Fossil fuel companies in California could face investigation under legislation introduced by a state senator who says the proposed law is designed to hold industry accountable for "many years of public deception" and fraud over the scientific evidence about climate change.

The Climate Science Truth & Accountability Act would extend the statute of limitations under California's Unfair Competition Law from four to 30 years, giving greater leverage to state and local prosecutors to file civil charges in connection with the conduct of fossil fuel companies going back decades.

The legislation, introduced by Sen. Ben Allen (D-Santa Monica), would give prosecutors authority to delve into the issues dating to the heart of the denial era.

The legislation was inspired by investigative news stories, including those by InsideClimate News (ICN), and an investigation by the Union of Concerned Scientists (UCS) that disclosed ExxonMobil and the oil industry were aware of the dangers of global warming from the burning of fossil fuels as far back as the 1970s.

The ICN stories and later articles by the Los Angeles Times in tandem with the Columbia University Journalism School—along with a UCS report last year—revealed that the company went on to spearhead industry efforts in the late 1980s to derail regulation of greenhouse gas emissions and cloud public understanding of climate science.

The bill takes aim at fossil fuel companies over concerns that they have deceived the public for decades about their products' impact on climate change, and seeks to hold them accountable.

Based on his review of the recent disclosures, Allen said there are serious issues that warrant investigation.

"I want to give law enforcement the tools they need to hold people accountable for their actions if that's where the evidence takes them," he said. "Certainly everything we've seen suggests there may be a really strong case."

'Unfair and Deceptive Practices'

Allen said the legislation is not a directive to law enforcement to pursue prosecutions, and he emphasizes the bill does not change the standard of proof or alter legal due process.

Yet a summary of the bill by Allen's office concluded: "Given the environmental, health, and economic impacts that Californians are already paying for as a result of the fossil fuel industry's many years of public deception and their efforts to block action on climate change, it is important to hold the industry responsible.

"Keeping the statute limited to only four years undermines the state's ability to hold fossil fuel companies responsible for their unfair and deceptive practices that extend back well beyond four years, as well as the damages and risks that Californians and everyone else must face for centuries to come."

Extending the deadline for filing environmental cases would expose fossil fuel companies like Exxon to greater liability, said Richard Frank, professor of Environmental Practice and Director of California Environmental Law and Policy Center at the University of California, Davis.

"If the statute of limitations is extended, that means a now powerful environmental prosecutorial tool will become even more powerful," said Frank, who served nearly 30 years as a deputy in the California attorney general's office.

The unfair competition statute allows the California attorney general, a district attorney, or a city attorney of a city with more than 750,000 people to bring legal action against a business that has committed "unlawful, unfair or fraudulent business act[s] or practice[s] and unfair, deceptive, untrue or misleading advertising," as it relates to climate change.

As the law stands now, it is difficult for prosecutors to file cases involving violations older than four years. That would change if Allen's bill becomes law.

"It would open up a much wider window for companies to be held accountable for their conduct," Frank said.

It could be applied to possible violations by ExxonMobil and other fossil fuel companies for making deceptive public statements about what it knew about climate change and any attempts to obfuscate the truth, Frank said.

Cases brought under the law are civil, not criminal. That means violations can result in hefty fines and court orders to halt the illegal conduct.

The law could also be employed in civil litigation by private citizens who can prove to a court they have sufficient connection to, and harm from, the alleged violations. The proposed law also would also apply to so-called "private party" cases, in which stockholders might sue a company.

The bill must make its way through several senate committees before coming up for a vote in June before the full body. If it passes, the legislation will be forwarded to the assembly for consideration and a vote later in the summer. A final bill, if passed by the Democratic-held senate and assembly, could be on Gov. Jerry Brown's desk by August.

Brown, also a Democrat, and state lawmakers have a history of taking steps to combat climate change and curb toxic carbon pollution. Most recently, Brown signed ambitious legislation to expand renewable energy use to 50 percent and double energy efficiency in buildings by 2030.

Exxon already is the target of an investigation by the New York attorney general's office. Investigators for Attorney General Eric Schneiderman have issued a subpoena demanding Exxon turn over documents related to its climate change studies, and the way the company represented that information to the public. During a press conference Tuesday with five other attorneys general and former Vice President Al Gore, Schneiderman confirmed that California Attorney General Kamala Harris has also launched an Exxon climate probe. The attorneys general of Massachusetts and the Virgin Islands announced their own investigations of the oil giant.

Adrienne Alvord, California and western states director of the Union of Concerned Scientists, said the proposed expansion of California's statute of limitations is vital because the state is already experiencing the costly, damaging effects of climate change.

"We want to ensure that the state has the ability to hold fossil fuel companies legally accountable for the decades of deception and damages they have caused to public health, property and the environment in California," she said.