Greta Thunberg’s climate protests and transatlantic boat journey feature in the trailer for a forthcoming documentary about her life.

The two-minute teaser for I Am Greta sees the teenage climate activist issue a warning about the fate of the planet.

“People always tell us that young people are going to save the world, but there is simply not enough time to wait,” she says.

Unseen footage from Swedish environmental filmmaker Nathan Grossman begins with Thunberg’s one-person school strike outside the Swedish Parliament.

Students around the world soon begin following her lead, staging regular large protests, and Thunberg is invited to speak at various conferences.

The film culminates with her voyage across the Atlantic to speak at the UN Climate Action Summit in New York City.

(Dogwoof/Nathan Grossman)

Last month, Thunberg joined other young activists for talks with German chancellor Angela Merkel regarding climate issues.

I Am Greta is produced by Cecilia Nessen and Fredrik Heinig.

It will be released in UK cinemas on October 16, following the film’s world premiere at Venice Film Festival this month.