A major hurdle was removed on Monday to a lawsuit seeking to hold fossil fuel firms responsible for climate change.

The U.S. Supreme Court declined to take up a challenge to a lawsuit brought by Minnesota Attorney General Keith Ellison against six companies connected to oil production. The companies had sought to have the lawsuit moved to federal court, and the court's decision to deny their petition keeps the case at the state level.

"[T]he defendants' behavior has delayed the transition to alternative energy sources and a lower carbon economy, resulting in dire impacts on Minnesota's environment and enormous costs to Minnesotans and the world," Ellison wrote in an emailed statement.

With the Supreme Court's decision, he added, "We can begin to hold these companies accountable for their wrongful conduct."

Minnesota's suit, filed in 2020, is one of several brought by cities, counties and states in the past seven years that seeks to hold oil firms accountable for their contributions to a warming planet. None has yet reached the point where each side is presenting evidence and arguments, however, because of repeated battles over whether the lawsuits should be heard in state or federal courts.

The Sabin Center for Climate Change Law at Columbia University lists 34 such cases in its database. The center tracks many kinds of climate litigation. Its executive director, Michael Burger, also works with the law firm handling Minnesota's litigation.

Minnesota's suit argues that the companies duped consumers by hiding evidence that burning fossil fuels heats the planet. The defendants include the American Petroleum Institute (API), ExxonMobil Corp. and Koch Industries.

Ryan Meyers, API senior vice president and general counsel, contended in an email that the lawsuits were meritless.

"We're disappointed by the Supreme Court's decision today to keep this litigation in state court," Meyers said. "But ultimately, climate policy is an issue for Congress to debate, not the court system."

The Supreme Court did not explain why it denied the petition, though its notice said that Justice Brett Kavanaugh would have allowed the challenge to be heard. Four of the nine justices must vote in favor for a case to get a hearing.

The court has made similar moves with several other climate change lawsuits that have reached it in the past year — denying hearings on jurisdictional issues and consistently sending the cases back to the state courts where they were originally filed.

Oil companies argue that the issues of climate change are broad-reaching and thus should be under federal jurisdiction. The firms also could have benefited from precedent in federal case law that may have dampened some of the states' and cities' claims.

Flint Hills Resources, a defendant in Minnesota's case and a Koch subsidiary that runs a refinery in Rosemount, said it also was disappointed by the move to keep the litigation in state court.

"This lawsuit against American energy companies is part of a broad, carefully coordinated campaign to circumvent the democratic process to alter national and global energy policy," wrote Jake Reint, a spokesman for Flint Hills, in an email. "Nevertheless, we will continue to defend our interests against these unfounded attacks and look forward to presenting our position in court."

ExxonMobil did not respond to a request for comment.

Margaret Barry, an environmental law writer with the Sabin Center, said that after the cases are returned to the state level, defendants typically have asked for them to be dismissed. So far, the cases mostly aren't being thrown out after these requests.

The case that has gone the furthest was filed by the city and county of Honolulu. That state's Supreme Court recently ruled that oil companies did not have the arguments necessary to dismiss the case.

Barry said it's possible that those defendants could try to bring that question, too, to the U.S. Supreme Court.