The historic trial is the first time so many countries will have to defend themselves in front of any court in the world. All 27 European Union member states, the UK, Turkey, Russia and Norway are among the defendants.
The Portuguese youth, aged between 11 and 24, say governments’ inaction on climate change breaches their human rights and discriminates against young people.
Devastating heat and wildfires in Portugal are restricting their ability to sleep and exercise, harming their physical health and causing mental distress. They also say that climate anxiety is now widespread among their generation.
"The fires are very close to where I live," Martim Duarte Agostinho, 20, told Euronews in Strasbourg ahead of the trial.
"Fires that have already put my life and the lives of my sisters at risk. School days have been lost because of one of my minor respiratory illnesses," he explained.
Dunja Mijatović, Human Rights Commissioner of the Council of Europe, intervened as a third party during the first day of the trial on Wednesday.
She told Euronews that "the time is right, that we move from words to deeds."
"We know there are numerous resolutions, numerous conventions, wonderful words on paper. But the action is missing," she added.
Climate change knows no borders
A contentious issue will be whether the court accepts that countries other than Portugal have obligations to protect the six young people from the devastating effects of climate change.
The youth say that while they live on the front line of the climate crisis, with Portugal facing record-breaking heat and deadly wildfires in recent years, global warming knows no borders. If the planet continues to warm on its current course, Portugal will face heatwaves of 40°C lasting for a month or more.
Previous ECHR rulings say countries are responsible for the human rights of people outside its borders in “exceptional cases”.
But the defending governments claim the young people have not provided sufficient evidence that there is a “direct causal link” between the governments’ climate policies and the harm they have suffered. They say no sufficient medical evidence has been presented to demonstrate damage to physical and mental health.
They also rebuke their responsibility to protect the human rights of citizens beyond their own jurisdictions.
A legal landmark
According to the Portuguese youth, their right to life, family life, and privacy, as enshrined in the European Convention on Human Rights, are being violated.
They also say that governments are breaching their right to be free from torture, inhuman or degrading treatment, which was included upon the judges’ own recommendation. A positive outcome would make legal history, as the court has never found violations of this specific human right in a case concerning the environment.
According to Kate Higham, Policy Fellow at the Grantham Institute, London School of Economics, a positive decision could be used to “strengthen the arguments in domestic climate cases against governments, and potentially companies.”
“The case could represent a breakthrough for climate litigation. If it's successful on all the grounds, defendant governments would need to change course and cut emissions faster to show compliance with the ruling,” she said.
The case will be heard by a panel of 17 judges in the Strasbourg-based court, which earlier this year heard its first-ever climate lawsuits against European countries.
In March, a group of senior Swiss women and a former French mayor sued their governments for lack of decisive climate action.
Governments’ deadly inaction
The youth’s legal team will argue the 32 governments’ insufficient climate targets are directly responsible for the young people’s rapidly degrading quality of life.
“European governments’ climate policies are consistent with a catastrophic 3 degrees of global heating this century,” Gerry Liston, senior lawyer for GLAN, explained.
“For the brave youth-Applicants, that is a life sentence of heat extremes which are unimaginable even by today’s rapidly deteriorating standards,” he added.
The European Commission has been granted permission to intervene in the case as a third party.
In its written observations to the court, it claims the EU is “leading the efforts to achieve the objectives of the Paris agreement by setting itself even more ambitious GHG (greenhouse gas) emissions targets and by going beyond the minimum necessary to comply with its obligations under that agreement.”
The bloc also refers to its member states’ national energy and climate plans (NECPs), as proof of their roadmap to mitigate the devastating effects of climate change.
But countries, including France and Germany, have recently missed an EU deadline to update their NECPs.
Industry is also warning that the EU is set to miss its 2030 green energy goals.
A recent report by the German Federal Environment Agency (UBA) shows Germany is likely to miss its goal to cut greenhouse gas emissions by 65% by 2030.
The case comes as other European countries, such as the UK, roll back on key climate policies, including delaying the phaseout of diesel and petrol cars by five years to 2035.