Heathrow airport outside of London is one of the busiest airports in the world, with 80 million passengers going through it each year. So when plans were announced to construct a third runway that would bring in 700 more planes per day, it was no surprise that environmentalists were outraged (and rightly so). Not only would the third runway bring in more planes and hence, more carbon emissions, but it would also cost a whopping £14 billion ($18bn).

Plan B, a legal charity, claimed the plans to build a third runway showed everyone that the UK is not taking the Paris agreement seriously, and it launched one of many legal challenges against the Heathrow plans along with Friends of the Earth, Greenpeace, and the mayor of London. The challenges were dismissed in the high court in May 2019 but the complainants took their cases to the court of appeal, which delivered its verdicts on Thursday.

The result?

The third runway has been ruled illegal and will not be built! The court ruled that the plans were illegal because ministers did not adequately take into account the government’s commitments to the Paris agreement and its responsibility to tackle the climate crisis.

According to Margaretha Wewerinke-Singh, an international public law expert at Leiden University, the implications of the ruling are “global.” It marks the first time in history that a major court ruling was based on the Paris agreement, confirming that the “agreement temperature goal has a binding effect.” The ruling also means that other controversial projects around the world could be halted because of the Paris agreement.

After the Heathrow ruling was made, Greta Thunberg said: “Imagine when we all start taking the Paris agreement into account.” Yes, Greta, we are with you on this one!