The Airports National Policy Statement is ruled illegal as a result of government failure to take account of its Paris Agreement commitments.

In R (Plan B Earth and Others) v. Secretary of State for Transport and others, the Court of Appeal in England (the Court) heard an appeal in relation to a judicial review of the UK government’s Airports National Policy Statement (ANPS). The UK government had effectively provided its support for the construction of the third runway at Heathrow under the ANPS, which was the subject of appeal by a number of local authorities and environmental NGOs. In the first instance, these local authorities and NGOs were unsuccessful. However, the Court determined that, in making the ANPS, the Transport Minister had not taken into account the UK’s commitments in the UNFCCC Paris Agreement (the Paris Agreement). Therefore, the ANPS was considered illegal.

Heathrow Airport is the busiest two-runway airport in the world, and handles 70% of the UK’s scheduled long-haul flights. Arguably, the UK will not be able to sustain its position as a global “hub” unless it increases aviation capacity through the construction of a third runway at Heathrow. The Airport Commission (established by the UK government in order to consider aviation capacity) concluded in 2015 that there was a need for additional aviation capacity near London and that the Heathrow scheme for a third runway was the most viable option. While controversial, the UK government determined that it would use the ANPS to establish a framework through which an application could be made for development consent and, in October 2016, the UK government confirmed that the third runway at Heathrow was the preferred option.

The UK government’s decision attracted much criticism and was the subject of judicial review claims from a number of parties. Broadly, these claims related to ANPS’s incompatibility with: (i) the Habitats Directive; (ii) the Strategic Environmental Assessment (SEA) Directive; and (iii) the UK government’s commitments to climate change. In the first instance, the ANPS was upheld and the claims for judicial review were dismissed. However, in the Court, the claims succeeded on the UK government’s failure to take account of its own climate change policies in making the ANPS (broadly, the claims concerning the Habitats and SEA Directives failed).

The Court noted that the UK government had established its commitment pursuant to domestic legislation (the Climate Change Act 2008) to reduce greenhouse gas emissions by 80% (from their 1990 level) by 2050 (this target was recently elevated to a net-zero target by 2050). While this 80% target was considered ambitious at the time, it was not regarded as necessarily sufficient to meet the temperature targets under the Paris Agreement (i.e., to limit warming to well below 2 degrees Celsius and pursue efforts to limit warming to 1.5 degrees Celsius). Further, a number of ministers had made public statements to Parliament, after which it accepted that the goal of net zero would need to be enshrined in law.

However, in drawing up the ANPS, the responsible Secretary of State determined (on the basis of advice) that the UK government’s commitments under the Paris Agreement were not relevant considerations. However, the Court determined that the UK government’s Paris Agreement commitments constituted UK government policy and therefore needed to be taken into account in the relevant Planning Act. On this basis (and on the basis of additional related-considerations), the ANPS was considered unlawful, and the Court agreed to make a declaration in which the ANPS would have no legal effect “… unless or until the Secretary of State decides to conduct a review”. This review would need to take account of the UK government’s Paris Agreement commitments.

The Court was at pains to emphasise that it was not determining (and was in no position to determine) whether a third runway should be constructed at Heathrow. The UK government is in a position to reconsider the ANPS in light of its climate change commitments (including the Paris Agreement), however, the current government has confirmed that it has no plans to appeal the decision, effectively terminating the prospect of a third runway in the short- to medium-term (unless the airport operator is able to successfully appeal the Court’s decision to the Supreme Court).

While the Court may not be passing judgement on the politics of this matter, its decision has huge ramifications for infrastructure projects in the UK and further afield, as UK court decisions are influential in a number of commonwealth countries. Further, given the international environmental NGOs that were involved in this appeal, we can expect to see similar tactics adopted in relation to large infrastructure projects in Europe and elsewhere. Already there is suggestion that large road projects in the UK will be reconsidered in the context of the Paris Agreement, and we can expect to see examples of further scrutiny of infrastructure projects.