Air quality could delay expansion at Heathrow

Air quality could delay expansion at Heathrow

A new report by a leading global environmental consulting firm has found that Heathrow’s expansion plan could lead to breaches in EU and UK air quality laws.

The report - by Environmental Resources Management and Clear Air Thinking – found that, should the Government approve Heathrow’s expansion plans, it would be doing so without any certainty that the UK’s legal obligations under the 2008 EU Air Quality Directive and the UK implementing regulations could be met.

Air quality is a critical issue in the debate over where the UK’s next runway should be built and has been a major factor in the vehement opposition to previous attempts by Heathrow to expand.

The area around Heathrow already breaches EU air quality limits and a recent DEFRA report said it was not expecting compliance with EU NO2 levels in the Heathrow area until the early 2030’s. DEFRA’s analysis does not even take into account the additional pollution that would be created if Heathrow built a new runway.
London has some of worst NO2 spots in Europe but, in contrast, Gatwick has never breached EU and UK annual air quality limits and the airport has committed to maintaining this record if it built a second runway. This can be done as Gatwick is located in a largely rural, sparsely populated area, and also has one of the cleanest aircraft fleets in Europe.

ERM found Heathrow has not provided any evidence that expansion at the airport would not increase NO2 levels above these legal standards or delay attainment of the limits. Nor has Heathrow included any quantification on how the airport’s proposed pollution mitigation measures – including a road congestion charge – would solve this issue.


Congested road traffic flows are a major influence on NO2 emissions and the report points out that construction traffic and major changes to the highway network will further reduce the likelihood of compliance.

Stewart Wingate, Gatwick CEO, said:

“The UK needs a new runway but the decision about where it should be built must take into account the environmental impact it would have, especially in terms of noise and air quality.

“The air quality around Heathrow is critical to the airport’s development plans - if legal standards cannot be met around Heathrow, then expansion there would be unlawful.

“Gatwick has never breached legal air quality limits and would still operate within these standards with a second runway. Gatwick’s expansion plans strike the right balance between delivering the extra airport capacity, while taking the right steps to protect the environment.”