Optimising the cabin: Can denser seating drive down flight emissions?
August 11, 2025
Data from Cirium’s EmeraldSky tool shows that more efficient seating arrangements can significantly reduce aircraft carbon emissions, offering a quick alternative for airlines to meet their net-zero by 2050 commitment.
While increasing seat density might not appeal to passengers on the face of it, such measures can reduce personal carbon emissions. Smart seating solutions can mean that comfort is not noticeably impacted.
How seat density impacts airline CO2 emissions
Cirium’s analysis shows that some airlines have already achieved reductions in CO2 emissions per available seat-kilometre (ASK) by redistributing the fixed space inside the cabin more efficiently.
Once an aircraft is airborne, its fuel consumption is largely fixed. The more seats available to share the fuel load, the lower the per-passenger emissions.
The notion that higher seat density in the cabin can reduce the personal carbon footprint of each passenger is not new. Previous studies conducted by the International Council on Clean Transportation (ICCT) have shown that airlines operating the same aircraft on the same route can make their flights more sustainable by adding seats.
An ICCT study published in 2018, examining the transatlantic market, found that:
“Aircraft fuel burn was found to be the most important driver of fuel efficiency overall, explaining almost 40% of the variation in airline fuel efficiency across carriers, followed by seating density, which accounted for one-third of the variation. Freight share and passenger load factors were relatively less important.”
Cebu Pacific reduces carbon emissions by 25% with denser seating on A330-900neo
Cirirum cites one outstanding example of possible environmental gains in Cebu Pacific’s A330-900neo. The airline’s cabin configuration accommodates 459 seats—138 more than the global average for this aircraft type.
Despite operating the same aircraft, on the same route, with the same engines as other carriers, Cebu Pacific has seen a 25% reduction in its environmental footprint, simply by carrying more passengers.
Rethinking aircraft efficiency: Opportunities and trade-offs
Sustainability in aviation is often associated with new technologies, with their associated long research and development timelines, and the supply of Sustainable Aviation Fuel (SAF).
But new types of propulsion for large commercial jets are still on the drawing board. SAF supplies are woefully low, still under 1% of the global fuel demand, and with few signs of significant increases in the short term.
However, airlines can take immediate steps to fly more sustainably by rearranging their cabins. The question remains whether the airlines’ customers will value greener flights over greater legroom.
In recent years, airlines have been adding more premium space to their aircraft, responding to customer preferences.
The cabin layout decision will hinge on each airline’s brand positioning. It is easier for budget airlines to arrange the cabin space for the lowest individual carbon footprint than it would be for a full-service carrier.
In the end, customers will decide. Airlines will need to balance the stated desire for sustainability with the actions of their customers at the time of booking. If passengers continue to prioritise their comfort over their carbon footprint, then airlines will design their cabins accordingly.
From a sustainability perspective, however, the results are clear: emissions performance is not just driven by the type of aircraft an airline operates but by how it is configured.
Cirium’s data suggests that smarter seating arrangements can make a significant difference in reducing aviation’s carbon footprint. Airlines that rethink the cabin space, in favour of greener layouts, could be better positioned to meet their Net Zero targets.
