Heathrow’s third runway won’t improve London’s air quality

Is Rachel Reeves really correct that her new-found enthusiasm for a third runway at Heathrow would be consistent with the government’s net zero targets and other environmental policies? Over the weekend she argued that a third runway would be good for air quality over London because it would mean fewer planes circling over the capital. She also asserted that ‘sustainable aviation fuel is changing carbon emissions from flying’, and that ‘there’s huge investment going on in electric planes’.

It isn’t clear where Reeves sourced her evidence that a third runway could actually improve air quality, but that certainly wasn’t the conclusion of a 2017 study by consultants WSP commissioned by the Department of Transport. The study found that Britain could still conform with EU air quality targets by 2030 if a third runway was built, but the project would act as a drag anchor, countering the effect of improvements such as cleaner and efficient engines.      

What about sustainable airline fuel (SAF)? From this year – in accordance with the previous government’s Jet Zero strategy – airlines are under a mandate to use a minimum of two per cent SAF mixed in with normal jet fuel (kerosene).