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Our comment on the Airports Commission appraisals of Heathrow and Gatwick runways

11th November, 2014


The Aviation Environment Federation (AEF) believes the Airports Commission paints a misleading picture about the net benefits of expansion by failing to fully consider the environmental costs in the economic appraisal of a new runway at either Heathrow or Gatwick. This raises serious concerns about the validity of the consultation’s claims.

Commenting on the published appraisals, Deputy Director, Cait Hewitt said:

“Environmental costs are being treated as second class concerns to economic benefits. The Airports Commission lauds the economic benefits of expansion but the failure to factor in full carbon costs is a massive gap in their analysis, making their figure of overall benefits to the economy irrelevant.

“Growing emissions at Heathrow or Gatwick would negatively impact regional airports by requiring them to be capped at below today’s levels of passengers and that is not considered in the Commission’s analysis.”

The Airports Commission’s analysis of the wider economic impact of expansion fails to reflect the full carbon costs. These costs, according to the Commission would ‘dominate’ the economic appraisal of the schemes[1]. The Airports Commission also acknowledges that it hasn’t considered what policies would be needed to restrict growth of emissions to the level they use in each stage of their analysis (the carbon capped scenario).

Our research[2] highlighted that regional airports would have to be capped at below today’s levels of passengers to accommodate growth from a new runway but this constraint was not considered in Commission analysis despite the fact that an expanded Heathrow or Gatwick would mean the two airports would take up two thirds of the total emissions available to aviation[3].

On air quality which would have ‘significantly adverse’ impacts at Heathrow and ‘adverse’ at Gatwick according to the Commission, posing risks to legal limits beyond 2030, Cait commented:

“All political parties talk the talk on air pollution, but with air quality in both London and the wider South East region already breaching legal limits, adding a new runway to the mix would be hard to justify.”


More information: Contact James Lees, Research and Communications Officer, Aviation Environment Federation on 020 7248 2223 /

About the Aviation Environment Federation: We are the only national UK NGO campaigning exclusively on the environmental impacts of aviation. We recently co-ordinated the major national environmental NGOs, including Greenpeace, WWF, Friends of the Earth and RSPB in developing a manifesto for sustainable aviation, link here:

[1] Commission’s statements taken from para 2.41 Airports Commission Consultation Document
[2] Our report, Implications of South East airport expansion for regional airports is available here:
[3] Consultant report for Airports Commission, available here: Annual emissions from an expanded Heathrow would be 20.5 Mt CO2 per year, while baseline for Gatwick is 3.9 Mt CO2. Giving annul emissions of 25 Mt CO2 per year. 66.6% of the 37.5 Mt CO2 a year allowed under Climate targets–assessment.pdf