Heathrow Airport expansion: Supreme Court Appeal hearing on the ANPS. Briefing by Friends of the Earth

The hearing at the Supreme Court of the appeal by Heathrow against the judgement of the Appeal Court, in February took place on 7th and 8th October.  The case is whether the Airports NPS (ANPS) is illegal, because it did not properly consider carbon emissions and the UK’s commitments under the Paris Agreement. Friends of the Earth have explained their arguments, against those of Heathrow. (It is complicated legal stuff …) There is no onward appeal from the Supreme Court.  If any one of the grounds that won in the Court of Appeal remains, and the Supreme Court agrees that the Order made by the Appeal Court should still stand, then the ANPS will remain of no legal effect [ie. not valid or legal] until reviewed. [So the runway cannot go ahead]. The Secretary of State (SoS) for Transport must then consider if the government wish to leave it at that, or review the ANPS policy framework, to amend it. If the SoS does that, s/he will probably need to make changes that materially alter what the ANPS says. Such changes will need to be approved by Parliament following consultation, before the new ANPS can come into force. And if the FoE Strategic Environmental Assessment (SEA) challenge wins, there would need to be a new SEA and a new public consultation.



Heathrow Airport expansion – Supreme Court Appeal briefing, by Friends of the Earth

Briefing prepared by Will Rundle, Head of Legal  – and Katie de Kauwe, Lawyer at Friends of the Earth
5 Oct 2020    (Friends of the Earth briefing)


The historic decision of the Court of Appeal on 27 February 2020 means that the expansion of Heathrow Airport has been halted. Friends of the Earth brought its case against the building of a third runway to protect the climate. Heathrow Airport is already one of the largest emitters of carbon dioxide in the UK. The climate impacts of the airport and a new runway would have been extremely dangerous for people and the planet.

This briefing:

  1. summarises the Court of Appeal result
  2. gives an update on the Supreme Court stage
  3. describes the potential outcomes.

“The legal issues are of the highest importance. The infrastructure project under consideration is one of the largest. Both the development itself and its effects will last well into the second half of this century. The issue of climate change is a matter of profound national and international importance of great concern to the public – and, indeed, to the Government of the United Kingdom and many other national governments, as is demonstrated by their commitment to the Paris Agreement.”

(Court of Appeal judgment, para. 277)

The Judicial Review and Court of Appeal judgment against Heathrow Airport expansion

The Airports National Policy Statement (ANPS) is the policy framework, created under the Planning Act 2008 by the Secretary of State for Transport to allow expansion at Heathrow Airport. It directs how any development consent application should be decided.

Section 10 of the Planning Act requires the Secretary of State to contribute to sustainable development with particular regard to mitigating climate change.

Friends of the Earth argued the Secretary of State failed to consider:

  • the Paris Agreement on climate change,
  • the non-CO2 warming impacts of aviation, and
  • the climate impacts of the operation of the airport beyond 2050.

Friends of the Earth argued that the ANPS and decision were unlawful on each count, because they each breached section 10 of the Planning Act 2008, and also the Strategic Environmental Assessment Directive (regarding the Paris Agreement only).

A strategic environmental assessment is a key tool in assessing environmental impact and achieving sustainable development. The purpose in law is to achieve a high level of environmental protection with a view to promoting sustainable development.

Legal action charity Plan B Earth ran a separate argument that the failure to consider the Paris Agreement breached section 5(8) of the Planning Act 2008.

The Court of Appeal agreed with both claimants on all climate arguments advanced. The ANPS remains of no legal effect unless reviewed – it is effectively a “zombie policy”.

The Supreme Court stage

A hearing at the Supreme Court between Friends of the Earth, Plan B and Heathrow Airport Ltd has now been set for 7-8 October 2020. The hearing will be livestreamed at  https://www.supremecourt.uk/live/court-01.html 

The Secretary of State did not seek permission to appeal and has now dropped out of the proceedings. So too has developer Arora Holdings. Heathrow Airport did receive permission to appeal the result at the Supreme Court, and this is the case that will be heard. Without the government in the picture, the appeal is now even more clearly about established commercial interests vs climate justice.

Summary of arguments

Heathrow Airport Ltd has sought to challenge all four of the climate grounds advanced by Friends of the Earth, and the one ground brought by Plan B.

The arguments centre on whether the government was legally required to consider the Paris Agreement, the warming impacts of non-CO2 emissions, and overall climate impacts for the full lifetime of the project beyond 2050 (the target date in the Climate Change Act).

Heathrow Airport is also saying that even if the government had acted unlawfully, the overall outcome would essentially be the same if the decision were taken again (i.e. the ANPS would still be designated). Consequently, the court should not prevent the ANPS having legal effect now in its current form (the remedy ordered by the Court of Appeal).

Heathrow Airport is inviting the Supreme Court to overturn the full result and is attacking both factual and evaluative judgments made by the Court of Appeal, based on what the Secretary of State said. However, that is a difficult task, as the Department for Transport is no longer involved to explain what it did and how it took the decision. Furthermore, the Secretary of State confirmed (at court) that it would not argue that the ANPS would be the same if it had taken into account the matters Friends of the Earth raised.

