• The state of California is suing five big oil companies and the trade group that represents them, alleging decadeslong deception about the correlation between fossil fuel production and climate change.
• The lawsuit was filed on Friday by the California Attorney General in San Francisco superior court.
• California's complaint joins a wave of climate litigation nationwide but could further open the legal floodgates on such action against oil firms.

The state of California on Friday filed one of the most significant cases against major oil companies for what it sees is their role in perpetuating climate change.

The 135-page legal complaint, filed through the office of California Attorney General Rob Bonta in San Francisco superior court, alleges that five big oil companies along with the American Petroleum Institute, a trade organization that represents them, orchestrated a decadeslong disinformation campaign to hide the correlation between fossil fuel production and climate change.

The state claims that this intentional cover-up has gone on since at least the 1970s and has delayed the public's response to climate change, exacerbating extreme natural disasters and incurring tens of billions of dollars in recovery costs.

The oil companies named as defendants are BP, Chevron, ConocoPhillips, Exxon Mobil, and Shell. The state is seeking an abatement fund paid for by the defendants that will finance recovery efforts for the future damage of human-caused climate change. It also asks that the oil companies and their trade group pay a share of the damages from extreme weather disasters worsened by climate change.

It's the latest in a slew of climate litigation against oil companies in cities nationwide. But California's entrance into this legal arena is particularly damning.

The sheer number and magnitude of extreme weather events in California means the oil companies face a heftier price tag in damages if they lose the case than they might in smaller states.

"California getting involved is a big signal to other jurisdictions around the country that they think this is a winning case," said Korey Silverman-Roati, a senior fellow at Columbia University's Sabin Center for Climate Change Law. "That could in turn motivate more people, more states, more cities, more counties to file."

The lawsuit is also notable for its timing. It comes after an April Supreme Court ruling denied five oil companies' appeals to have similar cases heard in federal rather than state court. Federal appeals can sometimes be "a quick path to dismissal," according to Silverman-Roati, but with this ruling the California suit will more likely remain on the state level.   

California Gov. Newsom highlighted his support for the lawsuit in a Saturday tweet.

California is suing Big Oil for lying about climate change.

We're taking five major oil companies to court for wreaking havoc on our planet and lying to people about the dangers of fossil fuels.

It’s time they pay their fair share. pic.twitter.com/hu1Glnq4Da

— Office of the Governor of California (@CAgovernor) September 16, 2023

Friday's complaint is demanding remedies based on seven claims, including that the oil companies and the API engaged in false advertising and the destruction of natural resources.

"Their deception caused a delayed societal response to global warming," the attorney general's office wrote in the lawsuit. "And their misconduct has resulted in tremendous costs to people, property, and natural resources, which continue to unfold each day."

The defendants have denied the allegations, claiming the lawsuit is politically motivated.

In a statement, Chevron, a California-based company, said climate change "requires a coordinated international policy response, not piecemeal litigation for the benefit of lawyers and politicians."

API Senior VP Ryan Meyers echoed this sentiment: "This ongoing, coordinated campaign to wage meritless, politicized lawsuits against a foundational American industry and its workers is nothing more than a distraction from important national conversations and an enormous waste of California taxpayer resources."

Shell, based in the U.K., maintained that its position on climate change "has been a matter of public record for decades." BP, which is also based in the U.K., declined to comment, and ConocoPhillips and Exxon Mobil, both based in Texas, did not immediately respond to a comment request.

"There's precedent for these major tort movements against industries marketing their products as safe when in fact they were harmful," said Silverman-Roati.

The California suit emulates the legal model of past litigation against opioid and tobacco companies, citing false advertising that their goods were safe. More recently in 2019, California counties and cities settled a case against lead paint makers for $300 million to finance an abatement fund to address dangers related to lead paint.

Silverman-Roati added: "State courts have a history of being able to adjudicate whether company actions to obfuscate the dangerousness of their products are in fact illegal. So we will see that play out in this legal fight."