London, Dec 30 (TIWN) The father of Greta Thunberg, the 16-year-old Swedish environment activist, has said that she "changed" and has become "very happy" as a result of her activism that has contributed towards a global movement demanding world leaders to take action over climate change.

Speaking to the BBC to mark his daughter’s guest-editing slot on the Today programme, Svante Thunberg revealed he thought it was a “bad idea” for Greta to stage the school strike that catapulted her into the public eye.  The programme also featured a discussion between Greta Thunberg and the veteran naturalist Sir David Attenborough, in which the latter praises the teenager for raising awareness of the climate crisis.  She had “achieved things that many of us who have been working on it for 20-odd years have failed to achieve – that is you have aroused the world”, said Sir David, adding that she was the main reason climate was discussed during the British election campaign.