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Challenging airport expansion

For the latest news and updates on recent and current airport expansion plans, visit our Airport Tracker.

In 2019 the requirement for the UK to achieve net zero emissions by 2050 (with all emissions by that date needing to be balanced by greenhouse gas removals) became law. In April 2021, the Government announced that it would set an interim target to reduce emissions by 78% below 1990 levels by 2035, and that it would accept the advice of its expert climate advisory body, the CCC, that, for the first time, the Sixth Carbon Budget should include international aviation and shipping emissions. 

The CCC Sixth Carbon Budget report of December 2020 also included advice and recommendations on the steps needed to put the aviation sector on a pathway to net zero, including limiting demand growth to around 25% above 2018 levels by 2050. Since the maximum level of passenger demand compatible with achieving net zero aviation emissions can already be accommodated with existing runways and terminal capacity, CCC argued, there should be no net increase in the UK’s airport capacity. Since then, the CCC’s 2023 Progress Report to Parliament stated that “There has been continued airport expansion in recent years, counter to our assessment that there should be no net airport expansion across the UK. No airport expansions should proceed until a UK-wide capacity management framework is in place to assess annually and, if required, control sector CO2 emissions and non-CO2 effects.”

Contrary to this advice, the Government’s Jet Zero Strategy One Year On published in the summer 2023, forecasts passenger increases of 52% above 2018 levels, more than twice the 25% growth allowed for in the Climate Change Committee’s net zero modelling. AEF’s view is that this is a high-risk strategy that puts emissions targets at risk. The Government’s support for ‘sustainable airport growth’ also continues to rely on policies – the Airports National Policy Statement and Making Best Use of Capacity – published before net zero by 2050 became law. 

Keen to make the most of this green light for expansion, a large number of airports have submitted, or will submit shortly, their plans to grow, and several have already received permission despite local opposition: applications for expansion at both Bristol and Stansted were turned down originally by their respective local authorities on the basis, in part, of their likely impacts on climate change, only to see these decisions overturned by the Planning Inspectorate.

The cumulative effect of these proposals on climate change, would, if they are all approved, be significant.


Our analysis shows that if all airport expansions are allowed to proceed it could result in up to 9Mt of extra CO2 per annum by 2050 if the Government’s optimistic forecasts for the scaling of alternative aviation fuels are not met. This is additional to the 18.7 million tonnes of CO2 that the industry is still expected to emit in 2050 and which will need to be balanced by large-scale investment in carbon removals to meet net-zero targets.

A moratorium on future airport expansion would be one of the more straightforward policy measures for the Government to put in place, as a first step towards bringing aviation’s environmental impacts to within acceptable levels. AEF, together with fifteen community groups, wrote to the Secretaries of State for Transport and Housing, Communities and Local Government in May 2021 recommending such a moratorium. You can read our letter here. A year later, in May 2022, AEF joined up with several UK environmental NGOs to issue a similar recommendation.


What do we want to see?

  • The Government should recognise and implement the CCC’s advice on no airport expansion without a UK-wide airport capacity management framework in place
  • There should be a moratorium on all current airport expansion plans (until and unless these can be shown to be compatible with the UK’s net zero plans).
  • Local and regional authorities should be both encouraged and empowered to consider the impact of airport expansion on local climate change targets.