For anyone involved in environmental and planning law, getting a major project to consent can sometimes feel like a journey through Dante’s Inferno, one circle after another.

It is exactly that imagery that Humphreys J reached for in a recent Irish High Court decision: if we’re heading for the “ninth circle of climate hell”, the route out isn’t a single leap to paradise, but a phased journey back through the outer circles.

In Friends of the Irish Environment CLG v An Coimisiún Pleanála [2026] IEHC 205, he used the metaphor to make a simple point: a project’s emissions should not be assessed in isolation, but in the context of a wider journey towards legally binding targets. On the facts, the Court accepted that displacing less efficient fossil fuel generation with more efficient gas-fired generation could, in principle, move us back up through the circles rather than deeper into them.

Not Just Fossil Fuels

While this case is about fossil fuel development, the reasoning has broader application: the same “baseline/counterfactual” logic could apply to a number of categories of projects for example waste projects (e.g. where a facility displaces landfill methane or exports), transport schemes (e.g. where a project shifts trips from private car to public transport), and even heat/industrial upgrades (e.g. electrification or energy efficiency measures displace higher‑carbon on-site fuel use).

Northern Ireland angle: s.52, carbon budgets, and what might come next

From a Northern Ireland (NI) perspective, the judgment is also a useful comparator because of the parallels (and differences) between s.15 of the Climate Action and Low Carbon Development Act 2015 (as amended) and s.52 of the Climate Change Act (Northern Ireland) 2022.

One practical difference is scope: NI’s s.52 duty is framed as an obligation on government departments when exercising their functions, whereas the Irish regime has a much broader application across public decision-making, so we can expect more frequent judicial consideration in ROI.

Humphreys J held that s.15 does not expressly refer to carbon budgets or sectoral emissions ceilings and therefore decision-makers are not required to convert national carbon budgets into project-level caps for individual permissions. Indeed, he cautions against such an approach: “such an approach would potentially stifle all development”.

In NI, however, s.52 expressly includes an obligation on departments to exercise their functions (in so far as is possible to do so) in a manner that is consistent with the obligation in s.24 to ensure that the net Northern Ireland emissions account for each budgetary period does not exceed the carbon budget for that period.

That extra “hook” is likely to matter when (not if) we see a future challenge arguing that a departmental decision-maker has failed to demonstrate how a major project can sit within budgeted pathways. It will be interesting to see how our courts treat that distinction in due course.  Given some of the practical difficulties in quantifying baseline, projecting future carbon emissions and even technical disputes in respect of carbon emission calculations, it is likely we will see some judicial consideration of the extent to which departments can rely upon the qualifier of “in so far as is possible to do so”.

Key takeaways for developers and planning professionals

Baseline, baseline, baseline

In Friends of the Irish Environment, the Court accepted that, in the context of the all-island energy market, grid stability means some mix of sources will be needed while renewables scale and that a project which displaces more carbon‑intensive generation can be a relevant part of the assessment.

Where a developer wishes to rely on an argument that their project will reduce existing emissions, marking a step upwards and outwards of the “climate inferno”, they first need to set out how existing demand is currently met and the associated carbon footprint. This will vary from project to project.

Carbon context

The key comparison is not a project’s gross emissions, but the project vs counterfactual (i.e. what happens if the project is refused – what fills the gap?, or what is displaced or replaced if the project is consented?). That framing can be outcome-determinative in how climate impacts are evaluated.

A developer will need to set out how their project will actually displace or replace a more carbon intensive alternative.  Depending on the development project this might require a careful analysis of how such displacement can be secured or guaranteed. The English High Court decision in respect of the Cumbria Coal Mine provides a likely indication of the evidential burden that will be faced by developers (see here for analysis of that decision).

Future demand

The judgment sounds a note of caution in assuming that demand for energy is constant:

“But demand is not constant – it has been on an ever-increasing upward trend, with occasional and purely temporary fluctuations, since the start of the industrial revolution.”

Therefore, consideration needs to be given to projected future demand and the impact that might have on overall carbon context.

Environmental Statement and decision wording (including conditions)

If the development can credibly be shown to replace or displace more carbon intensive activity, that needs to be evidenced clearly and cogently in the application documents and considered and recorded in the recommendation or decision document.

Where appropriate, it should also translate into conditions that are expressly framed by reference to the pathway to the 2050 climate target: in this case, the permission included a ten-year construction window and a condition limiting operational use to 31 December 2050. It specifies that the plant may be used only as backup to intermittent renewable energy, unless fresh permission is obtained to permit use for other purposes. This was a key factor in upholding the decision of the Board and reflects the highly regulated nature of the All-Island electricity market. This might be more difficult in other types of development projects.

Procedure matters: evidence, timing, and the limits of JR

Judicial review is not a do-over

Another strong theme in the judgment is that judicial review is not generally a “second chance to dream up new issues”.

If technical criticisms (modelling inputs, methodology, assumptions) could have been raised during the planning process, the Court was slow to entertain them for the first time in litigation.

Objectors should ensure that they present any technical evidence, particularly that which disputes a developer’s methodology before the decision maker.

Burden of proof and the need for expert evidence

The judgment also contains several important remarks in respect of the burden of proof and the need for expert evidence to support arguments. That message resonates strongly in Northern Ireland, a theme reflected in McAlinden J’s recent addendum judgment in the A5 litigation, Hassard and Others [2026] NIKB 10.

The practical takeaway is simple: get the right professional and technical advice early and put your best evidence before the decision-maker before the decision is made.

Conclusion

Humphreys J’s Dante analogy is an indication that courts of ROI are adopting a more nuanced view of how climate commitments are achieved. We are not expected to vault from the ninth circle straight into decarbonised utopia; progress will often be made through incremental steps. But those steps will only withstand scrutiny if they are supported by robust, context-specific evidence on the baseline, the counterfactual and what is genuinely being displaced. While the ruling is not binding in Northern Ireland it may provide a useful indicator of how Northern Ireland’s own climate obligations will be interpreted in the future.

For legal guidance and advice on how this judgement may apply to your business, please contact Maria O’Loan or another member of our Planning and Environment team.

While great care has been taken in the preparation of the content of this article, it does not purport to be a comprehensive statement of the relevant law and full professional advice should be taken before any action is taken in reliance on any item covered.