The aviation industry can hit its emissions goals, but it needs new fuels
It will be difficult, but not impossible, to reduce carbon emissions from planes. With enough funding, policy support, and alternative fuel, aviation can make enough progress to help the world reach global climate targets by 2050, according to a new report.
Today, about 3% of global greenhouse-gas emissions come from aviation. Some airlines and industry groups have made pledges to reach net-zero emissions by 2050, but these plans often don’t include details on how to get there.
The new report, published by the International Council on Clean Transportation (ICCT), a nonprofit research group, outlines possible paths for aviation to reduce emissions enough to do its part in keeping global warming at less than 2 degC above preindustrial levels, the target set by the Paris agreement. To reach that goal, aviation must take immediate action and provide significant policy support for technologies such as alternative fuels.
Aviation is a sector that’s notoriously difficult for decarbonization. Technology options are limited by strict safety and operating requirements. Equipment has a long lifetime, so a plane built today will still be flying in 2050. Technical progress must be made quickly to reduce emissions in the future.
“If we want to decarbonize our aviation sector, we have to do it now,” says Lynnette ,, a principal research fellow at University College London.
Keeping emissions low enough to stay under 2 degC of warming would mean cutting aviation’s annual emissions in 2050 to about half of currently projected levels–a daunting task for an industry that’s expected to grow swiftly in the next few decades. For the industry to hit that target, its emissions would need to peak and start falling by 2030, says Brandon Graver, one of the report authors and a senior aviation researcher at the ICCT. To limit global warming further, emissions must start falling by 1. 75 degC, emissions will need to start falling as soon as 2025.
In the ICCT analysis, about 60% of emissions reductions are projected to come from low-carbon fuels.
But new fuels still have a long way before they can make that kind of impact. About 0.5% of the total fuel supply in is available as alternative jet fuel. 05% of the total fuel supply in 2020. Judging from 2018 numbers, a full year’s supply of non-fossil fuel would power global aviation for about 10 minutes.
To keep up with demand in 2050, even in the most conservative estimate, alternative fuel supply would need to grow by about 3,000 times from 2020 levels.
The small amount of commercially available alternative fuels today is largely made from oils, greases, and waste fats. However, the supply of these oils is limited so other fuels will be needed.
Other biofuels will also play a role, but the actual impact of biofuels on emissions reductions can vary widely depending on their source, says Praveen Bains, a biofuels analyst at the International Energy Agency. Also, biomass sources such as agricultural waste will not be sufficient to power global flight.
The aviation industry also relies on technology such as synthetic kerosene for alternative fuel. This technology uses electricity to convert carbon dioxide into fuel planes can burn. At least half the alternative fuel supply in ICCT projections comes from this technology. Although some of the process is already being done industrially, there are big questions regarding the technology and its future costs.
In order to make up the rest of the emissions cuts needed to stay below 2 degC by 2050, airlines will need to improve both technical efficiency (for example, how much fuel a plane burns per mile) and operational efficiency (how full flights are). Demand will likely slow down due to people moving less or switching to high-speed trains. “It’s going take a lot work,” Graver states. “I don’t want people thinking that it’s a hopeless case and that nothing’s going down.” But we need to take action now.”
I’m a journalist who specializes in investigative reporting and writing. I have written for the New York Times and other publications.