Whipping through the county, averaging 50 to 60 mph, gusts that day peaked at 115 mph. “That alone probably would have been a noteworthy event,” said Lauren McIntire, a software engineer who was living in Louisville, Colorado, a town in the southeast portion of Boulder County. Her morning had started like any other: She took her dog Catalpa (Cat for short) for a walk around the neighborhood, which appeared unusually dry. There had been no new snow or precipitation for almost a week, and the totals for that December were far below normal, according to data from the National Weather Service. Indeed, the second half of that year had been especially dry, the second hottest ever recorded.

McIntire and Cat were back home by 9 a.m. so McIntire could get online for work. She had just started a new job and was eager to make a good impression. McIntire had the house to herself as Alex Zdereic, her partner and a graduate student at the University of Colorado, Boulder’s astrophysics program, was around the corner working at a coffee shop.

By midmorning, the winds grew more intense. McIntire saw “shingling coming off of houses and poster boards from businesses flying through the neighborhood.” Just before noon, she received a text from her neighbor with an image of a towering plume of smoke in Boulder County, captioned “fire just started in south boulder.” Colorado endures about 2,500 wildfires a year, and it was a busy day, so McIntire brushed off the blaze. But an hour later, Zdereic came home and said it was smokey by the coffee shop a block away, and when McIntire looked outside, she saw “a bunch of smoke coming towards us.”

The two could hear firetrucks moving about the neighborhood and decided it would be safest to
evacuate. They put on mountain bike goggles so they could see through the smoke as they ferried their animals (the couple also has a gecko, named Cuppy, and some fish) and a few other belongings from their home to their car. They had just invested in an inflatable boat for their summer rafting excursions but did not have room for it in their vehicle. They managed to negotiate with a neighbor for him to take their raft. As they stood outside, “it was raining ash and the wind was blowing ash in our faces,” McIntire said. “After that we felt really urgently that we had to leave.”

By now, the fire had enveloped their neighborhood. McIntire and Zdereic navigated around the burning road leading to their apartment complex and made their way to downtown Louisville, thinking it might be safer there. But it was “a ghost town,” McIntire said, with lines of cars trying to evacuate. They got hold of a friend in nearby Longmont and arranged to stay there. Three days later, they returned home.

“It was weird to go back,” McIntire said. As she and Zdereic walked around the remnants of their neighborhood, McIntire saw burned pages strewn across the charred streets. She bent down and grabbed a few. One looked like the remains of a Playboy magazine, the other two belonged to books, perhaps.

“It felt encompassing of what you would find in someone’s home,” she said. Though they did not lose their home, the couple felt it would be unhealthy to stay in Louisville. When they returned to their apartment, they found “a half inch of ash on our patio and front door,” said McIntire, which she suspected made its way into their apartment, too. Four months after the fire, they moved about 9 miles north to Gunbarrel.

McIntire and Zdereic were, in a warped sense, lucky. They did not lose their home to what would come to be known as the Marshall Fire, the most destructive wildfire event in Colorado’s history and likely the most destructive event of any kind in Boulder County’s, according to an investigative summary authored by the County Sheriff’s Office, and its district attorney. The fire had claimed the lives of two people, destroyed over 1,000 homes and commercial properties and burned nearly 6,000 acres of land. Almost a year after the blaze, Colorado’s insurance commissioner said the final damages tally exceeded $2 billion.

Eight days after the Marshall Fire, U.S. President Joe Biden toured the wreckage and gave a speech to the community, saying, “We can’t ignore the reality that these fires are being supercharged. They’re being supercharged by a change in the weather.”

Three years before the Marshall Fire, Boulder and San Miguel counties had filed a lawsuit seeking damages from the oil companies Exxon and Suncor by claiming much the same thing. Changes in the climate — driven, at least in part, by the burning of Exxon and Suncor’s fossil fuels — have harmed their citizens and damaged their infrastructure, economies and natural environment, entitling them to compensation from the oil companies for those damages, the two counties claim.

Together, Boulder and San Miguel are part of a small but growing number of cities, states and counties seeking to hold fossil fuel companies responsible for damages allegedly caused by their emissions or for allegedly misleading consumers about their product’s impact on the environment. Some involve densely populated urban areas like New York City and San Francisco. Others are taking place in some of the smallest and most idyllic regions in the U.S., like Boulder and Maui in Hawaii, which was devastated by a historic and unprecedented wildfire in August.

For years, many of these suits have bounced between state and federal courts as fossil fuel companies seek more favorable rulings in the latter. But recent rulings from the Supreme Court and a handful of state courts have appeared to settle the question of jurisdiction, upholding the plaintiffs’ argument that their cases should be heard in state courts. And now, after members of the United Nations included language about transitioning the global energy system away from fossil fuels at the conclusion of COP28, these cases take on new stakes. If the plaintiffs are successful, environmental law experts say these cases may establish a legal precedent that could drastically alter an oil company’s cost of doing business, as a loss in just one case could cost a company billions. A victory could also serve as the basis for a nationwide settlement, or spark a wave of similar litigation across the U.S. Even one of those outcomes would be unprecedented, but given the similarities of the claims being made in each case, it may take only one favorable ruling to trigger an avalanche of similar litigation worldwide.

In September 2005, a month after Hurricane Katrina tore through much of the U.S. Gulf Coast, a group of property owners in Mississippi sued insurance and fossil fuel companies, seeking compensation for damages from the storm. In their filing, the plaintiffs wrote: “The environmental conditions present in the Gulf of Mexico which fostered the strengthening of Hurricane Katrina are a direct result of a condition sometimes described as ‘Global Warming,’” which they said is “caused by a depletion of protective ozone and a build-up of greenhouse gasses, including, but not limited to, carbon dioxide all of which is a byproduct of the oil refining and production.” They named multinational corporations Chevron, Exxon and Shell as defendants, among others.

