The lawsuit says Exxon engaged in a “longstanding fraudulent scheme” to deceive investors and analysts. : New York’s attorney general sued Exxon Mobil on Wednesday, claiming the company defrauded shareholders by downplaying the expected risks of climate change to its business. The litigation, which follows more than three years of investigation, represents the most significant legal effort yet to establish that a fossil fuel company misled the public on climate change and to hold it responsible.