The UK Civil Aviation Authority (CAA) has unveiled a new set of guidelines aimed at standardising how greenhouse gas (GHG) emissions data is presented to air passengers during the booking process. The framework targets airlines, travel agents and flight comparison platforms operating flights to and from UK airports.
If adopted, the approach would see carbon emissions information displayed consistently across booking channels for all relevant flights, with the regulator setting April 2027 as its target date for broad implementation. The initiative reflects growing regulatory and consumer demand for clearer insight into the environmental impact of air travel.
‘Consumers can make more informed travel choices by accessing clear, consistent and accurate emissions information about the flights they book’, the CAA said. While some emissions figures are already available to passengers, the authority noted that ‘this information, which is already available on some flight comparison websites and in other sectors such as rail, should be standardised and comparable.’
The proposal arrives against a backdrop of increasing pressure on the aviation industry to demonstrate progress towards its climate commitments. Aviation has pledged to achieve net-zero emissions by 2050, with international efforts coordinated through the International Civil Aviation Organisation’s Carbon Offsetting and Reduction Scheme for International Aviation (CORSIA).
CORSIA establishes a global framework for limiting emissions growth from international flights and includes a near-term objective to reduce emissions by 5% by 2030 through the uptake of sustainable aviation fuel (SAF). From next year, the scheme will enter its mandatory phase, requiring participating airlines to compensate for emissions exceeding 85% of a 2019 baseline. Compliance can be achieved either through the use of SAF or the purchase of approved carbon offsets.
As these obligations come into force, the CAA argues that comparable and reliable emissions data will play an increasingly important role in helping passengers understand the climate impact of their travel choices. Although many booking platforms already display emissions estimates, the regulator has raised concerns that inconsistent methodologies undermine their value.
To improve accuracy and comparability, the CAA is encouraging emissions calculations that incorporate a wider range of variables, including aircraft and fuel type, seat class, passenger load factors, occupancy rates and cargo distribution. The objective is to provide more granular carbon data that enables meaningful comparisons between flights.
The authority plans to assess uptake across airlines and booking platforms in 2027 and will publish a review of its findings. Should voluntary adoption fall short, the CAA has signalled that it may explore the introduction of mandatory reporting requirements.