Former Obama housing secretary Shaun Donovan says he’d be “the climate mayor,” but his multimillionaire dad, who’s funding his long-shot City Hall bid, is the opposite of an environmental steward. Michael Donovan — who has given $6.8 million through a super PAC, making him the single largest donor in the entire mayoral race — owns three homes, a gas-guzzling private jet, and once destroyed wetlands in front of his $18 million Bridgehampton estate. “If candidates are taking money from polluters, they are making a big mistake because people suffer,” said Maritza Silva-Farrell, head of the New York umbrella environmental group...