Bill Gates has joined a £3bn bidding war to buy the world’s largest private jet operator just as he prepares to publish his new book How to Avoid a Climate Disaster. Cascade Investment, the fund that manages much of Gates’s $134bn personal fortune, announced on Friday it had teamed up with US private equity firm Blackstone in a bid for British private jet operator Signature Aviation. The Cascade and Blackstone offer came just hours after rival American private equity firm Carlyle made an approach to buy Signature, which handles more than 1.6m private jet flights a year. Cascade is already the biggest investor in Signature with a 19% stake. According to a study by academics at Lund University, Gates is one of the world’s biggest “super-emitters” due to his regular private jet travel. He took 59 flights in one year travelling more than 200,000 miles, according to the report, which estimated that Gates’ private jet travel emitted about 1,600 tonnes of carbon dioxide. That compares with a global average of less than five tonnes per person. Researchers have found that private jets emit up to 40 times as much carbon dioxide per passenger than commercial jets. Gates, who says in the foreword to his forthcoming book that he has spent a decade investigating the causes and effects of climate change, did not respond to requests for comment about his views on the carbon footprint of private jets. The billionaire has previously said that owning private planes was his “guilty pleasure”. In a Reddit Ask Me Anything in 2014, Gates said: “Owning a plane is a guilty pleasure. Warren Buffett called his the Indefensible. I do get to a lot of places for Foundation work I wouldn’t be able to go to without it.”