the same as that of the E-Jet E2 family. This aircraft would use new engine technology and 100% SAFs and should be on the market by 2026 or 2027.

Higgs highlighted that, to be credible, Airbus had also to reduce the carbon emissions produced by its own facilities. The group’s aim was now to cut these emissions by 63%, from 2015 levels, by 2030. To this end, the company was measuring its own carbon emissions, using consistent reporting standards.