While none of the other officials present, aside from Maura Healey of Massachusetts and Claude Walker of the Virgin Islands, announced inquiries of their own, Mr. Schneiderman said, “not every investigation gets announced at the outset.”

Image Former Vice President Al Gore joined Eric T. Schneiderman, New York’s attorney general, at a news conference announcing other states will join an investigation into whether Exxon Mobil lied to investors and the public about the threat of climate change.











Credit... Richard Perry/The New York Times

Mr. Schneiderman began his investigation in November. His staff is looking at whether statements the company made to investors about climate risks — some as recently as last year — conflicted with the company’s own scientific research.

Part of that inquiry includes the company’s funding, for at least a decade, of outside groups that worked to dispute climate science, even as its in-house scientists were describing the possible consequences of climate change, along with the areas of uncertainty.

The company has supplied thousands of documents in response to the inquiry. While the inquiry could be expanded to include other energy companies and trade organizations, none have been named so far.

Many legal experts have questioned whether the actions and statements by Exxon Mobil can be construed as criminal and outside the protections of the First Amendment.