Could Heathrow airport expansion ruling set a climate precedent?

UK court declares planned third runway unlawful, the world’s first major legal ruling to be based on the Paris Agreement
<p>&nbsp;A plane&nbsp;after taking off&nbsp;from Heathrow airport&nbsp;(Image: Alamy)</p>

 A plane after taking off from Heathrow airport (Image: Alamy)

Plans by the UK to expand its biggest airport have recently been declared unlawful because they failed to take the Paris Agreement into account.

Climate activists had taken the government to court in a last-ditch effort to stop the building of a third runway at Heathrow, a major international airport situated to the west of London.

The ruling, by three Court of Appeal judges, said the Paris Agreement “ought to have been taken into account” when the government signed off its policy favouring the development in 2018, but was not.

“The judgement criticised the government for failing to question how an increase in emissions from an expanded Heathrow could be reconciled with its commitment to reduce emissions under the Paris Agreement,” says Tim Johnson, director of the Aviation and Environment Federation (AEF).

The decision is thought to be the first major legal ruling in the world based on the Paris Agreement. It is particularly significant because the treaty does not form part of UK law.

The challenge had previously been dismissed in the High Court in May 2019, but campaign group Plan B had continued with the case, bringing it to the Court of Appeal in February.  

“Some sanity is finally prevailing,” said Tim Crosland, director of Plan B, in a statement. “It’s now clear that our governments can’t keep claiming commitment to the Paris Agreement while simultaneously taking actions that blatantly contradict it.”

A number of other challenges had also been brought on various grounds by several London boroughs, London Mayor Sadiq Khan and other environmental groups.

The proposal to build a third runway at Heathrow has for years pitted pro-business groups who claim it is essential infrastructure for the UK’s future economy against environmentalists and London residents who say its benefits are overstated and its risks downplayed.

“This ‘benefit to the economy’ versus the impact on people's quality of life and the environment has never been resolved, and many west London local authorities, community groups and the mayor of London remain opposed,” says the AEF’s Johnson.

The airport is already the UK’s largest single source of carbon emissions, and a third runway would mean an extra 700 planes per day passing through it. It would also mean greater levels of local air and noise pollution in a built-up area that is already highly exposed to these problems. In addition, three villages would need to be partially demolished to make way for the runway. Their residents have fought furiously against the expansion.

Residents of Sipson village, beside Heathrow airport, protest against the third runway back in 2008 (Image: Alamy)

Over the years, three separate independent reviews have all concluded the Heathrow expansion was necessary to meet demand, says Johnson. However, fluctuating political support has meant it never advanced to a formal planning application.

The government said it would not appeal the ruling, although Heathrow airport itself said it will take it to the Supreme Court, the UK’s highest court of appeal.

The government could now decide to draw up a new policy document that tries to better address climate change. But commentators say the legal setback now offers Prime Minister Boris Johnson the chance to quietly drop the scheme. When he was London mayor, Boris Johnson opposed the expansion, famously declaring he would “lie down in front of those bulldozers” to stop the third runway’s construction. He has been far quieter in his opposition since he entered the cabinet and skipped the key vote approving the project, but still maintains he opposes it.

The UK is responsible for 4% of global aviation emissions, with only the United States (24%) and China (13%) emitting more. Globally, aviation emissions are growing fast, and the UK is no exception. Like other countries, it has struggled to address the climate impacts of the sector, with fuel efficiency improvements in planes tending to fall far behind the growth in flight numbers. UK industry body Sustainable Aviation recently set a target for net-zero emissions by 2050, but environmental groups have been sceptical of the sector’s efforts to actually reduce emissions.

The distribution of those who take flights is very uneven in the UK: around 15% of people in England, Scotland and Wales take 70% of flights, an inequality that has sparked calls for a frequent-flier levy.

But even if the Heathrow expansion does not go ahead, the door is still open to develop other airports in the UK, which wants to maintain its status as a “global hub for aviation”. The ruling may put plans to expand Gatwick, a smaller London airport, back on the table, for example. Others argue regional airports need more flights.

However, the court’s decision on the basis of the Paris Agreement creates a strong precedent for any airport expansion to more fully address climate change. There are also implications for other infrastructure projects in the UK. Shortly after the ruling was made, sustainability group Transport Action Network said it is considering challenging the government’s £29 billion (US$38 billion) road expansion programme in court on the same grounds as Heathrow.

“The decision is not just about Heathrow but broader ways in which our planning processes must now be revamped to take climate change laws and policy into account,” says Farhana Yamin, an international climate lawyer and founder of the Track 0 initiative.

The ruling could also have implications outside the UK for other countries trying to be compliant with the Paris climate deal, says Yamin.

“Paris was always meant to set international policy and then be implemented nationally, but governments were ignoring the ‘well below 2C’ and 1.5C goals in their assessments,” she says. “The court says that cannot continue. It has made me very happy because that is how international law works.”

Courts around the world may now be more willing to draw directly upon the Paris Agreement as they consider comparable cases in their jurisdictions, agrees Jonathan Church, a lawyer with the activist legal charity ClientEarth. He adds that public interest litigators will also be emboldened to ask courts to do this.

“This decision will have global implications in reframing the significance of the Paris Agreement in the minds of activists, lawyers and governments,” he says. “It is less about increasing ambition and more about narrowing the gap between the ambition of the Paris Agreement and the action that governments take in the real world.”