The Heathrow Airport Case Revisited


The last issue of the Energy Regulation Quarterly published an article[1] that featured the decision of the Court of Appeal of England and Wales in R (Friends of the Earth) v Secretary of State for Transport and others.[2] The decision offered a detailed examination of how climate change law can curtail large-scale infrastructure projects.

The Court in Heathrow held that the Secretary of State’s failure to take the United Kingdom’s commitments under the Paris Agreement[3] into account before approving the policy that would pave the way for the construction of a third runway at Heathrow Airport vitiated the approval. Specifically, the Court held that the Planning Act[4] required the Secretary of State to consider government policies on climate change, and that the Paris Agreement fell within the meaning of ‘government policy’.

Shortly after the article went to press the UK Supreme Court issued a unanimous decision allowing the appeal of the Heathrow decision.[5] The Editors felt a Case Comment on the latest decision would be of interest to the ERQ readers.


It is important to note that the appeal was brought not by the Secretary of State, but by the corporate owner of Heathrow Airport, which had already invested significant funds into the project when the Court of Appeal issued its decision.

The Court completely overturned the Court of Appeal’s decision in several key respects. Significantly, the Court held that the Paris Agreement did not enjoy the status of ‘government policy’ as that term is used in the Planning Act. The Court held that to read a liberal meaning of the term ‘government policy’ under the Planning Act would create a ‘bear trap’ for government. Instead, the Court favoured a narrower interpretation of ‘government policy’, which they circumscribed to carefully formulated written statements of policy that have been cleared by the relevant departments on a Government-wide basis. Specifically, the Court held as follows:

105…For the subsection to operate sensibly the phrase needs to be given a relatively narrow meaning so that the relevant policies can readily be identified. Otherwise, civil servants would have to trawl through Hansard and press statements to see if anything had been said by a minister which might be characterised as “policy”. Parliament cannot have intended to create a bear trap for ministers by requiring them to take into account any ministerial statement which could as a matter of ordinary language be described as a statement of policy relating to the relevant field.[6]

The Court further held that international treaties that have been ratified but not incorporated into domestic law are not binding domestically, and that ratification is an act that impacts only upon the international plane:

108…The fact that the United Kingdom had ratified the Paris Agreement is not of itself a statement of Government policy in the requisite sense. Ratification is an act on the international plane. It gives rise to obligations of the United Kingdom in international law which continue whether or not a particular government remains in office and which, as treaty obligations, “are not part of UK law and give rise to no legal rights or obligations in domestic law”…[7]

The Court was also very deferential to the Secretary of State’s weighing of various considerations pursuant to his authority under the Planning Act, and found it was reasonable:

155…It was not irrational to decide not to attempt to assess post-2050 emissions by reference to future policies which had yet to be formulated. It was rational for him to assume that future policies in relation to the post-2050 period, including new emissions targets, could be enforced by the [development consent order] process and mechanisms such as carbon pricing, improvements to aircraft design, operational efficiency improvements and limitation of demand growth.[8]

Clearly, the Heathrow Appeal was a resounding retreat back to a much more conservative and deferential approach, one which the decision below in the Heathrow Case had appeared (however briefly) to break free of.

While the churning sea that is the contest between international climate change commitments and domestic policy-making may have been momentarily quelled by the Supreme Court’s decision, these two warring decisions made by two unanimous higher level courts should demonstrate the ongoing tumult in the common law around this topic, and highlight the danger this ongoing legal uncertainty poses for proponents of large-scale infrastructure projects in the era of ‘net zero’ legislation.

*James MacDuff is a Partner at McInnes Cooper. He is a member of the firm’s Energy and Natural Resources Group and his practice focuses on corporate and regulatory law matters.

Melanie Gillis is a Lawyer at McInnes Cooper. She has a growing practice in commercial, construction, environmental and energy litigation.

  1. Melanie Gillis & James MacDuff, “When climate and construction collide: how net zero legislation might be used to challenge high-emitting infrastructure projects” (2020) 8:4 Energy Regulation Q 21.
  2. [2020] EWCA Civ 214.
  3. The Paris Agreement, 22 April 2016, Can TS 2016 No 9 (entered into force 4 November 2016) [Paris Agreement].
  4. Planning Act (UK), 2008, c 29, s 5(8).
  5. R (on the application of Friends of the Earth Ltd and others) v Heathrow Airport Ltd., [2020] UKSC 52.
  6. Ibid at para 105.
  7. Ibid at para 108.
  8. Ibid at para 155.

Leave a Reply