Counting the Carbon: How a Surrey Oil Site Changed Climate Law

Few planning disputes become landmarks in climate litigation. R (Finch on behalf of the Weald Action Group) v Surrey County Council is one of them. On 20 June 2024, the UK Supreme Court held that Surrey County Council acted unlawfully when it approved an oil project without assessing the climate impact of burning the oil that project would produce.[1] The reasoning has since been applied to a coal mine in Cumbria and to oil and gas fields in the North Sea.[2]

Make no mistake: this was not a ban. It did something narrower and harder to avoid. It said that decision-makers must look at the full climate cost before they decide.[3]

The Story: Horse Hill

Horse Hill is an oil site near Horley, in Surrey. The project at the centre of the case involved six wells, around 20 years of production and an estimated 3.3 million tonnes of oil.[4] Oil extraction on that scale requires an environmental impact assessment (EIA), a formal study of a project’s likely effects.[5]

On climate, the developer’s assessment counted only emissions released within the well site: 140,958 tonnes of carbon dioxide (CO2) over the project’s life. It described the effect as “negligible”. The council accepted that approach, and its planning committee decided on 11 September 2019 that permission should be granted.[6]

The number left out was far bigger. The council’s own evidence estimated that burning the oil would release about 10.6 million tonnes of CO2, using a factor of 3.22 tonnes of CO2 per tonne of oil.[7] In the Court’s words, had those emissions been counted, the project’s figure would have been “nearly two orders of magnitude” greater than the on-site figure, and could not have been dismissed as negligible.[8]

Sarah Finch, who lives near the site, brought the challenge on behalf of the Weald Action Group.[9] She lost in the High Court. She lost again in the Court of Appeal, by a majority, on an alternative ground. The Supreme Court allowed her appeal.[10]

Why the Court Said the Emissions Count

The law requires an EIA to identify, describe and assess a project’s “direct and indirect significant effects” on the environment, including climate.[11] The Court of Appeal had treated the question of whether burning the oil counts as a matter of evaluative judgment, on which councils could reasonably give different answers. On this point, all five justices agreed that it is not.[12]

The majority, in a judgment by Lord Leggatt with Lord Kitchin and Lady Rose agreeing,[13] saw a question of causation. It was agreed that if the project went ahead, the oil would inevitably be refined and burned. On those facts, there was only one reasonable answer: the emissions are an effect of the project and must be assessed.[14]

The Court then took the reasons for leaving them out one at a time. Climate change does not depend on where emissions are released, so it did not matter that the oil would be burned elsewhere.[15] Refining does not break the causal chain. Oil, whose use is certain, is unlike steel, whose eventual uses are uncertain.[16] Government policy favouring domestic oil and gas goes to whether permission should be granted, not to what must be assessed.[17] And it is no answer that the information might not change the decision. EIA exists so that decisions are taken with full knowledge of the environmental consequences, and with the public aware.[18]

None of this turned on contested science. The Court cited the United Nations Environment Programme’s finding that close to 90% of global CO2 emissions stem from burning fossil fuels.[19]

The Dissent

Lord Sales, with Lord Richards, dissented. In his view, downstream emissions are a matter for national policy. It would be constitutionally inappropriate and disproportionate for a local planning authority to decide on them, and, read naturally, they are not effects “of the project”.[20] It remains the strongest argument against the majority.

What the Ruling Does Not Do

Finch decides what must be assessed, not what must be decided. EIA is a process. It does not prevent consent, but it ensures that decisions are made with the consequences in view.[21] The Court did not say when combustion emissions become “significant”, or what weight they carry when a council weighs a proposal. Nor did it settle “substitution”, the argument that oil left in the ground will simply be produced somewhere else. The majority noted UNEP modelling that each barrel left undeveloped leads to 0.2 to 0.6 barrels not consumed globally in the longer term, but it did not decide how such arguments should be weighed.[22]

The Ripple Effect

On 13 September 2024, the High Court quashed planning permission for the Whitehaven coal mine, applying Finch, after the Secretary of State conceded the claim.[23] In January 2025, Scotland’s Court of Session quashed the consents for the Rosebank oil field and the Jackdaw gas field because their assessments left out scope 3 emissions, the emissions from burning the fuel.[24] Work could continue, but production could not start without fresh assessments.[25] In June 2025, the government published non-statutory guidance on assessing these emissions for offshore projects.[26] On 21 October 2026, the government announced that Jackdaw could proceed. A decision on Rosebank was still awaited at the last report.[27]

Horse Hill itself is back before the council. Production there was reportedly suspended from 25 October 2024, and a retrospective planning application was submitted in May 2026.[28] Consultation ran to 13 July 2026, and Surrey County Council has reportedly suggested that no decision will come in 2026.[29] The developer says the climate effect is “not significant”.[30] That is a claim, and it is untested.

A Note for Students: Reading Finch

Start with the ratio decidendi: the reasoning necessary to reach the result, which binds later courts. Here, in simple terms, it is that where burning a project’s product is inevitable and can be estimated, those emissions are an effect of the project and must be assessed. Obiter dicta are remarks made in passing that were not necessary for the decision. They may persuade later judges, but they do not bind them. The Court’s references to UNEP’s substitution modelling are the kind of passage to read with that distinction in mind, because the majority did not decide how substitution should be treated.[31]

First, this was a judicial review, a challenge to how a decision was made rather than to whether it was the right decision. Second, a 3–2 split means the majority judgment states the law. The dissent does not bind anyone, but it shows where the next argument may come from. Lastly, the unanimous point: this was a question with one right answer, which a court decides itself, not an evaluative judgment, which a court will only disturb if no reasonable authority could have reached it.[32]

Why It Matters

Before Finch, the climate section of an oil project’s assessment could cover a small fraction of the project’s footprint. Now the largest number has to be on the table when the decision is made. For developers, consultants and lenders, scope 3 is a planning-risk question and not only a reporting one. Leaving it out has led to a decision being held unlawful at Horse Hill and to consents being quashed at Whitehaven, Rosebank and Jackdaw.[33]

Still, much remains open. How significant combustion emissions are, and what weight they carry, is for decision-makers, and the new Horse Hill application will test it. The boundary between oil and products like steel is untested. And the planned replacement of EIA with environmental outcomes reports may change the framework in which Finch operates.[34]

Finch did not tell anyone what to decide. It told them what they must look at first. In climate law, that is the difference between a decision that can be scrutinised and one that cannot.

