Minnesota Attorney General Keith Ellison on Wednesday sued ExxonMobil Corp., Koch Industries and the American Petroleum Institute, saying they have long deceived consumers over the effects of climate change.

The lawsuit, filed in Ramsey County District Court, includes claims of multiple violations of Minnesota laws, including fraud, deceptive trade practices and false statements in advertising.

"The defendants deceived, lied and misrepresented the effects of their product to the public," Ellison said at a news conference. "For 30 years, [they] made misleading statements about climate change."

The lawsuit seeks restitution for the alleged harms Minnesotans have suffered and also asks the defendants to fund a public-education campaign on climate change.

ExxonMobil said the Minnesota lawsuit was a "politically motivated campaign" against energy companies.

"Legal proceedings like this waste millions of dollars of taxpayer money and do nothing to advance meaningful actions that reduce the risks of climate change," the company said in a statement.

Wichita, Kan.-based Koch Industries owns the Pine Bend oil refinery in Rosemount through its subsidiary Flint Hills Resources.

Flint Hills, also named as a defendant, said it is reviewing the state's lawsuit. Pine Bend, which employs more than 1,000 people, is one of the largest refineries in the Midwest and makes the majority of gasoline used in Minnesota.

The American Petroleum Institute, a trade group, said in a statement that over the past 20 years the industry has provided "affordable, reliable American energy to U.S. consumers while substantially reducing emissions and our environmental footprint. Any suggestion to the contrary is false."

Ellison, asked for a dollar amount on damages he was seeking, said "it's going to be a lot." Asked if that number could be in the ballpark of the state's $7 billion settlement in 1998 with the tobacco industry, he said it "certainly could be."

The lawsuit is part of a wave of litigation aimed at oil companies for climate-change effects. At least 15 other plaintiffs — including the states of Massachusetts and Rhode Island, as well as cities and counties — have filed such lawsuits. None has resulted in a decision against oil companies.

Leigh Currie, an assistant attorney general, said Minnesota's lawsuit is most akin to a suit filed last year by the state of Massachusetts, which also alleged violation of consumer protection statutes.

Currie said the Minnesota suit is the first to name Koch Industries as a defendant.

Perhaps the best known climate-change lawsuit against the oil industry is a New York case against Exxon, which was decided in the company's favor in December.

The New York state Attorney General's Office claimed the oil giant defrauded investors of $1.6 billion by knowing but not disclosing the true costs of climate change. A Manhattan state court judge ruled that New York had failed to prove investors were deceived.

"That was an investor-based lawsuit," Ellison said. "This is consumer-based."

The lawsuit was applauded by several state environmental groups, including the Minnesota Center for Environmental Advocacy, Honor the Earth, Fresh Energy and MN350.

"We have a choice over freedom to profit or freedom to breathe," and the oil industry has chosen the former, said Sam Grant, executive director of MN350, at the Wednesday news conference announcing the lawsuit.

People of color — particularly black Americans and Indians — have been disproportionally impacted by the ills of climate change, he noted.

"The damage to indigenous people is rising," Winona LaDuke, director of Honor the Earth, said at Wednesday's news conference.

Wild rice, a sacred plant to Minnesota's Ojibwe bands, is at risk as climate change is driving wetter summers, she said. "That will be disastrous to our wild rice."

The lawsuit claims the oil industry knew as early as the 1950s of the potential for global temperature increases and a resulting rise in sea levels. The American Petroleum Institute was specifically aware of such conclusions by the mid-1960s, and Exxon's corporate predecessors soon thereafter, the lawsuit said.

"Throughout the 1970s, it was becoming increasingly clear that climate change could have serious implications for Exxon's business model," the suit said.

It went on to claim that a pattern of deception by the oil industry only intensified over the ensuing decades, including funding research on climate change denial.

From 1997 through 2017, "Koch-controlled foundations gave more than $127 million to groups that obfuscated climate science," the suit alleges.

Mike Hughlett • 612-673-7003