Massachusetts became the latest state investigating whether Exxon Mobil Corp. misled investors and the public about how climate change may affect its business.

News of the state’s probe came as part of a larger announcement on Tuesday by attorneys general from California to New York who are joining forces to fight global warming and look into whether companies have understated its effects.

The group of 17 states and territories may jointly investigate the climate change disclosures of individual oil and natural gas companies, according to a statement from New York Attorney General Eric Schneiderman.

Any resulting litigation could resemble that brought by the Justice Department against cigarette makers in 1999, said Sharon Eubanks, who served as the U.S.’s lead lawyer in that case, and now works in private practice with Bordas & Bordas.

“There are a lot of similarities between federal tobacco litigation and activities we know Exxon has engaged in at this point,” Eubanks said in a phone interview. The government would most likely try to bring civil racketeering claims, attempting to show that individuals at Exxon funded front groups to undermine science, or defrauded investors by making business decisions based on what it knew, but didn’t disclose, about climate change, she said.

Massachusetts joins New York in looking into whether Exxon’s climate-change disclosures were misleading. New York’s probe has been active since at least November, when Schneiderman’s office subpoenaed Exxon documents including communications with trade groups.

The group formed Tuesday is part of an even broader coalition of 25 states, cities and counties defending President Barack Obama’s plan to cut emissions from U.S. power plants and generally fighting for reductions in greenhouse-gas pollution.

‘Politically Motivated’

Suzanne McCarron, Exxon’s vice president of public and government affairs, described climate-change allegations leveled against the company as “politically motivated and based on discredited reporting funded by activist organizations.” The company is “assessing all legal options,” she said in an e-mailed statement.

New York’s investigation followed articles by InsideClimate News and the Los Angeles Times alleging Exxon’s scientists discovered evidence that man-made emissions were changing the climate as far back as 1977.

In a series of blog posts last year on a website known as “ExxonMobil Perspectives,” the company’s then-General Counsel Kenneth Cohen characterized the reports as products of “anti-oil and gas activists” who “cherry-picked documents” to distort the Irving, Texas-based company’s treatment of climate research.

More States

“With more states jumping on board, these investigations are sure to generate some serious waves,” May Boeve, executive director of 350.org, an environmental advocacy group, said in an e-mailed statement. “We’ll be looking for the Department of Justice and many more cities and states to get involved.”

Attorneys general William Sorrell of Vermont, George Jepsen of Connecticut, Brian E. Frosh of Maryland and Mark Herring of Virginia were among those in New York on Tuesday for the announcement of the climate change coalition.

“With gridlock and dysfunction gripping Washington, it is up to the states to lead on the generation-defining issue of climate change,” Schneiderman said in the statement. “Our offices are seriously examining the potential of working together on high-impact, state-level initiatives, such as investigations into whether fossil fuel companies have misled investors about how climate change impacts their investments and business decisions.”

In California, state senators are considering a bill that would extend the statute of limitations on a law that prohibits companies from engaging in deceptive or misleading advertising to 30 years from four years. The legislation must be taken up in committee before it can head to a floor vote.

“Our environment and economy face grave risks from climate change, including unprecedented heat and wildfires, severe drought and sea level rise,” the bill’s author, Senator Ben Allen of Santa Monica, said in a statement. “This legislation will give law enforcement the tools to hold companies accountable for hiding evidence of their products’ devastating impacts and for their role in delaying action to address this crisis.”