On February 27, Britain’s Court of Appeal ruled against an $18 billion proposed expansion of Heathrow Airport, stating policymakers had failed to consider the U.K.’s climate change commitments under the 2015 Paris Agreement when designing the project (AP News, Reuters, The Guardian, New York Times). The decision is the first major ruling in the world to be based on the Paris climate accords (The Guardian). 

While Heathrow Airport has announced plans to challenge the ruling, the U.K. government will not appeal the verdict. Transport Minister Grant Shapps stated, “We take seriously our commitments on the environment, clean air and reducing carbon emissions. We will carefully consider this complex judgement and set out our next steps in due course” (Reuters). 

The ruling marks the latest in a decades-long battle over the addition of a third runway to Heathrow Airport. The project was most recently approved in 2018 and later appealed by interest groups including local residents, local officials such as London Mayor Sadiq Khan, and environmental groups (The Guardian).  

Supporters of the expansion say Britain will need to increase trade with countries outside of Europe in order to stay economically competitive after Brexit. Heathrow Airport, the U.K.’s biggest port by value, already runs at full capacity (AP News, Reuters). Critics say expanding Heathrow Airport’s capacity by over 50% adds pollution, noise, and congestion for London residents and jeopardizes the U.K.’s commitment to reach net-zero carbon emissions by 2050 (New York Times, AP News).