On some flights, emissions rose to nearly 900 grams
per passenger per kilometre, revealing how inefficient aircraft choices and low
passenger loads can sharply increase the aviation sector’s carbon footprint.
Researchers analysed data from over 27 million commercial flights in 2023, covering over tens of thousands of cities and nearly 3.5 billion passengers.
By comparing aircraft types, seating layouts, and the number of passengers, the researchers were able to pinpoint where the biggest, most efficient changes could be made using existing technology.
The analysis shows that aviation’s
climate impact is not only about how much people fly, but about how efficiently airlines
operate each flight.
One of the clearest findings is that many airlines
continue to fly older, less fuel-efficient planes on busy routes, even when
newer and cleaner models are available.
Assigning the most efficient aircraft to high-demand routes could cut emissions by around 11 per cent immediately, without changing flight schedules or reducing travel demand.
Seating configuration also matters.
Aircraft with large premium cabins use more space per
passenger, raising
emissions per seat. Flights with mostly economy seating tend to be significantly more
efficient.
In addition, many planes take off with empty seats.
Increasing average passenger load factors closer to 95 per cent would sharply
reduce emissions per traveller.
“Efficiency-focused policy could swiftly reduce aviation emissions by more than half, without reducing flight numbers or waiting for future fuels,” said Dr Milan Klower, co-author of the study.
Aviation is one of the fastest-growing sources of greenhouse gas emissions, and long-term solutions such as sustainable aviation fuels and electric aircraft are still years away from large-scale use.
This research shows that meaningful climate
action in aviation does not have to wait for future technology.
By making smarter operational choices today, ranging
from aircraft deployment to seating layouts, airlines could deliver deep
emission cuts within this decade, while keeping global air travel moving.
Tags: Aviation flights carbon dioxide
