How far is it possible to ‘green’ an airplane?
Industry insiders say the sector can work harder to improve and pollute less. But environmentalists are less convinced.
Going green will be a huge challenge for the world’s biggest airlines. On the surface, the biggest issue is fuel, but many other factors contribute to a flight’s environmental impact, like the routes it takes and the food it serves on board.
So, is it possible to ever ‘green’ an airplane? Industry insiders might say yes as the sector claims to work hard to improve and pollute less. For environmentalists, the answer is less sure.
What’s clear is that the industry needs to decarbonize fast—.the World Travel and Tourism Council reported in 2023 that the travel industry is one of the most significant contributors to greenhouse gas emissions, producing 8 to 11% of the global total, mainly from transport. Of this, approximately 2.5% of global greenhouse gas emissions come from aviation.
Members of the International Air Transportation Association (IATA) agreed in 2021 to become carbon neutral by 2050 and to halve carbon emissions by 2030. This goal is technically possible, although practically difficult.
Sustainable aviation fuel—the silver bullet?
Planes currently run on highly polluting kerosene fuel, but an 80% reduction in carbon emissions is possible using sustainable aviation fuel (SAF) produced from feedstocks, cooking oils, or crops.
British Airways, for example, gets some of its SAF from waste cooking oil, which passes through a pipeline from Humberside in the North of England and feeds into London Heathrow. And Richard Branson’s Virgin Atlantic ran the first-ever flight from London to New York last November on 100% SAF.
Greener fuel doesn’t necessarily need to increase the price, either. Today, around a third of ticket prices relate to fuel costs, but increased technological efficiencies will bring this down. Every generation of airplanes and engines improves efficiency by sometimes as much as 15%, so future planes running on SAF will be more efficient.
Of course, the economic cost is not the central argument, either. Aside from helping to reduce carbon emissions, another argument for developing SAF is that it could lead to more energy independence.
The problem is that there just isn’t enough SAF available to meet demand, and that’s unlikely to change unless the industry uses crops or land that could be used for food production. This year, SAF will only provide 0.5% of global plane fuel requirements.
And even if there were enough SAF, most of today’s planes can’t run on 100% SAF. Take Airbus, whose newer aircraft currently run on a maximum blend of 50% SAF and conventional fuel, although it aims that by 2030, all new craft will be able to use 100% SAF.
But this implies a massive reinvestment by airlines into replacing all stock. There are 25,000 commercial planes currently operational globally, and plane manufacturers can’t keep up with the demand for new planes. This means that many planes in the sky will continue polluting for much longer.
It’s easy to see why airlines are unsure they can meet environmental goals. Air New Zealand recently canned its 2030 target precisely because there aren’t enough SAF or newer aircraft available.
Then there’s the cost, probably the biggest inhibitor to scaling up globally–SAF is currently up to three or four times more expensive than fossil jet fuel.
Alternatives to SAF include hydrogen, but the technology is not there yet. Electric planes for short distances and small aircraft are also options, but the size and weight of current batteries limit the technology.
If you’re looking for a greener airline, though, fly European. Starting in 2024, the EU mandates that airlines use 2% SAF. The U.S., meanwhile, is encouraging SAF take-up with incentives but is not mandating it.
AirFrance-KLM is the world’s best user of SAF at 1.1%. That’s six times more than the U.S. leader, United Airlines, which gets just 0.17% from SAF, equal to the global average.
EasyJet’s carbon emissions are around 18% lower than the global average, and it has been trialling ultra-low emission turnarounds at Bristol Airport. Likewise, Virgin Atlantic is working on developing a fleet of electric vertical take-off-and-landing (eVTOL) aircraft.
Are plant-based plane meals the answer?
Food is another way to make an impact. Thrust Carbon, an emissions intelligence platform, estimates that the carbon emissions associated with passengers’ in-flight meals account for 1% of their journey’s footprint.
It doesn’t sound like much, but it adds up. In 2023, there were 3.5 million people on flights from JFK to LHR, with total food emissions from these seats coming in equal to someone flying from NY to London 30,275 times.
This is especially true for business travelers, who make up 12% of airline passengers. If airlines switched to plant-based meals, this could lead to a 40% reduction.
Global events could hold back progress
Sometimes, sustainability is outside an airline’s control. The wars in Ukraine and Gaza and even security fears during the Paris Olympics force airlines to deviate from usual routes, possibly increasing flight times and fuel use.
Likewise, Heathrow Airport asked all airlines to carry extra kerosene into the city last summer because of supply issues. This is a controversial practice for airlines because it also increases carbon emissions.
So, sustainable aviation is complicated, and meeting goals currently depends on new technologies and sustainable aviation fuels. For the latter, though, the issues are around the availability of biomass, the cost of sustainable fuel, and the scalability of SAF production on a global scale.
So, is it possible to ever ‘green’ an airplane? The answer depends on the speed at which you need to move.
