Cumulative impacts and carbon budgets

On 7 July 2023, Mrs Justice Thornton DBE handed down judgment in R (Boswell) v Secretary of State for Transport [2023] EWHC 1710 (Admin).

The case concerned three decisions of the Secretary of State for Transport to grant consent for three road schemes in Norfolk. In making his decision, the Secretary of State assessed the carbon emissions expected to be generated by each scheme and concluded that, when compared with the UK’s carbon budgets which span the period from 2023 to 2037, the increase in emissions from each of the three schemes (separately) is not significant (0.001%-0.004% of any carbon budget).

The claimant argued that the Secretary of State was under a duty to assess the cumulative environmental effects with other existing and/or approved projects. He argued that when considered together, the three schemes in combination with other developments in the local area amount to 0.47% of the UK’s 6th Carbon Budget. And that that percentage, for a relatively small scheme in Norfolk, is disproportionate given other demands on the economy.

The primary legal argument concerned the Infrastructure Planning (Environmental Impact Assessment) Regulations 2017 (“IEIA”). The Claimant argued it was a legal requirement to assess the significance of the cumulative impacts of a proposed project with existing and/or approved projects (Schedule 4, paras 4 and 5 IEIA). Projects should not be split up to avoid considering their true environmental effects. The Secretary of State submitted that the assessment of cumulative impacts was a question of judgment for the decision maker, not law. The Judge agreed with the Secretary of State.

Mrs Justice Thornton DBE concluded that there was no breach of the regulations because:

  • the question of what impacts should be addressed cumulatively and whether they are significant are matters of judgment for the Secretary of State, and its view should be afforded considerable weight;
  • the carbon emissions from each scheme were considered against the carbon budgets;
  • there was some consideration of cumulative impacts of the three road schemes – the fact that this cumulative figure was not assessed against the carbon budgets is a matter of judgment for the Secretary of State;
  • carbon emissions are not limited to a geographical boundary and so there is a logical coherence to the Secretary of State’s decision not to compare the combined local road scheme emissions against a national carbon target.

Mrs Justice Thornton DBE did however state that “EIA for any proposed project must therefore give proportionate consideration to whether and how that project will contribute to or jeopardise the achievement of these [carbon budget] targets” (§71)- absence of any relevant assessment therefore may be subject to challenge.

Concerning EIA and climate change, all eyes are now on the outcome of Supreme Court case of Finch. That case concerns the failure in the environmental impact assessment to consider the downstream greenhouse gas emissions that would inevitably occur when the oil extracted from the site was later refined and used.