Six young people from Portugal will take on 32 countries in the European Court of Human Rights (ECHR) on Wednesday for not doing enough to stop global warming. The unprecedented hearing is the world's largest climate legal action to date.
The move to file a complaint with the Strasbourg-based court ECHR was sparked by the massive wildfires that struck Portugal in 2017, killing more than 100 people and charring swathes of the country.
The group, aged 11 to 24, say they are suffering from anxiety over their health and "having to live with a climate that is getting hotter and hotter" with more natural disasters.
Some plaintiffs claim allergies and breathing problems both during the fires and after, conditions at risk of persisting if the planet keeps warming.
"European governments are not managing to protect us," said Andre Oliveira, 15, one of the six involved.
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Andre and his fellow plaintiffs say the 27 European Union member states along with Russia, Turkey, Switzerland, Norway and Britain have all failed to sufficiently limit greenhouse gas emissions, affecting their life and health.
In concrete legal terms, they complain of infringements of their rights to life and respect for private life - articles 2 and 8 of the European Convention on Human Rights.
'Matter of priority'
"There have been cases taken by young people about climate change in other courts before, but this is the first to be heard by the ECHR related to the rights of young people," said Gerry Liston, a lawyer with the British-based Global Legal Action Network (GLAN), which is representing them.
If they win, nations would have to "rapidly accelerate their climate mitigation efforts", Liston added.
The ECHR is taking the case seriously, labelling it a "matter of priority" and passing it to the body's top judges in its Grand Chamber.
The case is "unique", especially given the number of states accused at once and the importance of the climate.
Until now, the court's environmental decisions have not covered global warming, dealing with issues like natural disasters and industrial pollution.
But judges must first rule on the admissibility of the case, since the Portuguese youths filed directly to the ECHR without first seeking recourse in domestic courts.
They argue that trying to file separate cases in all 32 countries would be an "excessive and disproportionate burden" on an issue requiring urgent attention.
Two other climate cases involving France and Switzerland were examined by the ECHR in March, though no rulings have been handed down.