Essentially, Heathrow Airport’s case amounts to:

  • Paris Agreement: denying the agreement was part of government policy at the time the ANPS was designated, or that it is necessary to take it into account over and above the Climate Change Act when designating the ANPS under the Planning Act 2008, contrary to what the Court of Appeal found.
  • Non-CO2 warming impacts of aviation: similarly denying these impacts were required to be considered, because it was rational not to do so, because of uncertainty over their precise calculation, and that the “precautionary principle” did not apply.
  • Post-2050 climate impacts: that the Climate Change Act and its 2050 target were all that were required to be considered and that these emissions were already quantified.
  • Strategic Environmental Assessment: asserting that the Paris Agreement was not relevant and the Court of Appeal was wrong to find it was necessary to take it into account.
  • Rationality: asserting that the government had acted rationally in all these respects by discounting them, and it was wrong for the Court of Appeal to find it was irrational and so unlawful on this basis too when designating the ANPS

Potential outcome

There is no onward appeal from the Supreme Court.

If any one of the grounds that won in the Court of Appeal remains, and the Supreme Court agrees that the Order made should still stand, then the ANPS will remain of no legal effect until reviewed. The Secretary of State must then consider if they wish to leave that result undisturbed or review the ANPS policy framework.

If the Secretary of State reviews the framework, they will likely need to make changes that materially alter what the ANPS says. Such changes will need to be approved by Parliament following consultation, before the new ANPS can come into force. Even if the review were to be superficial, if Friends of the Earth’s Strategic Environmental Assessment ground remains intact, a new strategic environmental assessment and consultation on it would be required, because the previous one was unlawful for not considering the Paris Agreement.

If Heathrow Airport overturns the full result of the Court of Appeal, or persuades the Supreme Court that no remedy should have been given by the Court of Appeal despite finding the ANPS is unlawful, then the current ANPS will be reinstated. Heathrow Airport could then make an application for development consent, and the battle against expansion would move to the planning arena.


  1. Friends of the Earth were represented by David Wolfe QC (Matrix), Peter Lockley (11KBW), Andrew Parkinson (Landmark), and Leigh Day LLP.
  2. The London Boroughs (including the Mayor of London) and Greenpeace Ltd. They were all unsuccessful on appeal. Their case has now been dismissed.
  3. The Airports National Policy Statement is one NPS. Others cover energy, waste, water, and transport. A list is on the Planning Inspectorate’s website: https://infrastructure.planninginspectorate.gov.uk/legislation-and-advice/national-policy-statements/ ….






Heathrow to challenge third runway verdict using climate pledge

Airport to argue in supreme court it is bound to comply with UK carbon reduction targets

By Gwyn Topham Transport correspondent (The Guardian)   @GwynTopham
Tue 6 Oct 2020

Heathrow will argue in the supreme court this week that its proposed third runway would only ever be built in accordance with Britain’s climate commitments, as it seeks to overturn a court of appeal verdict that stopped the airport’s expansion plans.

A two-day hearing starts on Wednesday which could allow Heathrow to proceed once more with building an additional runway.

The expansion plans were approved in principle by parliament in 2018, under Theresa May’s government. Legal action by climate campaigners initially failed to force a judicial review. However, in a landmark judgment, the Court of Appeal ruled in favour of the case brought by the environmental litigation charity Plan B and Friends of the Earth.

Judges found that ministers had failed to take adequate account of Britain’s climate commitments under the 2015 Paris climate agreement when drawing up the aviation national policy statement (ANPS) which permitted Heathrow expansion.

The new government under Boris Johnson, a long-time opponent of the third runway, accepted the court ruling in February, leaving Heathrow to challenge it alone.

The airport will argue that the runway will be bound to comply with Britain’s carbon targets when it seeks to obtain planning permission, regardless of whether the then transport secretary, Chris Grayling, adequately took account of the 2015 Paris climate agreement.

The hearing will be conducted by video conference because of Covid-19 restrictions, and streamed live online. The verdict is not expected to be delivered until at least January.

Tim Crosland, the director of Plan B, said the government could “at least see a problem in admitting it’s not taking the Paris agreement seriously, given that maintaining the Paris temperature limit is vital to our collective future … Heathrow Airport Limited, however, has no such concerns.”

A Heathrow spokesperson said the airport fully expected to be held to account over climate obligations through the planning process, and that the ANPS made clear that approval for its runway “would be refused” if it had a material impact on the UK’s ability to meet its carbon reduction obligations.

”We’re appealing to the supreme court to allow this thorough planning process to proceed as it was designed.

“Given the timescales required to deliver complex infrastructure of this scale in the UK, it’s critical that we get on with laying the groundwork today for future operations that will be essential for a successful global Britain in the decade after Brexit,” they added.

The battle for expansion comes despite the pandemic leaving Heathrow with only a fraction of its normal air traffic and requiring just one runway to operate.

The Unite union is balloting for a strike over plans by Heathrow to impose pay cuts of up to 20% on long-serving workers, which the airport has defended as a means to preserve jobs.

John McDonnell, the Labour MP for the neighbouring Hayes and Harlington constituency, accused Heathrow of exploiting the pandemic to reduce wages, adding: “There is no excuse for the company imposing permanent wage cuts when we know that this crisis is temporary.”



The Aviation Environment Federation (AEF) said Heathrow’s argument that a third runway would comply with UK’s climate reduction targets was, however, always based on the assumption that emissions from international flights departing from the airport weren’t counted.

AEF said on 25.7.2019 that:

The reason why Heathrow says a third runway won’t impact the UK’s ability to achieve its carbon targets is because Heathrow doesn’t think those targets apply to aviation. So when John Holland Kaye signed up, as Heathrow CEO, to an alliance of business leaders pushing for net zero emissions he did so on the understanding that that target won’t apply for any international air traffic operating out of his airport. Airline emissions can carry on growing (while the airport invests in a bit of peatland restoration in Lancashire).

The only way that we can see for Heathrow to operate a third runway without increasing emissions is by closing one of its other two runways.