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Heathrow third runway would leave us last in the global race to tackle aviation emissions

17th July, 2013


Heathrow Airport has today revealed plans for a third runway with options located to the North, North West, or South West of the existing site, increasing flight numbers by more than 50% from the maximum level currently allowed. But official figures show that even without additional runways, emissions from aviation will exceed the maximum level that could be squeezed in under climate change legislation. Adding a new runway would effectively make the targets underlying the Climate Act impossible to comply with.

Heathrow’s defence in relation to emissions rests on a speculative ‘CO2 road map’ drawn up by the aviation industry itself and assuming far more optimistic progress on biofuels and aircraft technology than official forecasts by the Government and the Committee on Climate Change (CCC), the UK’s official climate advisers.  Already, the airport is responsible for significantly more CO2 emissions than any other airport globally – 50% more than the next highest emitter, Dubai (see note 1). A new runway, especially one with a high proportion of long haul flights, would put the UK in a league of its own in terms of aviation emissions.

The airport claims that the numbers of people exposed to noise will reduce over time, despite the huge increase in flight numbers it is proposing. But the measure they use – the 57 decibel contour – has been widely discredited as an adequate indicator of community annoyance. The economic argument, meanwhile, that new flight connections will boost economic growth, is not borne out by independent research (see note 3).

Cait Hewitt, Deputy Director of the Aviation Environment Federation, said:

“Heathrow talks about helping the UK to win the global race. But at the moment, we’re on a race to the bottom in terms of aviation emissions, with Heathrow already responsible for more CO2 emissions than any other airport in the world – 50% more than the next closest ‘rival’, Dubai.

The UK is one of a number of countries trying to push for a global agreement on aviation emissions though the UN. But if we are to have any chance of complying with our own legally binding climate change commitments, a new runway should be out of the question.”


  1. A comparison of emissions from international airports published this year found Heathrow to be by far the highest emitter. See Southgate, D (2013) Aviation carbon footprint: global scheduled international passenger flights 2012.
  2. The CCC recently wrote to the Airports Commission underlining the need for passenger growth to be constrained to no more than a 60% increase over 2005 levels But DfT forecasts indicate that we are on course for a 93% increase, even without the addition of new runways
  3. Research from the independent consultancy CE Delft published earlier this year found that for developed economies, any correlation between the amount of flying and economic activity is a result of increased demand for flying, rather than there being any increase in trade as a result of laying on either additional flights, or flights to new locations, including emerging economies. While it clearly benefits Heathrow for travellers to use it as a hub to travel on to other destinations, there is no obvious benefit to UK businesses in hubbing via Heathrow rather than an alternative European airport.