Last year the Supreme Court reversed a decision of the Court of Appeal and held that the Government policy on airport expansion at Heathrow was not unlawful on climate change grounds.
The policy decision under challenge was an Airports National Policy Statement (ANPS) made in 2018, which set out the decision-making framework within which further planning decisions on airport expansion would be taken.
In February, the Court of Appeal agreed with the claimants that the Government had failed to take into account the Paris Agreement on Climate Change, which was ratified by the UK in November 2016. This international Agreement commits parties to restrict temperature rise to well below 2°C above pre-industrial levels and to pursue efforts to limit the temperature increase to 1.5°C above pre-industrial levels.
The Government had decided not to appeal (perhaps signalling a change in policy), but the case was continued by Heathrow Airport.