Three strategies to improve airline fuel efficiency could reduce global aviation emissions by at least half, according to a new analysis.
The aviation industry is responsible for about 4% of global greenhouse gas emissions. Discussions of how to reduce that often focus on emerging and uncertain technologies like electric aircraft, hydrogen, and sustainable aviation fuels. Others advocate that people should simply fly less.
The new study shows how to substantially reduce emissions without waiting for new technologies or constraining people’s ability to fly.
“I assumed that air transport is already efficient, as airlines often say this,” says study team member Stefan Gössling, a professor at Linnaeus University in Kalmar, Sweden who studies tourism and transport sustainability. “I was surprised by the very large potential to reduce fuel use just by organizing flights more efficiently.”
Gössling and his collaborators sliced and diced a massive trove of data on more than 27 million commercial flights that carried almost 3.5 billion passengers in 2023. They analyzed aviation emissions by aircraft, airline, airport, and routes between more than 26,000 city pairs.
On average, moving one airline passenger one kilometer by air generates 84.4 grams of carbon dioxide emissions, the researchers found. But this figure conceals huge variations in efficiency.
Flying between some cities results in nearly 900 grams of carbon dioxide emissions per passenger kilometer, for example, while other routes yield just over 30 grams – a nearly 30-fold difference. Depending on the aircraft model, the climate impact of flying varies from 60 to 360 grams of carbon dioxide per passenger kilometer.
The researchers calculated the effects of three different strategies for reducing aviation emissions. First, an airplane fleet composed of only the most efficient models currently in use (the Boeing 787-9 for long-haul flights and the Airbus A32/neo for shorter hops) would cut average emissions by 25-28%.
Next, the researchers considered the effects of rejiggering the seats inside airplanes. “Air transport is inefficient, specifically because such a large share of space in aircraft is devoted to very few seats in premium class,” Gössling says.
Business- and first-class seats are up to five times more carbon intense than economy seats, but switching to an all-economy layout could slash emissions by a further 22-57%.
Finally, maximizing the number of passengers by increasing average aircraft occupancy to 95% from the current average of 79% would shave an additional 16% off airline emissions.
The three strategies combined could reduce global aviation emissions by about 50-75%, the researchers found. In other words, airlines could be using half the amount of fuel they currently do to transport the same number of passengers the same distance.
Not all of these strategies would be practical to implement right away – fleet turnover takes time, for example, so airlines can’t just up and switch to the most efficient aircraft. But the findings suggest that climate policies related to aviation should focus less on promoting sustainable aviation fuels, which are “very expensive and very problematic” and must often be subsidized by governments, Gössling says. “It would be much easier to avoid using as much fuel, rather than subsidizing inefficiency.”
Source: Gössling S. et al. “Large carbon dioxide emissions avoidance potential in improved commercial air transport efficiency.” Communications Earth & Environment 2026.
Image: ©Anthropocene Magazine
