UK Climate Advisers Say Heathrow Expansion Requires Airlines to Pay for Carbon Removal

Heathrow airport should be allowed to expand only if airlines pay for the removal of carbon dioxide from the atmosphere, the government’s climate advisers have said.

Building a third runway and new terminals, as some in government want to do, would breach the UK’s carbon budgets and make reaching net zero by 2050 impossible, on current policies, according to the Climate Change Committee.

The “only way” to manage such expansion within the UK’s climate commitments was for the aviation industry to become more efficient, use an increasing proportion of “sustainable aviation fuels” (SAF) in place of fossil fuels, and pay for the permanent removal and storage of carbon from the atmosphere.

Nigel Topping, the chair of the CCC, said: “The government cannot expand Heathrow airport without requiring the aviation industry to clean up its emissions. Therefore, the government should legislate policies that require the aviation industry to fully address all of their emissions by 2050, either directly or by purchasing engineered removals. The polluter-pays principle must apply.”

In a report to the government on Wednesday, the CCC found that the costs of SAF and carbon removal would probably be passed on to passengers by airlines, adding an estimated £150 to the price of a return flight to Alicante by 2050, or about £400 to the price of a flight to New York. These costs would be phased in gradually over 25 years.

But campaigners rejected the CCC’s plan of relying on nascent technologies to wipe out the impact of an expansion that would commit the UK to much higher emissions for decades, and called on ministers to halt all airport expansion.

Tony Bosworth, campaigner at Friends of the Earth, accused the CCC of “pulling its punches”, pointing to recent research by the Tyndall Centre that found SAF and carbon removals were unproven and unlikely to ramp up in time to the extent needed to justify airport expansion.

“The CCC should have made it crystal clear: there is no plausible way to expand Heathrow without wrecking the UK’s climate targets,” he said.

Frequent flying is overwhelming skewed towards the wealthy. In any year, only about half of people in England take a flight abroad, while about 80% of all flights abroad were taken by people who took two or more flights – about a quarter of the population. Frequent flyers – those who took five or more return flights abroad in 2024 – made up only 5% of the population, but accounted for a third of all flights.

Those in the highest income group took 38% of all flights abroad – four times as many flights as those in the lowest income group, according to the National Travel Survey of England in 2024.

The CCC said policies to force airlines to take responsibility for cleaning up their emissions should take these inequalities into account, but stopped short of recommending a frequent flyer levy.

The rise in demand for flying since the Covid pandemic threatens to raise carbon emissions around the world. Separate research by the campaign group Transport&Environment has found that planned expansions at 20 of Europe’s biggest airports, including Heathrow, would breach EU and national carbon limits, even if the planes using them were more efficient and partly powered by sustainable aviation fuel.

James Richardson, director of analysis at the CCC, said the past three decades of growth in the aviation industry and the likely increase in future demand meant it was “too big” to rely on other sectors to cut their emissions, allowing flying to take up more space within the UK’s carbon budgets. Aviation now produces more carbon than the UK’s electricity generation, and passenger demand has nearly tripled from 100 million passengers in 1990 to 300 million in 2025. It now makes up 9% of the UK’s emissions, and will be one of the two top emitting sectors, along with agriculture, by 2050.

A spokesperson for Heathrow said: “Heathrow expansion cannot be a choice between economic growth and net zero – it must deliver both. The CCC’s assessment does not change this and acknowledges that the key solutions exist today. We will continue working with government and partners across the aviation sector to ramp up today’s proven technologies, while examining options for how the billions of pounds passengers already pay in carbon taxes can be used to support this.”

But Tim Alderslade, chief executive of industry body Airlines UK, claimed the CCC’s approach was not affordable and would “put holidays out of reach for millions, turning the clock back to a time when flying was the preserve of the rich”. He said: “You can’t solve the climate crisis by pricing Britain out of the skies. The answer is affordable SAF – already cutting emissions since the mandate began – airspace reform by 2035 for more direct routes and scaled-up carbon removals.”

The government is not obliged to follow the advice of the CCC, which was set up under the 2008 Climate Change Act to draw up five-yearly carbon budgets. Topping said that if consent was granted to Heathrow without legislation in place to force the industry to clean up its emissions, “there will be a big red light flashing” in the CCC’s report to parliament.

Responding to the CCC’s findings, a spokesperson for the UK’s Department for Transport said: “Any expansion proposal [for Heathrow] would need to align with our net zero targets. We’re investing £219m in sustainable aviation fuel production and a further £43m in cleaner technologies to support greener aviation, while expansion could deliver around £40bn to the economy and support up to 60,000 local jobs.”