The U.S. Supreme Court is scheduled to hear a landmark lawsuit next month in which oil and gas companies argue that state courts cannot decide who pays for damages caused by climate change. 

The court’s decision, expected before next summer, could set a precedent for dozens of similar climate accountability lawsuits around the country. 

“This is a historic moment where our home is going to be presenting these issues to the United States Supreme Court,” said Chris Winter, an environmental attorney and executive director of the Getches-Wilkinson Center at Colorado Law. “Here in Colorado, we are experiencing the effects of climate change firsthand. This is a case that’s happening in our backyard.”

On Oct. 5, the court will hear arguments on a petition filed by Exxon Mobil and Suncor, a Canadian oil giant. The city and county of Boulder are suing the companies, alleging that they knowingly concealed the environmental dangers of their activities, and that their actions contributed to a shifted climate that made wildfires, droughts and floods worse. 

After the Colorado Supreme Court allowed Boulder to advance the case in the state legal system last year, Suncor and Exxon Mobil brought the case to federal court. The companies argue that climate change is a national and international issue, and federal law preempts, or overrides, state law on the issue.

“What the Supreme Court will decide is not whether the oil industry is ultimately responsible for climate change, or if they were deceptive in their marketing practices. Instead, they will decide whether state courts are properly equipped to play a role in deciding how we allocate the costs of responding to climate change,” Winter said. 

The Boulder case is one of about three dozen lawsuits filed by state, local and tribal governments across the U.S. seeking to hold the oil and gas industry liable for climate change. None of them has progressed to trial yet. 

The Supreme Court has previously declined to hear similar petitions. It took up the Boulder case as the administration doubled down on efforts to shut down other climate accountability lawsuits nationwide. 

Last year, the U.S. Department of Justice preemptively sued the states of Michigan and Hawaii to prevent them from suing oil companies. Federal judges have dismissed both cases. 

CU Boulder Today sat down with Winter to talk about the Boulder case and the ruling’s potential implications. 

What does the petition by Exxon Mobil and Suncor argue? 

The oil and gas companies argue that whether they’re responsible for climate change damage is an issue that should be decided by federal law or Congress, and that federal law pre-empts state authorities. The companies believe the federal Supreme Court can step in and basically kill the case before it's able to go back to the state trial court.  

Why does Exxon Mobil and Suncor want the case before the Supreme Court?

The core of their argument is that state law has been pre-empted by federal law, and they are therefore asking the Supreme Court of the United States to kill the case. 

But the industry’s broader strategy is to avoid liability for causing climate change and to protect its financial interest in continuing to produce fossil fuels. Congress, our law-making body, hasn’t enacted a comprehensive climate change law. Thus, if federal law pre-empts state law, but Congress hasn’t implemented effective climate laws at the federal level, we could end up in a situation of not having any meaningful climate policy.   

Could the Supreme Court establish a precedent for similar cases in the country?

Possibly. But there is another possibility. The oil industry is asking the Supreme Court to step into the case very early, before there’s been any trial or rulings on the merits by the state court. This is an unusual ask.

So, it’s possible that the Supreme Court may send the case back to the state courts and ask them to do more work before the federal courts can review it. In that case, we will be left without a clear answer on the question of preemption. 

Have other climate lawsuits moved forward in other jurisdictions?

There has been extensive climate litigation in the United States and around the world, and some of those cases have moved forward.

For example, in the case of Held v. Montana, a group of young people successfully sued the State of Montana under the Montana Constitution for failing to protect their right to a clean and healthful environment. After an extensive trial on the merits, the trial court ruled in favor of the youth, which was upheld on appeal by the Montana Supreme Court in 2024.  

There are also examples from other countries around the world. In, KlimaSeniorinnen Schweiz, or the Senior Women for Climate Protection, an advocacy group in Switzerland, sued the Swiss government for insufficient action to curb climate change, leading to extreme weather that threatened their health. In 2024, the European Court of Human Rights ruled that Switzerland’s inaction violated human rights. 

In this case, the U.S. Supreme Court won’t be looking to those other examples as precedent. The Boulder case involves allegations of fraud and deceptive business practices under state tort law, which is a unique legal theory. 

What does Boulder hope to accomplish by progressing this case?

Local municipalities are spending a lot of public money to take care of their citizens, to protect infrastructure, and to protect local economies in the face of increased drought, fires, floods, and heatwaves. Boulder wants the oil industry, which profited from the marketing and sale of fossil fuels, to share in those costs. 

Congress has failed to pass meaningful climate legislation at the federal level. Boulder’s case is critically important, because without action by the courts, the costs of climate change will be imposed on all of us, and the oil industry will not have a sufficient financial incentive to protect the climate. 

To hold the oil companies accountable, Boulder hopes to get to a trial where the science of climate change and the evidence of the oil industry's deceptive practices, can all be put before a jury. Then we can have a determination in a court of law on whether those activities are causing climate change and causing harms.  

Beyond the preemption question, what is at stake in this case?

Climate change is hurting people in Colorado and across the country, and those effects are accelerating. Fundamentally, we’re trying to get an answer to this bigger question of who is going to pay for the enormous costs of adapting to climate change?

What Boulder is asking is that we need some monetary help from the oil industry to adapt to the effects of climate change, because the oil industry caused the problem, knew it was causing the problem, intentionally deceived consumers about it and then profited to the tune of trillions of dollars.

What are the broader implications of this case?

This case will potentially say something about the Supreme Court. If the Supreme Court takes an aggressive stance in support of the oil industry, it will indicate something troubling about how the Supreme Court is thinking about its role in our constitutional system. The Supreme Court has long upheld the role of states to protect their citizens from wrongful corporate behavior. If the Supreme Court sacrifices this bedrock constitutional principle to serve the ends of the oil industry in this case, we should be very concerned about corporate influence over the rule of law.