The New York attorney general has begun a sweeping investigation of Exxon Mobil to determine whether the company lied to the public about the risks of climate change or to investors about how those risks might hurt the oil business.

According to people with knowledge of the investigation, Attorney General Eric T. Schneiderman issued a subpoena Wednesday evening to Exxon Mobil, demanding extensive financial records, emails and other documents.

The focus includes the company’s activities dating to the late 1970s, including a period of at least a decade when Exxon Mobil funded groups that sought to undermine climate science. A major focus of the investigation is whether the company adequately warned investors about potential financial risks stemming from society’s need to limit fossil-fuel use.