Airlines and booking firms should give UK customers information about the environmental impact of their flights, the regulator has said.
The Civil Aviation Authority urged booking sites to enable passengers to make “more informed travel decisions” by setting out estimates for carbon emissions for flights landing or taking off from British airports.
New guidance published by the CAA aims to standardise the kind of data already published by some airlines and websites and to make it available at the time of booking so passengers can make comparisons.
The regulator said it would start monitoring and possibly enforcing the new rules after April 2027.
It said the carbon emission data should reflect factors such as aircraft type and fuel use, and take into account the type of seat occupied. It added that this information was already available in sectors such as rail, and a standard framework would help aviation’s ambitions to become net zero for carbon emissions by 2050.
The CAA director, Tim Johnson, said: “Airlines providing understandable and comparable emissions data will enable passengers to make more informed travel decisions. We encourage all airlines and travel companies that advertise or sell flights in the UK which depart from or arrive at UK airports to follow this guidance.”
Emissions per passenger are typically lowest on short-haul, fuel-efficient modern fleets with large numbers packed into economy seats – a fact that has encouraged airlines such as Ryanair and Wizz Air to regularly publicise their CO2 per head figures.
Airlines were broadly accepting of the move during a consultation held by the CAA in 2024, although questions were raised about the limits of the data, with factors such as changes to flight paths, aircraft and bookings all affecting accuracy.
The environmental campaign group Cagne, which was among those lobbying for the change, said the guidance was welcome but it was “imperative that there is transparency” and that consumers could understand the magnitude of emissions released, per passenger per flight.
A spokesperson for Cagne said the airlines should “provide comprehensive data in the simplest form to the consumer in the same way that smokers are told how they are damaging their health by smoking”.
