The Massachusetts Supreme Judicial Court has handed ExxonMobil another defeat in the company's legal battle to head off climate investigations into whether it misled investors and the public about the risks of climate change.

The court ruled Friday that Attorney General Maura Healey has the authority to compel Exxon to turn over records showing whether the oil company's marketing or sale of fossil fuel products violated the state's consumer protection law.

In its 32-page opinion, the state's highest court ruled that Healey may proceed with enforcing a civil investigative demand—similar to a subpoena—for Exxon documents related to climate change dating back four decades. Her office issued the demand nearly two years ago.

The court rejected each of Exxon's arguments that Healey's investigation should be stopped. Among other things, Exxon had claimed that Healey was biased based on her participation in a coalition of attorneys general formed to look into the fossil fuel industry's actions, and that the company was outside of Healey's reach because the corporation did not do business in the state, though it has 300 Exxon and Mobil franchise gas stations in Massachusetts.

The court also made a strong statement about climate change, writing: "The Attorney General's investigation concerns climate change caused by manmade greenhouse gas emissions—a distinctly modern threat that grows more serious with time, and the effects of which are already being felt in Massachusetts. More particularly, the investigation is premised on the Attorney General's belief that Exxon may have misled Massachusetts residents about the impact of fossil fuels on both the Earth's climate and the value of the company."

A spokesman for Exxon did not respond to a request for comment.

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Healey's investigation had been stalled while Exxon's objections made their way through federal and state courts. Both courts have now ruled that the investigation may continue.

"For the second time this month, Exxon's scorched earth campaign to block our investigation has been entirely rejected by the courts," Healey said in a statement. "Now Exxon must come forward with the truth, what it knew about climate change, when, and what it told the world. The people of Massachusetts—and people everywhere—deserve answers."

Although the recent court rulings offer no opinion on Exxon's conduct, they validate the watchdog role of the attorneys general to hold the company accountable, said David Shapiro, an assistant professor of financial forensics at John Jay College of Criminal Justice in New York.

The attorneys general are now free to ask the questions and demand answers to what Exxon knew, when they knew it, and what they did about it, Shapiro said.

"It's important to get to the truth of the process," he said. "This offers the opportunity to determine whether there was a state of mind to mislead and whether management puts its finger on the scale to tip opinion one way or another."

Finding Out What Exxon Knew

The ruling clears the way for Massachusetts investigators to compel Exxon to produce a trove of documents sought by a 2016 civil investigative demand.

Among the records prosecutors want to see are Exxon documents back to 1976 concerning the company's research into carbon dioxide emissions and the effects of the greenhouse gas has on the climate. Further, investigators are seeking documents recounting how Exxon officials communicated with investors about the environmental impacts of greenhouse gas emissions, including the risks associated with climate change.

They also want records of Exxon's association with organizations such as the American Legislative Exchange Council (ALEC) and The Heartland Institute, which have a history of climate skepticism and pushback against climate regulations.

Healey said at a news conference on Friday that she expects Exxon to begin complying with her demand for documents, and she said her office is prepared to relentlessly follow the trail. "We will go where the facts lead us," she said. "There is an awful lot we don't know."

Federal Judge Also Rejected Exxon's Arguments

The ruling follows a scathing denunciation of Exxon by a federal judge in New York who rejected the company's motion for an injunction to halt investigations by Healey and New York Attorney General Eric Schneiderman.

In her ruling on March 29, U.S. District Judge Valerie Caproni called out the oil giant for "running roughshod over the adage that the best defense is a good offense."

Caproni rejected as "implausible" Exxon's contention that it was being harassed by Healey and Schneiderman as of part what it called a conspiracy to deprive the company of its First Amendment rights and silence its views on climate change.

Healey's office notified the Massachusetts Supreme Judicial Court of Caproni's ruling, though it's unclear if the state justices considered it.

The Massachusetts court, in its ruling, wrote that Healey's investigation started after investigative reporting published in 2015—first by InsideClimate News, and later the Los Angeles Times—showed through Exxon's own internal documents how the company had long understood the consequences of global warming but had engaged in a campaign to cast doubt on the science.

Healey opened her investigation in 2016 by issuing the investigative demand in connection with potential violations of the Massachusetts consumer protection statute. The investigation focused on whether Exxon may have misled consumers or investors with respect to the impact of fossil fuels on climate change, and climate change-driven risks to Exxon's business.

Exxon went to court almost immediately to try to block the investigation, starting what has become a drumbeat defense against multiple investigations: its claim that it was the innocent target of a political vendetta. Several courts have now rejected that argument.