Should inaction be a crime? A band of young Portuguese children are challenging European governments over insufficient climate action. Some say this is the only way to halt the crisis.
Six young people sue 32 nations over climate
Activists: The six Portuguese youths who have filed a case in the European Court of Human Rights. Glossary
Asthma - A common lung condition that can cause breathing difficulties.
Human rights - The basic rights and freedoms that belong to every person in the world, from birth until death. They apply regardless of where you are from, what you believe or how you choose to live your life. Some have called for animals and even natural phenomena like rivers to have some form of human rights.
Montana - A state in the northwest of the US known for its mountainous landscape.
Fossil fuels - Fuels made from decomposing plants and animals, including coal, natural gas and oil. These fuels release carbon dioxide, causing global warming.
Shareholders - People who own shares in a company. Owning a share means somebody owns a very small part of the company.