Thunberg has rarely been out of the headlines this year, thanks to campaigning. In recent weeks, she was named TIME's Person of the Year, the youngest person ever to be granted the accolade.
As a result of her prolific activism, the BBC announced earlier this year that she would take the helm for an episode of its flagship show.
"Our guest editor today is climate change activist Greta Thunberg," said the program's host during the broadcast.
"She's asked us to speak to scientists, fellow campaigners, and key players in the climate change debate, including Shell's director Martin Wetselaar and [governor of the Bank of England] Mark Carney himself.
"And we introduced Greta to another familiar - if slightly older - environmentalist."
Sir David Attenborough
That older environmentalist was Sir David Attenborough, who Thunberg interviewed during the show via her laptop and a studio in Broadcasting House in London.
Sarah Sands, editor of Today, told The Sunday Times: "It was moving to see Greta's visible pleasure in talking to Sir David. What struck me about her was her lack of personal vanity or even self-consciousness. She is not interested in introspection."
Sir David expressed his admiration for the teenager, saying: "She's achieved things that many of us who've been working for 20-odd years have failed to achieve. That is, [she] has roused the world."
You can listen to the episode here