This morning activists gathered at the Supreme Court in Parliament Square as a two-day hearing began over the legality of a council planning decision.

A judgement in favour of the appellant, Sarah Finch from the Weald Action Group, could affect planned and future infrastructure projects and even prevent the controversial Cumbrian coalmine and the Rosebank oil and gas field.

The case centres around whether Surrey Council was right to ignore what are called ‘Scope 3’ emissions when it gave planning permission for the expansion of the Horse Hill oil well in Sussex. These include the future emissions of greenhouse gases from the burning of the fuel extracted over the next 20 years at the site. The correct interpretation and application of Environmental Impact Assessment Regulations (2017) is the crux of the issue, and whether the ’downstream’ emissions should be taken into account when considering the impact of potential projects.

As Sarah Finch puts it, you could say that cigarettes have no health effects unless you burn and inhale them – ignoring the effect of burning the oil extracted over the next two decades at Horse Hill is the same as claiming cigarettes are safe.

The judgement will likely take several months, but if the court decides that Surrey Council acted unlawfully, the repercussions are immense, because the same argument can be made against other much larger projects. Future Environmental Impact Assessments would be forced to include the ‘indirect effects’ of burning the extracted oil, gas or coal, which is what Surrey failed to do.

Friends of the Earth are supporting the case and their lawyer Katie de Kauwe explained that “Sarah’s legal challenge could ensure the full climate impacts of new fossil fuel developments have to be taken into account…We’re in a climate crisis and it’s absurd this is not happening already.”