Greta: 'People are underestimating the force of angry kids!'
Greta Thunberg has arrived in Portugal ahead of her visit to a big climate meeting.
And she had some strong words for world leaders! She says she wants adults to listen to the voices of young people and to pay more attention to the scientists and climate experts who say more needs to be done to protect the environment.
Watch what she has to say and find out more here: