The decision came as part of a three-part ruling in a case brought by Friends of the Earth and other campaign groups against the construction of the new runway at the west London site in R (Friends of the Earth) v Secretary Of State For Transport and Ors.

The plan for Heathrow’s expansion was given the go-ahead in October 2018, but has now been temporarily derailed as the government’s Airports National Policy Statement (ANPS) did not provide non-financial disclosures on the environmental risks, or detail on CO2 emissions either initially or post 2050.  

This is despite the fact the government signed up to the Paris Agreement on climate change and the United Nations’ Sustainability Development Goals (SDG) in 2015. The 17 SDG goals set a framework for climate change and sustainability reporting and should be taken into account when planning infrastructure projects.

While the Department of Transport won its arguments on noise levels, pollution and local habitat degradation, the Court ruled that it was unacceptable to produce an ANPS costing ignoring climate change and related disclosures.

The Court ruling centred around the legislative provisions concerning the government’s policy and commitments on climate change, in particular the provision in section 5(8) of the Planning Act, which requires that the reasons for the policy set out in the ANPS ‘must … include an explanation of how the policy set out in the statement takes account of government policy relating to the mitigation of, and adaptation to, climate change’.

In the ruling, the judges stated: ‘We have concluded, in particular, that the designation of the ANPS was unlawful by reason of a failure to take into account the government’s commitment to the provisions of the Paris Agreement on climate change, concluded in December 2015 and ratified by the United Kingdom in November 2016.’

Under UK law, the Paris Agreement ought to have been taken into account by the Secretary of State in the preparation of the ANPS and an explanation given as to how it was taken into account, but it was not.

In order to progress the project, the government has been told it will have to redraft the relevant sections of the ANPS to reflect climate change impacts, disclosures and cost benefit analysis. This is clearly stated as a requirement in section 6(5) of the Planning Act.

The timing and scope of any review is in the government’s hands as the Court did not set any deadlines for revision of the proposal.

The Court was keen to stress that the ruling was not affected by political considerations, as the airport expansion has been a controversial project from the outset, with a number of Conservative MPs resigning over the issue.

The ruling stated: ‘We have made it clear that we are not concerned in these proceedings with the political debate and controversy to which the prospect of a third runway being constructed at Heathrow has given rise. That is none of the court’s business. We have emphasised that the basic question before us in these claims is an entirely legal question.’

According to court papers, the government has not sought permission to appeal the decision at the Supreme Court.

In a statement, Grant Shapps, secretary of state for transport, said: ‘We have always been clear that Heathrow expansion is a private sector project which must meet strict criteria on air quality, noise and climate change, as well as being privately financed, affordable, and delivered in the best interest of consumers. The government has taken the decision not to appeal this judgment. The promoters of the scheme will be able to seek permission from the Supreme Court to appeal if they wish.

‘As part of its judgment, the court has declared that the Airports National Policy Statement is of no legal effect unless and until the government carries out a review under the Planning Act 2008.

‘The court’s judgment is complex and requires careful consideration. We will set out our next steps in due course.’

Head of legal at Friends of the Earth, Will Rundle, said: ‘The fact that the court has ruled government broke the law by not considering the Paris Agreement, nor the full climate impacts of a third runway, is a huge step forward in ensuring they take their own climate commitments more seriously – for all our sakes.

'It’s also a massive climate justice win for present and future generations.’

A recent report by the Financial Reporting Council (FRC) said that organisations should adopt the Task Force on Climate-related Financial Disclosures (TCFD) framework to report on climate-related issues, rather than using ad hoc reporting approaches.

Despite the lack of climate change impact figures in the Heathrow expansion document, the government expects all listed companies and large asset owners to disclose in line with the TCFD recommendations from 2022. 

By Sara White

Essential reading: Reporting: UN sustainable development goals (SDGs) explained