Skip to content
Infrastructure blog

The future of UK airport capacity? Insights into Heathrow’s third runway

24 October 2019

ICE has published an insights paper into the costs and benefits of a third runway at London Heathrow Airport. The paper explores the background behind the project, the strategic implications and challenges and the alternatives which could be considered.

The future of UK airport capacity? Insights into Heathrow’s third runway
Heathrow’s third runaway faces a gateway decision within the next year. Image credit: Sebastian Grochowicz/Unsplash

One of the longest-running major infrastructure project debates in the UK could close by the end of the year when the statutory consultation wraps up, with final planning consent potentially decided early next year.

Crowded airspace

Heathrow is one of the busiest airports in Europe, handling 80 million passengers in 2018, and the UK’s only hub airport.

The core argument for a new runway revolves around significantly increasing capacity for commercial, business and freight flights. Spare capacity would also support resilience at an airport where any incident leads to significant delay.

More flights would also increase economic benefits for the UK and opportunities for job creation, unlocking new markets abroad, something particularly important as the UK prepares to leave the EU. This all comes at some cost, however.

The environment

With heightened concern about climate change, and in the wake of recent climate activism on the streets and from young leaders, any economic benefits which might be derived from airport expansion are to be balanced against the impact on the environment.

International aviation is not currently included in the UK’s carbon budgets but are part of the long-term net-zero carbon emissions targets. The contribution of aviation to UK emissions sits at approximately 6%, but they've more than doubled since 1990, while overall emissions have fallen by 40%.

While Heathrow is planning to create carbon sinks around the airport, only 40% of journeys to Heathrow are made by public transport. This has raised local concerns about the impact of road and noise pollution on local communities.

The Committee on Climate Change has recommended that aviation emissions remain at levels equivalent to 2005 in the future. With only moderate fuel efficiency improvements likely in the medium term, expansion at Heathrow might stunt growth at other airports as a consequence.

Are there alternatives?

The Airport Commission’s final report in 2015 considered two alternatives in addition to a third runway at Heathrow, including extending an existing runway to operate as two separate runways, and a second runway at Gatwick.

While both projects are feasible, now and in the future, a second runway at Gatwick could offer slightly more capacity than a third runway at Heathrow, as well as economic opportunities away from more built-up areas.

Improved ground-based connectivity could also take the steam out of plans to build a third runway at Heathrow.

In particular, High Speed Two could expand connectivity for airports in the Midlands and the North. If more people can travel to regional airports more easily, the need for expansion in one place would be lessened.

High-speed rail lines could also compete with domestic flights, freeing up capacity at regional airports across the piece. An ambitious link connecting High Speed One and High Speed Two, if built, could even replace some flights going to the near continent, creating the potential for a European ‘Mega Hub’ connecting London, Paris and Amsterdam.

Final call

Heathrow’s third runaway faces a gateway decision within the next year.

Increasing demand for flights, a growing population and a need for the UK to compete on the world stage makes international connectivity at least as vital as domestic connectivity.

Take-off of this project – and others like it – need sound economic arguments, clear evidence that they'll serve societal wellbeing and that their impact on the environment can be mitigated.

ICE’s insights paper offers a compact resource for all stakeholders with an interest in the project to reacquaint themselves with the key issues.

Read the full paper

  • Policy, at ICE