Schoolgirl environmental activist Greta Thunberg has been described as suffering ‘mental abuse by manipulative adults’ by Jeremy Corbyn’s brother. Piers Corbyn, 72, is a climate change denier and adds that listening to Miss Thunberg, 16, was ‘deranged’ describing her as an ‘ignorant brainwashed child’. He tweeted a BBC News article about the teenager’s visit to the UK telling MPs they need to ‘listen to climate scientists’. He said: ‘Listening to an ignorant brainwashed child is deranged. I am an actual scientist of physics Meteorology, astrophysics and climate and say @GretaThunberg is wrong and suffers mental abuse by manipulative adults.’ Piers has previously claimed that climate change is a cover up to push up fuel prices and says global warming is a hoax. He called Extinction Rebellion protesters on Waterloo Bridge ‘deranged’ and staged a counter-protest with a banner calling carbon dioxide a ‘gas of life’.