Several Supreme Court Justices appeared skeptical Monday of a request from oil companies to preemptively block a climate change lawsuit that could hold them liable for climate damages. Many of the justices raised questions about the court’s ability to even take up the case at this time. "A number of the discussions that you've had with my colleagues make me think that we're really early in this case – that this is sort of premature from the standpoint of this court exercising its jurisdiction," liberal Justice Ketanji Brown Jackson told Suncor Energy lawyer Kannon Shanmugam.

While Jackson’s skepticism is not necessarily a surprise, several of her conservative colleagues, namely Justices John Roberts and Neil Gorsuch, also asked tough questions of the fossil fuel firm. Suncor, alongside ExxonMobil, has asked the high court to toss a ruling from the Colorado Supreme Court that allowed a suit to proceed. The suit alleged that the energy companies misled the public about their products’ relationship to climate change and created a public nuisance. The case could have implications for similar litigation around the nation, as states and localities have sued oil and other fossil fuel companies seeking compensation for damages they’ve suffered because of climate change.

The court could rule one of three ways: The justices could expressly block the case or expressly allow it to proceed, or they could rule that they don’t have jurisdiction at this point, which could allow the case to move forward, but could see the issue back at the high court at a later date. Either of the latter two outcomes could be at least a partial win for the localities, as they would be able to move ahead with their case — at least in the short term.

Boulder needs only four votes in its favor to win the case, as conservative Justice Samuel Alito has recused himself. The fossil fuel firms would need five justices on their side because in a split decision, the lower court’s ruling would stand.

As Shanmugam argued that Colorado state law shouldn’t apply to the actions of out-of-state energy companies, Roberts asked about the potential for someone in one state to throw a rock over the border of the state they’re in and hit a person in another state. When the oil company’s lawyer noted that planet-warming emissions are not necessarily directed at Colorado, Roberts replied, "If you're in [State] B and you're aiming at [State] C, but you hit somebody in [State] A, that doesn't make a difference, does it?”

However, it’s not entirely clear which way the court will rule, as the justices also asked tough questions of Boulder County. “Presumably, if you prevail the next day, a municipality in every single state will file a lawsuit,” Roberts said. “How would you think that will work out on the ground?”"There are other examples where a course of conduct causes mass liability across the nation in asbestos, in other kinds of product liability suits, and courts deal with them through litigation,” Boulder lawyer Kevin Russell responded.

"I think maybe asbestos is a little different, since ... it doesn't have to be applied as broadly after a decision of the sort you're talking about,” Roberts replied. “But there's always going to be greenhouse gas emissions affecting every state.”The justices also considered whether the case was different from state-level suits related to tobacco or opioid products. Meanwhile, as the fossil fuel firms and the U.S. government argued that federal law preempts suits like Boulder’s since this issue is one of national and international significance, the Environmental Protection Agency has also recently said the Clean Air Act does not authorize it to regulate greenhouse gas emissions from cars or trucks.

Justice Department lawyer Sarah Harris argued during the proceedings that even as the EPA said it does not have the authority, cases like Boulders are still preempted under federal law, backing the oil companies’ position.

“Let's just hypothesize EPA is correct about greenhouse gases and its capacity to regulate them … let's say Congress decided ‘we're going to carve that out from EPA's responsibility.’ Does that mean that there couldn't ever be a federal common law cause of action for it just because Congress didn't grant it to EPA?”Gorsuch asked the government lawyer. Harris responded affirmatively, saying, “You're talking about a federal area where if Congress has not authorized it there's reason to think that federal common law shouldn't step in and fill the gaps.”

“So before the Clean Air Act, you'd have some federal common law cause of action to decide, but because of the Clean Air Act and Congress not addressing this issue, nobody can sue at all?”Gorsuch questioned.