Global greenhouse gas emissions from aviation could be reduced by between 50% and 75% by using only the aircraft that consume the least fuel, eliminating first class or business class and increasing the number of passengers per flight.
The conclusion comes from a study published in the journal Communications Earth & Environment, conducted by researchers from Sweden, Denmark, the United Kingdom and Germany. The team says that the global aviation sector could already cut about 11% of its emissions if it strategically uses, on routes already flown, the most fuel-efficient aircraft that airlines already own.
The work involved the analysis of more than 27 million commercial flights in 2023, covering nearly 26,000 routes and involving around 3.5 billion passengers. The researchers say the variation in emissions between flights can be substantial, with some routes producing about 900 grams of CO2 per passenger per kilometer, a value about 30 times higher than the most efficient routes, which are around 30 grams of CO2 per passenger-kilometer.
According to the estimates, in 2023 global aviation average emissions were 84.4 grams of CO2 per passenger per kilometer. At a time when climate change mitigation is sought, where reducing greenhouse gas emissions is indispensable, the article’s authors suggest that airlines use only the most fuel-efficient aircraft, do away with first-class or business-class zones to create more seats, and increase the passenger-carrying capacity to 95%.
The team says that simply using only the most efficient airplanes already allows significant reductions in emissions. Additionally, they point out that replacing all aircraft with the most efficient models would result in fuel savings of between 25% and 28%.
In 2023, the analyzed flights had an average passenger load factor of 79%, ranging from 20% to 100%. The researchers say that raising this average to 95% would help reduce an additional 16% of emissions.
Applying the three measures globally, the team calculates that emissions could be reduced by more than half.
“Efficiency-based policies have great potential to reduce aviation emissions and may be in the airlines’ own economic interest,” the note states.
“But the reality is that many airlines continue to operate older aircraft, low passenger load factors, and increasing shares of seats in the premium cabin,” they note.
