Global aviation emissions could be reduced by between 50% and 75% through the combination of three strategies to boost efficiency, a new study has found.
These include flying only the most fuel-efficient aircraft, switching to ‘all-economy’ layouts, and increasing passenger loads, the study, which was published in Communications Earth & Environment, found.
In producing the study, researchers analysed more than 27 million commercial flights that took place in 2023, carrying close to 3.5 billion passengers and covering around 26,000 city pairs.
Aircraft type
As it found, emissions production varied greatly depending on aircraft type, seating configuration, and passenger occupancy, with some routes producing nearly 900 grams of CO₂ per kilometre for each paying passenger, and others producing as little as 30 grams of CO₂ per kilometre.
On average, aviation emissions stood at 84.4 grams of CO₂ per kilometre for each paying passenger, it noted.
As the study found, the use of more fuel-efficient aircraft played a key role in reducing the emissions per passenger – transitioning to the Boeing 787-9 for long-haul flights and the Airbus A321neo for short and medium-haul routes, the researchers noted, could reduce fuel use by 25% to 28%.
“While economically and practically unfeasible to replace all older aircraft short term, this analysis shows the potential more efficient aircraft have in comparison to other efficiency gains,” commented Dr Milan Klöwer, Department of Physics, University of Oxford, and co-author of the report.
“Realistically, this would be a long-term transition – one that could be promoted by policies that reward efficiency, so that the most efficient aircraft are favoured whenever replacement decisions are made.’
Seating configurations
Elsewhere, seating configurations made a difference, with business and first-class seats found to be up to five times more CO₂-intense than economy class seats, simply because fewer passengers are carried.
A switch to an ‘all-economy’ layout could potentially reduce emissions by between 22% and 57%, the researchers claim.
Passenger occupancy
Allied to this, increasing passenger occupancy could also have a positive impact. Aircraft occupancy levels stood at 79%, on average, in 2023, with the researchers noting that raising average occupancy to 95% could reduce emissions by a further 16%.
“Efficiency-based policies have a great potential to curb aviation emissions, and can be in airlines’ own economic interest,” added Professor Stefan Gössling of Linnaeus University, the report’s lead author. “But the reality is that many airlines continue to fly with old aircraft, low passenger occupancies, and growing proportions of premium-class seating.”
The study was based on data from Airline Data, the International Civil Aviation Organization, and the International Air Transport Association. Read more here and here.
