Court of Appeal clarifies emissions assessment

In May 2025, the Court of Appeal of England and Wales made a substantial ruling in the case of Andrew Boswell, R (on the application of) v The Secretary of State for Energy Security and Net Zero & Anor. This influential case centred on the planning decision related to a contentious gas-fired electricity generating station at Teesside that included carbon capture and storage (CCS) technology. The crux of the judgement centred on whether the Secretary of State for Energy Security and Net Zero had made legal mistakes in evaluating the greenhouse gas (GHG) emissions anticipated from this development.

Andrew Boswell appealed against the planning approval given to Net Zero Teesside Power Ltd and Net Zero North Sea Storage Ltd, arguing that the Secretary of State did not sufficiently assess the environmental consequences of the projected GHG emissions. Initially, the High Court dismissed Boswell’s claims, supporting the view that the Secretary of State’s decisions were consistent with the Planning Act 2008. The Court of Appeal, while considering the appeal, paid close attention to several critical factors including the application of IEMA guidance on GHG emissions assessment, the interpretation of National Policy Statements (NPSs), and the legal frameworks steering infrastructure projects.

Throughout the appeal process, three main grounds were scrutinised. These involved whether the Secretary of State had erred in relying on specific guidance for GHG emissions assessment, whether the legal standards articulated in National Policy Statement EN-1 appropriately covered significance assessments, and if reasonable conclusions had been made regarding the project's environmental impact. The judges – Sir Keith Lindblom, Lord Justice Stuart-Smith, and Lord Justice Holgate – highlighted their essential role in evaluating the legality of the Secretary of State's decision-making process instead of weighing the merits of policy or the necessity for the energy project. They firmly stated that environmental impact assessments must ensure lawfulness rather than influence policy direction, which is the responsibility of the executive arm of the government.

In their analysis, the Court of Appeal unequivocally recognised that emissions linked to the development were significant enough to raise concerns. However, they supported the Secretary of State’s findings that these emissions could be contextualised within the wider scope of the UK's climate commitments. They concluded that while the project would generate considerable adverse emissions, it remained pivotal in the government's strategy to meet national net zero targets by 2050.

The judges further stressed that planning consent decisions should factor in broader national interests, including an urgent demand for enhanced energy infrastructure to foster a low-carbon economy. Hence, despite acknowledging the significant environmental impacts from GHG emissions, the decision adhered to a legal framework that allowed these impacts to be evaluated alongside the critical need for energy stability.

Overall, the Court of Appeal’s ruling sets a significant precedent for future energy project planning decisions in the UK. It underscores the necessity of framing environmental impacts within national policy contexts while ensuring that planning authorities maintain legal accountability in their decision-making. This judgement reconfirms the delicate balance that must be struck when considering the environmental ramifications of energy infrastructure projects against the pressing demands of national energy security and climate commitments