Cleared for take-off? What the London Luton Airport ruling means for major infrastructure projects

The High Court has dismissed a legal challenge to Luton Rising’s planned expansion of London Luton Airport brought by local campaign group Luton and District Association for the Control of Aircraft Noise (LADACAN). The judgment provides welcome clarity on some key issues for infrastructure scheme promoters, including on the approach to assessing the effects of greenhouse gas emissions. Tom Henderson, who leads TLT’s legal team advising Luton Rising, and team member Will Massa, provide a summary of the ruling.

R(LADACAN) v SST and Anor [2025] EWHC 3206 (Admin).

Background

In 2023, promoter Luton Rising submitted an application for development consent, seeking authorisation for a substantial redevelopment of London Luton Airport in order to increase capacity from 19 million to 32 million passengers per year. The Secretary of State for Transport (SoSfT) granted consent in April 2025. In August 2025, LADACAN received permission to bring judicial review proceedings in respect of the decision, citing six grounds. On 8 December 2025, Mrs Justice Lang dismissed five of the grounds in a wide-ranging judgment with the sixth stayed pending the outcome of a separate challenge to the Government’s Jet Zero Strategy.

The Claimant's Grounds

Inbound flight emissions (Grounds 1 and 2)

LADACAN argued that to exclude the impact of greenhouse gas emissions from inbound flights in the environmental impact assessment (EIA) was an error of law following R (Finch) v Surrey County Council [2024], the landmark case in which the UK Supreme Court found that planning permission was unlawful because the EIA had not assessed downstream (Scope 3) emissions. The Court disagreed. Whilst the emissions from inbound flights for the Luton scheme had been quantified and published, the Court accepted the SoSfT’s view that the significance of the effects of such emissions were not capable of meaningful assessment. This is because the relevant benchmarks, including the Government’s Sixth Carbon Budget and Jet Zero Strategy, calculate emissions for outbound flights only, an approach consistent with standard national and international practice to avoid the double counting of emissions between countries. Importantly, the Court found that Lord Leggatt’s analysis in the Finch judgment was not confined to the question of the sufficiency of evidence for establishing the causation of effects – where an effect was identified but was not meaningfully capable of being ascribed significance, that was a legitimate conclusion, compliant with the EIA process.

LADACAN also claimed that the SoSfT had acted irrationally in failing to take account of a material consideration, namely the Examining Authority’s treatment of inbound flight emissions in relation to the Gatwick Airport Northern Runway Project. Again, the Court disagreed, finding that this submission was wrong “both in principle and on the facts” - the Examining Authority’s views on Gatwick were recommendations, not a decision; they related to a different project at a different airport; and they had been rejected by the SoSfT.

Non-CO2 emissions (Ground 3)

The claimant challenged the decision, post-Finch, not to quantify non-CO2 emissions produced from aviation which have a warming effect (e.g. water vapour and nitrogen oxides). This was also rejected. The Court found that these effects had not been ignored in the EIA, rather they had been assessed qualitatively rather than quantitatively because of significant scientific uncertainty about the scale of effects produced, and the lack of any relevant benchmark to contextualise their impact. The Court confirmed that there was no legal obligation to attempt to quantify such emissions and that the nature and extent of assessment remains a matter of judgment for the decision-maker.

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Climate Change Act 2008 as a 'pollution control regime' (Ground 4)

LADACAN claimed that the SoSfT had erred in law by relying on the Climate Change Act 2008 as a separate form of 'pollution control regime' when assessing the project's climate impacts. The Court rejected this submission, drawing on Lane J’s analysis of a similar submission in the 2023 Bristol Airport expansion judicial review - (Bristol Airport Action Network Co-ordinating Committee) v Secretary of State for Levelling Up, Housing and Communities [2023] PTSR 85.]. Distinguishing Gladman Developments Limited v Secretary of State for Communities and Local Government [2020] PTSR 128, which was concerned with air quality issues which have a “a significant and discrete local element”, Lane J noted that the Climate Change Act 2008 sets carbon budgets and emissions trading schemes, providing specific national-level controls designed to manage emissions. The Court held that neither Finch nor the revised wording in the National Planning Policy Framework in relation to climate change mitigation and adaptation (December 2024) had altered the position following the judgment in Bristol Airport. The Court further emphasised that it is well established in case law that decision-makers are entitled to have regard to regulatory regimes outside the planning system and should generally assume these will operate effectively (most recently considered in R (APT) v Secretary of State for Transport [2025]).

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Compliance with Section 85 of the Countryside and Rights of Way Act 2000 ("CROWA") (Ground 5)

Section 85(A1) CROWA imposes an enhanced duty on relevant authorities to “seek to further the purpose of conserving and enhancing the natural beauty” of areas outstanding natural beauty. We have previously discussed this duty in our Infrastructure Planning Blog. In this case, the Chilterns National Landscape, situated roughly 5km west of the airport, was the area under consideration. Luton Rising and the Chilterns Conservation Board had been unable to agree on an appropriate amount of compensation to mitigate the aesthetic impacts caused by development. Having considered representations from both parties, and from Natural England, the SoSfT concluded that Luton Rising’s proposal of £250,000 was a “reasonable and proportionate contribution” and sufficient to meet the s85 duty in this instance. LADACAN submitted that the SoSfT had failed to give adequate reasons for that conclusion (and therefore questioned whether she had in fact performed the s85 duty). This claim was dismissed by the Court who noted that the SoSfT had considered the issues in detail, grappled sufficiently with the views of the relevant parties (which she was not obliged to accept),and set out her reasoning and conclusions.

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What are the main takeaways?

The judgment provides some useful clarifications on the evaluative scope permitted under the EIA regime, namely:

Further justification that it is legitimate to assess the significance of environmental effects against an appropriate benchmark (e.g. a national carbon budget) and that where the significance of a quantified effect is not capable of meaningful assessment, due to the methodology applied in appropriate benchmark, it is legitimate to conclude as such for the purposes of EIA.
Confirmation that where there is a prevailing lack of scientific certainty or lack of a relevant benchmark as to the significance of effects of non-CO2 emissions, it is legitimate to deviate from the requirement in the EIA regulations to use established methodologies of quantification. Qualitative or high-level assessment will suffice.
When assessing environmental impacts, the principle that decision-makers are entitled to have regard to separate regimes of environmental outside of the planning system control (e.g. the Climate Change Act 2008 regime), and to assume that such regimes will operate properly, remains undisturbed.

Looking ahead

This is the first case to consider how Finch applies to airport schemes, where the interaction between project-level emissions and national climate policy is complex. The judgment suggests that, provided decision-makers engage properly with the evidence and explain their reasoning, there is a reasonable margin of discretion in how they assess Scope 3 greenhouse gas emissions. We are likely to see further challenges in this area as the Government progresses other major infrastructure projects, not least the proposed third runway at Heathrow Airport. The stayed sixth ground of challenge in the Luton case (relating to the lawfulness of the Jet Zero Strategy itself) may also have implications for how aviation emissions are assessed in future cases.

If you're involved in a major infrastructure project and are considering how to approach the assessment of greenhouse gas emissions, now is the time to:

Review your EIA methodology to make sure you can demonstrate why your chosen benchmarks are appropriate.
Consider whether you should assess certain categories of emissions qualitatively rather than quantitatively, and document your reasoning.
Think about how national climate policy frameworks interact with your project-level assessments.

Our market-leading Infrastructure Planning and Parliamentary team is here to help you navigate these complex issues. Please get in touch to discuss how this judgment might affect your project.

Authors: Tom Henderson and Will Massa

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Date published

12 Dec 2025