Disclaimer: This article is general commentary and is not legal advice. It reflects the law and public information as at 1 November 2026, some of which, including the Horse Hill, Jackdaw and Rosebank matters, is still developing.

Citations

1. R (Finch on behalf of the Weald Action Group) v Surrey County Council and others [2024] UKSC 20 (‘Finch’), [174]. Judgment of 20 June 2024: https://www.supremecourt.uk/uploads/uksc_2022_0064_judgment_c3d44bb244.pdf

2. Friends of the Earth v Secretary of State for Levelling Up, Housing and Communities; South Lakeland Action on Climate Change v Secretary of State for Levelling Up, Housing and Communities [2024] EWHC 2349 (Admin); Landmark Chambers, ‘High Court Quashes Whitehaven Coal Mine Permission’ (13 September 2024): https://www.landmarkchambers.co.uk/news-and-cases/cases/high-court-quashes-whitehaven-coal-mine-permission ; Cornerstone Barristers, ‘Permission for New North Sea Oilfields Quashed in Another Interesting Analysis of Remedy’ (January 2025): https://cornerstonebarristers.com/permission-for-new-north-sea-oilfields-quashed-in-another-interesting-analysis-of-remedy/

3. Finch (n 1) [3], [62], [174].

4. Finch (n 1) [31]; UK Supreme Court, ‘Press Summary: R (Finch) v Surrey County Council [2024] UKSC 20’ (20 June 2024): https://supremecourt.uk/uploads/uksc_2022_0064_press_summary_0af73e4878.pdf

5. Finch (n 1) [29], [53].

6. Finch (n 1) [38], [82].

7. Finch (n 1) [81]. The figure is the estimate in the council’s evidence.

8. Finch (n 1) [82].

9. Finch (n 1) [44].

10. Finch (n 1) [45]–[46], [174]; R (Finch) v Surrey County Council [2020] EWHC 3566 (Admin); R (Finch) v Surrey County Council [2022] EWCA Civ 187.

11. Town and Country Planning (Environmental Impact Assessment) Regulations 2017 (SI 2017/571), reg 4(2); Directive 2011/92/EU (as amended by Directive 2014/52/EU), art 3(1); Finch (n 1) [53].

12. Finch (n 1) [59]–[60], [321]–[325].

13. Finch (n 1) [175]; Press Summary (n 4).

14. Finch (n 1) [45], [79]–[81].

15. Finch (n 1) [97], [101]–[103].

16. Finch (n 1) [112]–[139].

17. Finch (n 1) [140]–[151].

18. Finch (n 1) [152]–[154], citing Berkeley v Secretary of State for the Environment [2001] 2 AC 603 (HL).

19. Finch (n 1) [1], citing UNEP, Production Gap Report 2023.

20. Finch (n 1) [252]–[260], [276], [327].

21. Finch (n 1) [3], [62].

22. Finch (n 1) [2], citing UNEP, Production Gap Report 2019, p 50.

23. Landmark Chambers and Friends of the Earth (n 2).

24. Greenpeace Ltd and Uplift v Secretary of State and North Sea Transition Authority (Court of Session, Outer House, January 2025); Cornerstone Barristers (n 2).

25. Institute for Government, ‘Jackdaw and Rosebank’ (explainer, last updated 22 October 2026): https://www.instituteforgovernment.org.uk/explainer/jackdaw-and-rosebank

26. Department for Energy Security and Net Zero, ‘Environmental Impact Assessment (EIA) – Supplementary guidance for assessing the effects of downstream scope 3 emissions on climate from offshore oil and gas projects’ (June 2025): https://assets.publishing.service.gov.uk/media/6853fa3d1203c00468ba2b15/Supplementary_guidance_-_Effects_of_Scope_3_Emissions.pdf

27. Institute for Government (n 25).

28. ‘UK: UK Oil & Gas submits a retrospective planning application for its Horse Hill oil field’, Energy-pedia (5 May 2026): https://www.energy-pedia.com/news/united-kingdom/uk-oil-gas-submits-a-retrospective-planning-application-for-its-horse-hill-oil-field-203798 This reproduces a company announcement.

29. ‘energy B deal on Horse Hill’, Drill or Drop (20 October 2026): https://drillordrop.com/2026/10/20/energy-b-deal-on-horse-hill/ ; ‘Horse Hill’s predicted 2m tonnes of carbon emissions “not significant” for climate – UKOG’, Drill or Drop (17 June 2026): https://drillordrop.com/2026/06/17/horse-hills-predicted-2m-tonnes-of-carbon-emissions-not-significant-for-climate-ukog/

30. Drill or Drop, 17 June 2026 (n 29). This is the developer’s position as reported.

31. Finch (n 1) [2].

32. Finch (n 1) [59]–[60], [321]–[325].

33. Finch (n 1) [174]; Landmark Chambers and Cornerstone Barristers (n 2); Institute for Government (n 25).

34. Levelling-up and Regeneration Act 2023, pt 6. The status of the replacement regime has not been verified for this article.