The state of California has sued five of the largest oil and gas companies in the world, alleging that they engaged in a “decades-long campaign of deception” about climate change and the risks posed by fossil fuels that has forced the state to spend tens of billions of dollars to address environmental-related damages.

State Atty. Gen. Rob Bonta filed the lawsuit Friday in San Francisco Superior Court alleging that Exxon Mobil, Shell, Chevron, ConocoPhillips, BP and the American Petroleum Institute have known since at least the 1950s that the burning of fossil fuels would warm the planet but instead of alerting the public about the dangers posed to the environment they chose to deny or downplay the effects.

“Oil and gas companies have privately known the truth for decades — that the burning of fossil fuels leads to climate change,” Bonta said in a statement, “but have fed us lies and mistruths to further their record breaking profits at the expense of our environment. Enough is enough.”

“With our lawsuit, California becomes the largest geographic area and the largest economy to take these giant oil companies to court,” he added. “From extreme heat to drought and water shortages, the climate crisis they have caused is undeniable.”

Attorneys for the defendants could not immediately be reached for comment.

Bonta said he is seeking nuisance abatement through the creation of a fund to finance climate mitigation and adaptation efforts; injunctive relief to both protect California’s natural resources from pollution, impairment, and destruction, as well as to prevent the companies from making any further false or misleading statements about the contribution of fossil fuel combustion to climate change. The suit also seeks damages and penalties.

California has spent tens of billions of dollars to adapt to climate change and address the damages climate change has caused so far, the complaint said, and it will have to spend far more than that in the years to come.

Bonta’s action was joined by Gov. Gavin Newsom who in 2019 began calling for plans to phase out oil production in California, citing the increasingly harmful effects of global warming.

His actions raised ire in petroleum company boardrooms, enraged Kern County officials and left small-town governments at the southern end of the San Joaquin Valley grappling with shrinking tax rolls.

“For more than 50 years, Big Oil has been lying to us — covering up the fact that they’ve long known how dangerous the fossil fuels they produce are for our planet,” Newsom said on Saturday.

“California taxpayers,” he added, “shouldn’t have to foot the bill for billions of dollars in damages — wildfires wiping out entire communities, toxic smoke clogging our air, deadly heat waves, record-breaking droughts parching our wells.”

Kassie Siegel, director of the Center for Biological Diversity’s Climate Law Institute, welcomed the lawsuit as part of a far wider campaign to put pressure on toxic emitters within California’s vast industrial complex.

“As the world’s fifth-largest economy, and the nation’s most populous state,” she said, “California is uniquely positioned to hold Big Oil accountable for its endless lies and malicious blocking of climate action.”