Heathrow expansion suffers crash landing

aeroplane takes off
Airlines aim to use 200 million tonnes of biofuels each year
'The bell is tolling on the carbon economy loud and clear.'

Imagine when we all start taking the Paris agreement into account.

Boris Johnson was facing significant embarrassment today after judges at the Court of Appeal in London ruled that his government decision to allow Heathrow airport to build a third runway is illegal, because it contravened its Paris Agreement commitments.

Johnson, the prime minister, promised he would “lie down in front of those bulldozers and stop the construction” of the runway back in 2015. The Tories then supported the plan but under his leadership was today  forced into a humiliating u-turn by the courts months before Britain hosts the COP26 climate conference.

Tim Crosland, from Plan B, the law charity that brought the challenge, said: “It’s now clear that our governments can’t keep claiming commitment to the Paris agreement, while simultaneously taking actions that blatantly contradict it.” He added: “The bell is tolling on the carbon economy loud and clear.”


Greta Thunberg, the teenage Sweedish climate campaigner, said: “Imagine when we all start taking the Paris agreement into account.”

Geraldine Nicholson, from local campaign group Stop Heathrow Expansion, said: “This is the final nail in the coffin for Heathrow expansion. We now need to make sure the threat of a third runway does not come back.”

The Conservative government under Theresa May published a national policy statement in 2018 which included approval for the third runway at Heathrow. But almost immediately charities including Plan B, Greenpeace and Friends of the Earth, alongside local residents, councils, and the Major of London launched legal challenges.

The High Court backed the government back in May 2019, but the case was taken to the Court of Appeal and today it was announced that the judges have found against the government. Lord Justice Lindblom said: “The Paris agreement ought to have been taken into account by the secretary of state. The national planning statement was not produced as the law requires.”

Lord Randall, a former Conservative MP and climate adviser to the former prime minister Theresa May, said: “This is an opportunity for Boris Johnson to put Heathrow expansion to bed and focus on the most important diplomatic event of his premiership, the UN climate summit in Glasgow in November.” He added: “It’s his chance to shine on the world stage.”


Today’s ruling is the first time anywhere in the world that the courts have used the Paris Agreement to prevent an airport going ahead. The government has set a legal target of reducing carbon emissions to net zero by 2050. This gives grounds to law charities and others to take court action. 

Margaretha Wewerinke-Singh is an international public law expert at Leiden University, in the Netherlands. She said: “Its implications are global. For the first time, a court has confirmed that the Paris agreement temperature goal has binding effect. 

Imagine when we all start taking the Paris agreement into account.

“This goal was based on overwhelming evidence about the catastrophic risk of exceeding 1.5C of warming. Yet some have argued that the goal is aspirational only, leaving governments free to ignore it in practice.”

Professor Corinne Le Quéré, from the University of East Anglia, said: “Government needs to put climate targets at the heart all big decisions, or risk missing their own net zero objectives with devastating consequences for climate and stability. I am relieved this is finally recognised in law.”

Luke Murphy, Head of the IPPR Environmental Justice Commission, said: "This landmark judgment should be the death knell for a scheme which is incompatible with tackling the climate emergency.

"The UK's legal commitment to net zero and the Paris Agreement must mean urgent and radical reductions in carbon emissions. Allowing Heathrow expansion which could have contributed to the near doubling in demand for flights was always totally inconsistent with that goal.

"All governments, businesses and investors around the world must now consider the precedent set by this judgment when taking decisions that impact our climate. It must mark the end of 'business as usual'. All policies from road building to trade deals must now be subject to the question - are they climate safe?"


The cost of building the third runway at Heathrow has been estimated at £14bn with the completion pencilled in for 2028. The airport claims a further 700 planes would land each day - raising concerns about the additional carbon emissions from the services.

Campaigners now have to wait and find out whether Johnson’s government will now give up on the third runway or attempt to redraft the policy statement so that it can permit the Heathrow expansion and also explain how the government will meet its Paris Agreement commitments.

A spokeswoman for Heathrow said: “We will appeal...to the supreme court...and are confident that we will be successful. Expanding Heathrow, Britain’s biggest port and only hub, is essential to achieving the prime minister’s vision of global Britain. We will get it done the right way.”

Grant Shapps, the transport secretary, said: “Our manifesto makes clear any Heathrow expansion will be industry-led. Airport expansion is core to boosting global connectivity and levelling up across the UK. We also take seriously our commitment to the environment.”

This Author

Brendan Montague is editor of The Ecologist.

More from this author