CCC: Heathrow expansion could push flights to ‘80% of UK emissions by 2050’
Aviation is on track to be responsible for 80% of the UK’s carbon dioxide (CO2) emissions by 2050, according to the Climate Change Committee (CCC).
Emissions from flying have more than doubled since 1990 – driven by rising passenger numbers – even as the climate impact of every other sector in the UK economy has fallen.
The UK does not have “credible” policies in place to reverse this trend of rising emissions, says the CCC in new advice to the government on future aviation policy.
The government has signalled its support for expanding Heathrow, the nation’s largest airport, while relying on “techno-fixes” such as “sustainable aviation fuels” (SAFs) to cut emissions.
Yet, even without Heathrow expansion, the CCC says aviation emissions are on track to be higher in 2050 than they are today – reaching 38m tonnes of CO2 (MtCO2).
As the chart below shows, this would account for most of the remaining CO2 from the UK economy, all of which would need to be removed from the atmosphere in order to meet the legal target of net-zero emissions.
Expanding Heathrow would add another 2.4MtCO2 in 2050, amounting to around 5% of all the UK’s emissions. (This would increase to 4.5MtCO2 when expansion is complete in 2054.)

With a final decision on Heathrow expansion expected by 2029, the government asked the CCC for its advice on whether the plan is compatible with the UK’s climate targets.
The CCC has concluded that the UK simply lacks sufficient policies to reduce aviation emissions and “expanding Heathrow would compound the problem”. In a press briefing, CCC chair Nigel Topping told journalists:
“The UK does not currently have a credible plan to reduce [aviation emissions] in line with net-zero, so that creates a serious challenge for meeting our climate commitments.”
The “jet-zero strategy”, launched by the previous Conservative government in 2022, set out plans to cut aviation emissions. However, the Labour government has since accepted that the strategy’s expectations for SAFs, electric planes and fuel-efficiency improvements were unrealistic.
The CCC says a “credible and robust net-zero policy framework for aviation” should be set out in a revised strategy, which is planned for 2027. Only then could Heathrow expansion be aligned with the net-zero goal, adds the committee.
As part of this new strategy, the CCC says the “aviation sector needs to take responsibility for its emissions”. It says policies should be designed based on the “polluter pays” principle, requiring the aviation industry to fund its own SAFs and CO2 removal.
Specifically, the committee says funding will be needed for “engineered removal” technologies, such as direct air carbon capture and storage (DACCS).
These technologies are currently “not yet available at the scale required”, but are vital for the kind of permanent CO2 removal needed to mop up aviation emissions, says the CCC.
(“Natural solutions” such as tree planting are the other main way CO2 is expected to be removed from the atmosphere. However, the CCC envisages these removals offsetting the remaining methane emissions from livestock agriculture in the UK, whereas it says “engineered removals” would be required to remove and store CO2 from flights.)
The CCC acknowledges that placing decarbonisation costs on airlines would likely lead to higher ticket prices. It estimates that this could mean an increase, in 2024 prices, of around £150 for a return trip to Alicante, Spain, and £400 for a return trip to New York by 2050.
However, it says this is preferable to a public spending approach, which would result in the roughly 50% of the population who do not fly paying for flight-related CO2 removals.
In addition, the committee notes that higher costs would help to manage demand for flights, which would otherwise be expected to increase considerably over the coming decades.