Heathrow expansion has no credible pathway within the United Kingdom’s climate commitments under current policies, the Climate Change Committee (CCC) said on 16 September 2026. The independent watchdog advised that expansion could only be consistent with the UK’s carbon budgets and 2050 Net Zero target if ministers require the aviation industry to reach zero emissions by 2050.
The advice, requested by the government, feeds into the draft Heathrow Expansion National Policy Statement — the planning framework for a third runway at one of the world’s busiest airports, which Labour backed in 2025 as a growth project.
FAKTA
- Finding: No credible pathway for Heathrow expansion within UK climate commitments under current policies (CCC, 16 September 2026).
- Condition: Expansion could only fit if ministers require the aviation industry to reach zero emissions by 2050, through direct emissions cuts and engineered removals.
- Context: UK aviation emissions have more than doubled since 1990, while economy-wide emissions have halved; Heathrow is responsible for around half of the industry’s emissions.
- The 2050 pathway: Engineered removals 36%, lower demand growth 24%, efficiency 20%, sustainable aviation fuel 20%.
- SAF reality: Sustainable aviation fuel accounts for less than 1% of global jet fuel use and costs several times more than conventional fuel.
- Climate test: The CCC says the climate test in the draft expansion statement should explicitly include the 2050 Net Zero target.
An industry without a credible plan
“Emissions from flying are projected to rise, even without Heathrow expansion, and the UK does not currently have a credible plan to bring them down,” said Nigel Topping, the committee’s chair. “Heathrow expansion is not currently compatible with the UK’s Net Zero target. Government needs to ensure that the aviation industry takes responsibility for the emissions it creates and bears the costs of decarbonisation. Those conditions do not exist today.”
“Every tonne of greenhouse gas emissions makes those impacts worse,” Topping added.
The numbers behind the advice
The committee’s 68-page report forecasts that under existing policy, UK aviation emissions would not fall at all from 2025 levels by 2050 — rising from 37 MtCO2e in 2025 to 39 MtCO2e in 2050. Expanding Heathrow would add 0.4 MtCO2e in 2040, rising to 2.4 MtCO2e in 2050 and 4.5 MtCO2e when expansion is complete in 2054.
The total impact would increase whole-economy residual CO2 emissions by 6.9% of expected 2050 levels, the report estimates.
The polluter-pays pathway
The CCC’s net-zero aviation pathway is built on the polluter-pays principle: in 2050, engineered removals would account for 36 per cent of the emissions reduction, lower demand growth 24 per cent, efficiency improvements 20 per cent and sustainable aviation fuel 20 per cent — with industry paying for SAF and engineered removals. The committee also called for a 25-year strategy for net-zero aviation and contingency plans in case key technologies fail to scale.
What happens next
The committee recommended legislation requiring the industry to address all of its emissions by 2050, either through greater sustainable aviation fuel use or engineered carbon-removal credits. A Department for Transport spokesperson said the government would carefully consider the advice, noting investment in SAF production and that expansion would need to be in line with net-zero targets.
