The UK’s court of appeal has today ruled that plans for a third runway at London Heathrow airport are unlawful because they do not take into account government commitments relating to climate change.

”We have concluded, in particular, that the designation of the [plans] was unlawful by reason of a failure to take into account the government’s commitment to the provisions of the Paris Agreement on climate change, concluded in December 2015,” the summary of judgements states.

The ruling addressed a challenge – brought by a number of local authorities, the mayor of London, Greenpeace, Friends of the Earth, and Plan B Earth – to the UK government’s Airports National Policy Statement (ANPS), which was designated in mid-2018.

The UK’s Planning Act requires that the policy set out in the ANPS “must … include an explanation of how the policy… takes account of government policy relating to the mitigation of, and adaptation to, climate change”, the judgement explains.

The appeal court has ruled that the failure of the policy to address those issues “is legally fatal to the ANPS in its present form”.

Responding to the verdict, Heathrow says the issues raised are ”eminently fixable” and that it “will appeal to the Supreme Court on this one issue and are confident that we will be successful”.

The ANPS outlined plans for a third runway to be built at Heathrow amid capacity constraints at the UK’s busiest hub.

That plan was approved by the UK parliament in June 2018, with then-transport secretary Chris Grayling describing it as an “historic moment”.

The UK High Court ruled the government’s blueprint for expansion to be legally sound in May 2019, but the judgement was appealed.

Today’s appeal judgement stresses that the decision “is not concerned with the merits of expanding Heathrow by adding a third runway, or of any alternative project”.

It adds: “Those matters are the government’s responsibility and the government’s alone.”

The summary notes that the government does not intend to appeal the ruling.

UK prime minister Boris Johnson has previously expressed strong opposition to Heathrow expansion plans.