In a significant challenge to the United Kingdom’s Supreme Court, several leading climate scientists have said a recent ruling it made on the expansion of London’s main airport, Heathrow, will cause serious damage to the global environment, urging it to rule that the government must respect the 1.5°C limit internationally agreed to rein in global heating.

Almost 150 lawyers, academics, and policy-makers from around the world have written to the court, urging it “to mitigate the profound harm” they say will be caused by its judgement allowing the government to go ahead with its plans to expand Heathrow.

“Recklessly ignoring the spirit and letter of the law of the Paris Agreement sends a message to the world that the UK has joined the ranks of the climate wreckers, betraying the world’s vulnerable countries and communities,” they add.

Signatories include the government’s own former chief scientist, Sir David King; Dr James Hansen, the former NASA scientist once hailed as one of the “true giants” of climate science; and Dr Jeffrey Sachs, the economist and former advisor to three United Nations Secretaries-General.

The Paris Agreement on climate change, reached in 2015, “aims to substantially reduce global greenhouse gas emissions and to limit the global temperature increase in this century to 2°C while pursuing means to limit the increase even further to 1.5°C.”

Although the UK is a signatory to the Agreement, and was a keen supporter of it six years ago, the present government appears unwilling to give it effect. At several points it has faced challenges from the charity Plan B, set up to support strategic legal action against climate change.

In February 2020, the Court of Appeal considered a case brought by Plan B, appealing against a previous High Court decision to allow the building of a third runway at Heathrow, an argument advanced by the then Transport Minister, Chris Grayling. The Court of Appeal heard evidence from a range of witnesses and found unanimously in favour of Plan B’s challenge to the government’s plans, setting a precedent with global implications.

It has since emerged that Grayling’s argument to the High Court had hinged on reliance (which Plan B says was not disclosed to the court at the time) on the higher tolerable temperature increase agreed in Paris, 2°C, which the charity says would condemn many millions of people to an intolerable future, rather than the less disastrous 1.5°C figure.

Prime Ministerial Assurance

There appeared at this point to be solid government backing for Plan B. Prime Minister Boris Johnson said he accepted the court’s ruling, telling Parliament March 4 that “we will ensure that we abide by the judgment and take account of the Paris convention on climate change.”

But the government told Plan B in August 2020 that the Paris Agreement does not apply to the domestic law of the UK, and is therefore irrelevant to government policy on how to rebuild the country’s economy after the chaos caused by the COVID-19 pandemic. So it argued that it was entitled to rely on the 2°C figure which Plan B insisted would mean global disaster.

The government’s critics say this argument is a strange one to use when the UK is poised to host the annual UN climate conference, COP 26, in Glasgow in November.

In December 2020, the Supreme Court ruled the plan to expand Heathrow was lawful, upholding the government’s assertion that the Paris Agreement was irrelevant—despite uncontested evidence the expansion would result in emissions of 40 million tonnes of carbon dioxide by 2050 from UK aviation alone. This would be clearly inconsistent with the more stringent and safer 1.5°C Paris temperature limit.

Facing Prison

The director of Plan B, Tim Crosland, a professional lawyer, already faces court action and a possible two-year prison sentence for revealing the decision of the Supreme Court while it was still under embargo, and not yet authorized for publication.

In a personal statement published on December 15, he said he had decided to break the embargo “as an act of civil disobedience. This will be treated as a ‘contempt of court’ and I am ready to face the consequences.

“I have no choice but to protest the deep immorality of the Court’s ruling…The Supreme Court’s judgment, which has legitimized Mr. Grayling’s use of the deadly 2˚C threshold, has betrayed us all.”

Crosland added that “the Heathrow case…was about much more than the third runway. Fundamentally, it was about the obligation of the government to tell the truth. It can’t keep telling us it’s committed to the Paris Agreement temperature limit if its actions say the opposite.” − Climate News Network