The construction of a third runway at Heathrow Airport has once again become a hot topic of debate. The Supreme Court lifted a ban on this megaproject in December 2020, despite the heavy opposition of local residents and climate protestors. A large number of analysts believe that the scheme needs to go ahead to satisfy the anticipated demand for air travel after the end of the Covid-19 pandemic, to boost the UK’s economy, and to create a mega hub that could compete with other European airports like Paris’ Charles de Gaulle or Amsterdam’s Schiphol.  Those opposing the project are concerned about the environmental impact, in addition to how much money the government will spend on the construction itself. This article will explain why the expansion is such a controversial issue.


Why a third runway?

Heathrow is both the largest and busiest airport in the UK, primarily serving London’s metropolitan and surrounding areas. Many travelers have even dubbed it ‘the gateway to Britain.’ The airport acts as a connection hub for regional and international passengers and as a result it is credited with boosting the nationwide economy. In 2019, the airport handled a record 80.8 million passengers and around 450,000 flight movements, which are expected to increase in years to come (after the end of the Covid-19 pandemic, of course).

Due to this rapid growth, there have been many proposals by the UK government since 2006 to build a third runway as a way of coping with rising air traffic. There were many discussions regarding where the new runway will be constructed to mitigate disruption to local communities, the environment, and current Heathrow flight paths. The decision was eventually made to expand the airport into the northwest, where the third runway and possibly a Terminal 6 will be built.


Arguments for a third runway:

The project was overwhelmingly supported by airlines, trade unions, and certain businesses, especially those in the transport and logistic sectors. They argued that a third runway:

  • Will boost the economy: Expanding Heathrow will unquestionably attract more passengers, both leisure and business. This will allow London and the country as a whole to compete with other European cities – like Amsterdam, Frankfurt, and Paris – for business investments and an increased role in the global financial sector.
  • Increase connectivity: Heathrow is a major European hub for both regional and long-haul flights and more than 50% of passengers use the airport to board a connecting flight. An expansion will further increase this figure.
  • Reduce flight congestion: Currently (even during the pandemic), aircraft are only allowed to operate between 4.30 am and 11 pm to reduce disruption to the local community. It has been suggested that a third runway will increase Heathrow’s resilience to disruption, and so reduce emissions from aircraft waiting to land prior to operation hours.
  • Creating job opportunities: The construction of a third runway will allow more jobs to be created.

Arguments against a third runway:

Despite the benefits that expansion could bring, there are concerns among environmental campaigners, certain politicians, and local residents. They argue that a third runway will lead to:

  • Rising greenhouse gas emissions: Environmentalists argue that expanding Heathrow will increase carbon dioxide emissions, the leading cause of global warming. According to government estimates, the construction of a third runway will generate around 210 million tons of CO2 and cause substantial damage to the climate.
  • Increasing noise and air pollution: The expansion of Heathrow will lead to an increase in the number of flights that are landing and taking off from the airport, which in turn will lead to more noise pollution for those living nearby.
  • Less money being spent elsewhere: Many people believe that Heathrow’s third runway is an unnecessarily expensive project and have argued that the government should spend its money elsewhere; the health and education sectors are especially in need of more funding.
  • Community destruction: The construction will lead to the demolition of surrounding buildings, such as houses, churches, and even local graveyards. The diagram below gives some indication of which villages will be directly affected by the expansion:

Are there any alternatives?

If expanding Heathrow proves to be too divisive a project, there are alternatives that the government have considered instead:

  • Better usage of existing capacity: Airlines are advised to use wide-body aircrafts (such as Airbus A380’s or Boeing 777’s), which can transport more passengers and cargo. Although this is a short-term strategy, it will probably free some airport slots and relieve congestion.
  • Increase usage of other London airports: London has six official airports. There have been proposals to further utilise these facilities as they are further away from the city center and will be easier to expand. Both Gatwick and Stansted could be expanded without much destruction to the environment or local communities. However, this would be more inconvenient for passengers needing to transfer between airports.
  • The ‘Thames Estuary Airport’: Multiple proposals have been put forward for a ‘Thames Estuary Airport’, which would serve as a new hub for London. This airport would be able to operate 24 hours a day and would be easy to expand if necessary. Furthermore, construction of this airport would not incur as much environmental or building damage as a third Heathrow runway. That being said, there are concerns that this proposal would threaten jobs at Heathrow and would be more expensive in the long run.
  • Reduce regional air travel and increase rail transport: There are government proposals to reduce the number of domestic flights by improving rail networks, which may make a third runway obsolete.

What next?

It is currently unknown whether Heathrow’s third runway will go ahead or not, and a large number of people will be dissatisfied regardless of the final outcome. But there are two important questions: can Heathrow keep its status as a major global hub without the addition of a third runway? And is the government willing to risk the destruction of both the environment and local communities in order to see the project through?