Young Portuguese citizens hold placards as they arrive at the European Court of Human Rights (ECHR) for a hearing in a climate change case involving themselves against 32 countries, in Strasbourg, eastern France, on Sept 27, 2023. (PHOTO / AFP)

Six young people from areas in Portugal ravaged by wildfires and heatwaves took 32 European governments to court on Wednesday, arguing their failure to act fast enough on climate change is a violation of their human rights.

The case - filed in September 2020 against the 27 EU member states as well as five other European countries - is the largest climate case ever to be heard by the European Court of Human Rights (ECHR) in Strasbourg.

If the complaint is upheld, it could result in orders from national courts for governments to cut carbon dioxide emissions blamed for climate change faster than currently planned

The court hearing started around 915 am local time (715 GMT) and is scheduled to end at 1615 pm. A ruling in the case is expected in the first half of 2024.

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With the support of the British-based Global Legal Action Network (GLAN), the Portuguese applicants, aged between 11 and 24, are seeking a legally-binding decision that would force states to act.

If the complaint is upheld, it could result in orders from national courts for governments to cut carbon dioxide emissions blamed for climate change faster than currently planned.

"Today we will stand up at the ECHR to argue for our rights and our future," the applicants, who are all attending the hearing in person, wrote on social media.

Gerry Liston, one of GLAN's lawyers, said that if the case were successful it would be up to national courts to enforce the rulings and that they would be provided with a roadmap to ensure enforcement was effective.

To show support, people of all ages gathered outside the court holding banners that read "Stand with youth" and "We are rooting for you".

'Unprecedented in scale'

The applicants argue climate change threatens their rights including to life, physical and mental wellbeing.

One of the six, 15-year-old Andre Oliveira, previously told Reuters their goal was to force governments to "do what they promised they would do", referring to the 2015 Paris Agreement to cut emissions to limit global warming to 2 degrees Celsius and ideally 1.5C. Current policies would fail to meet either goal, according to the United Nations' Intergovernmental Panel on Climate Change.

"Without urgent action to cut emissions, (the place) where I live will soon become an unbearable furnace," another applicant, 20-year-old Martim Agostinho, said in a statement.

Agostinho and three other applicants are from the central Portuguese region of Leiria, where two wildfires killed more than 100 people in 2017.

This photograph taken on Sept 27, 2023, shows an outside view of the European Court of Human Rights (ECHR), in Strasbourg, eastern France. (PHOTO / AFP)

More than 80 lawyers are representing the accused countries, while the applicants are being represented by six lawyers, resulting in what GLAN described in a statement as a hearing "unprecedented in scale".

Liston acknowledged "taking on the legal teams of over 30 very well-resourced countries" would not be easy.

Portugal's legal team has submitted to the court that it was committed to fight climate change and the applicants had failed to provide evidence of its direct impact on them.

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Britain argues the case is "inadmissible" for various reasons, including jurisdiction.

Climate litigation is growing, both in Europe and beyond.

Last month, a judge in Montana, in the United States, handed a historic win to young plaintiffs in a climate change case. In addition to Wednesday's youth case, there are two other climate cases pending before the ECHR's Grand Chamber.