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| 6 minutes read

High Court stresses climate change urgency, but suggests narrow road for judicial review

On 31 January 2023, the High Court dismissed an application for judicial review from the Bristol Airport Action Network Co-ordinating Committee (“BAAN”) challenging Bristol Airport’s proposed expansion. The decision comes in the wake of the Court of Appeal’s recent decision in Friends of the Earth v Secretary of State for International Trade/UK Export Finance [2023] EWCA Civ 14 (“UK Export Finance”, discussed here), where the Court emphasised the margin of appreciation afforded to government. Viewed together, the cases suggest that the path to challenging decisions on climate change grounds may be a narrow one, with deference shown to public bodies’ assessments and emphasis on the particular facts of each case. Further challenges should nonetheless be expected, and the Court went out of its way to emphasise the “very great importance” of climate change. It also provided interesting guidance on how public bodies address non-CO2 emissions.  


Bristol Airport Ltd (“Bristol Airport”) applied for planning permissions that would enable it to increase its capacity by 20% to approximately 2 million passengers per year. North Somerset Council ("NSC”) rejected the application on environmental grounds. Following a lengthy inquiry, a panel of three planning inspectors allowed Bristol Airport’s appeal on the basis that:

The relevant development policies did not directly address aviation emissions and there was uncertainty as to how to assess and deal with non-CO2 emissions.

Given scientific uncertainty and Bristol Airport’s intention to consider non-CO2 emissions in its Carbon and Climate Change Action Plan, it would be unreasonable to give weight to it against Bristol Airport’s proposal.

It was not necessary to consider the local authority’s carbon budget when determining the proposal’s climate change impact. Aviation emissions resulting from the proposal were not so significant that they would have a material impact on the government’s ability to meet its climate change target and carbon budgets.

On 9 May 2022, BAAN was granted permission to apply for planning statutory review.

High Court

The claimants broadly argued that the expansion would have a serious and unacceptable effect on climate change. Mr Justice Lane dismissed BAAN’s application on all six of the following grounds (see Bristol Airport Action Network Co-Ordinating Committee (acting through Stephen Clarke) v Secretary of State for Levelling Up, Housing and Communities).

Grounds 1 and 2 – Policy interpretation

BAAN argued that the panel had erred in law in its interpretation of two local development plan policies (“CS1” and “CS23”) and a UK Government airport runway policy published in 2018 (the “MBU”).

Development plan policies

The Court reaffirmed the panel’s finding that CS1 and CS23 did not directly address aviation emissions. The Court acknowledged that both policies were broadly worded, but noted that neither made specific reference to aviation emissions (in contrast to the policies’ approach to other matters). The Court also noted that “aviation emissions… can occur at any point in an aircraft’s journey” and were “of a different character” to carbon emissions which were within the ambit of the local authority.  The panel had properly engaged with the “indirect” effect of the emissions, which meant they were permitted to consider that these emissions were “not so significant that they would have a material impact on the government’s ability to meet its climate change target and budgets”.


The Court held that the panel was correct in finding that aviation emissions should be considered at the national level, and that it had properly engaged with the environmental and climate impacts of the proposed project. The Court found that, even if the panel was incorrect in its interpretation that any admitted increase in CO2 emissions was not a matter for local decision-makers, there was nothing to suggest that the increase in aviation emissions was treated as insignificant for that reason. 

Ground 3 – Presumption of statutory duty

BAAN also argued that the panel erred in law in treating the Climate Change Act 2008 (“CCA”) and the various duties placed upon the Secretary of State (“SoS”) under it as a “separate pollution regime”, and in assuming that there was an irrebuttable assumption in paragraph 188 of the National Planning Policy Framework ("NPPF") that this regime would operate effectively. Lane J found that the panel’s reasoning did not depend on paragraph 188 of the NPPF, and in any event, that there was no basis for contending that the panel had assumed that this assumption was irrebuttable.

Ground 4 – Impact on local carbon budget

BAAN argued that the panel erred in law by refusing to consider the impact on the local authority’s carbon budget. Lane J found that the impact of the proposal on the budget was only a consideration “to which the decision-maker may have regard if, in their judgment and discretion, they think it is right to do”, and that the panel was entitled to exercise its discretion in deciding to give it no weight. The panel had not acted irrationally in doing so. 

Ground 5 – Incorporation of non-CO2 emissions in the environmental impact assessment

BAAN submitted that the panel had erred in finding that Bristol Airport’s environmental impact assessment (“EIA”) was lawful on the basis that the EIA did not address the impact of non-CO2 emissions. Lane J found that the panel lawfully excluded consideration of non-CO2 emissions from that assessment. The lack of scientific consensus in relation to proper calculation of these emissions was a legitimate reason for the panel to decide not to conduct the calculations, and the EIA dealt with the point by concluding that such quantification was currently not possible.

Ground 6 – Replacement habitat for bats

The panel accepted a replacement habitat proposal as part of the proposed expansion plans, which were intended to comply with Special Area of Conservation objectives. BAAN argued that the provision of replacement land for horseshoe bats should have been treated as “compensation” rather than “mitigation”, which would require a negative assessment of the proposal and consideration of whether there was an absence of alternative solutions. The Court rejected this assertion, noting that the panel had reached its decision by reference to uncontested evidence that the replacement land would be provided in advance so as to avoid any impact on the SAC.   


The aviation sector will welcome this decision, as there are several other airport expansions under consideration. The case may also suggest an emerging trend in judicial thinking that emphasises the limited scope of judicial review and the narrow circumstances in which courts will intervene in decision-making to ensure adherence to climate change obligations, although the fact-specific nature of these decisions has been emphasised repeatedly.

Both this case and the UK Export Finance case include obiter comments recognising the importance of climate change and the role of the courts in this regard. In this case, Lane J opened his judgment by commenting: “Climate change, with its consequences for human and other life on this planet, is generally regarded as a matter of very great importance. In the same month in which this appeal was heard in Bristol, world leaders and other policy makers gathered …for COP27… There is an international consensus on the need to achieve substantial reductions in CO2 emissions. The Intergovernmental Panel on Climate Change 2021 was widely reported as being a “Code Red for Humanity”, such is the present level of concern.” The judgment is bookended by a final comment reiterating the importance of climate change, but emphasising that: “the main issue in this case is not whether emissions from any additional aircraft using Bristol Airport should be ignored. Plainly, they should not. Rather, it is about how and by whom those emissions should be addressed.” Similarly, in UK Export Finance, the Court of Appeal recognised that climate change represents “an urgent and potentially irreversible threat to human societies and the planet” but that the Court’s “task is only to establish whether the [government’s] decision is vitiated by an error of law”.

It remains to be seen how these comments will impact on the strategy of claimants more broadly. For the moment, following the successful 2022 Net Zero Strategy judicial review, claimants seem to remain eager to commence litigation to achieve climate change goals. At least two recent judicial reviews have been filed in the UK, brought in relation to the Cumbria Coal Mine and the North Sea Transition Authority’s approval of oil and gas licensing.. Appeals of the Bristol Airport and UK Export Finance decisions also appear likely. On 20 February, Friends of the Earth lodged an application for permission to appeal to the Supreme Court; BAAN has also indicated that it intends to appeal Lane J’s decision (see press coverage).

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