The case, Comer v. Murphy Oil USA Inc., fared poorly. Two years after the group filed, a judge granted the fossil fuel companies’ motion to dismiss, citing a “lack of standing” in the original claim, meaning the court did not think there was solid legal ground for the defendants to claiM injury from an oil company’s behavior.

As the appeals in the Comer case were making their way through the courts (all were unsuccessful), a similar federal suit was filed by the Native Village of Kivalina, located roughly 70 miles north of the Arctic Circle on a narrow, 6-mile-long barrier reef island along Alaska’s northwestern coast. Kivalina, populated by about 400 Inupiat Eskimo whose ancestors had lived on the land since “time immemorial,” they wrote, sued Exxon, BP America, Shell, ConocoPhillips, Chevron and other energy and utility companies for damages to their disappearing community. Their critical infrastructure faced permanent destruction, they argued, and their “houses and buildings are in imminent danger of falling into the sea as the village is battered by storms and its ground crumbles from underneath it.”

The only option left to the community, one endorsed by the U.S. Army Corps of Engineers, was to move the village. “If the entire village is not relocated soon, the village will be destroyed,” the agency wrote. (Residents of Kivalina are still living on the barrier reef, and progress to move off the island is halting.)

The village filed its case in a district court in California for its approximate physical presence to Kivalina. As with Comer v. Murphy, the court granted the oil companies’ motion to dismiss, in part because Kivalina’s claim was “dependent on a series of events far removed both in space and time from the Defendants’ alleged discharge of greenhouse gasses,” the judge wrote.

The judge, Saundra Brown Armstrong, appointed in 1991 by President George H.W. Bush, a Republican, also felt it would be inappropriate to rule in a case that “by definition, entails a determination of what would have been an acceptable limit on the level of greenhouse gasses emitted by Defendants.” Kivalina, she argued, was asking her “to make a policy decision about who should bear the cost of global warming.” The village’s appeal was rejected, and in its reasoning, the 9th Circuit Court of Appeals added that the Clean Air Act displaced Kivalina’s claims because it made the government responsible for setting and regulating emission standards, not a court. Kivalina again sought an appeal, this time from the Supreme Court, which declined to review the case.

Though both were unsuccessful, the two cases are part of a previous wave of litigation that helped establish the contours of contemporary suits for damages from fossil fuel companies, said Korey Silverman-Roati, a senior fellow at Columbia University’s Sabin Center for Climate Change Law. The legal precedent saying the Clean Air Act displaces a federal common law claim, for instance, is part of the reason oil companies have worked hard to have these suits moved to federal courts.

“The fossil fuel companies want to argue that these plaintiffs are trying to regulate the climate system,” explained Silverman-Roati, who studies these cases using a database made by the Sabin Center. In this latest wave of litigation, however, “almost unanimously, courts have rejected those arguments,” he said, though he added that it’s possible fossil fuel companies rehash those arguments in a motion to dismiss. This April, the Supreme Court weighed in on the question of federal versus state jurisdiction, ruling in favor of five cities and the state of Rhode Island by sending their cases back to state courts for further litigation, potentially answering the question of jurisdiction in the remaining similar cases.

That decision from the Supreme Court came as “a little bit of a surprise” to Mark Squillace, a natural resources law professor at the University of Colorado, Boulder, given the court’s conservative makeup. I met Squillace at his office on campus around noon on a blistering 95-degree day in late July to talk about Boulder’s claim. Squillace greeted me in his spacious, air-conditioned room on the fourth floor of the law building, surrounded by freshly manicured grass and a beach volleyball court. A large window offered a view of the ridge line leading to the Flatirons, just a few miles west of where we sat, and behind his desk (which he had converted from standing to sitting with the push of a button as I entered) hung a poster of a map of Colorado. He pointed to Allenspark, a mountain town about 8,500 feet above sea level where he and his wife own another home. “It’s days like today I wish I was over there,” he said.

Squillace began by explaining the particulars of suing for damages.

“In court, if you want damages, you have to show causation,” he said. “Showing that causal link between the emissions from the fossil fuel companies and the injuries that occur can be challenging.” Emissions are not confined to the states they originate in; once they’re airborne, they could go anywhere — and their effects can be difficult to predict. “What the cities are counting on, and the states that are suing are counting on, is that there is enough evidence that climate change has had an appreciable impact on injuries that they’ve suffered,” he said.

That evidence will look different for every city and state given the diversity of climates across the U.S. Since the turn of the century, only a handful of cases across the country have attempted to draw a line from oil companies’ emissions to a long list of adverse climate affects, mainly occurring in areas of the country near the ocean.

In Boulder County, which is landlocked, the threat of climate change is different but no less potentially destructive. Colorado’s communities are experiencing “increases in extreme hot summer days and minimum nighttime temperatures, precipitation changes, larger and more frequent wildfires, increased concentrations of ground-level ozone, higher transmission of viruses and disease from insects, altered stream-flows, bark beetle outbreaks, ecosystem damage, forest die-off, reduced snowpack, and drought,” said Boulder and San Miguel in their official complaint. Colorado’s economy is affected too, they argued.

“The state’s $41 billion agriculture industry is imperiled by rising temperatures and drought, while the $5 billion ski industry is in jeopardy as a result of ‘low-snow’ winters and shorter seasons.”

Squillace expects the plaintiffs’ lawyers to point to the Marshall Fire as further evidence of the cost of climate change.

“When you have to fight a fire, you have local costs of engineering the recovery efforts and the fire suppression efforts,” Squillace explained. He said Exxon and Sunoco will most likely argue “what they call a failure to state a claim,” the equivalent of saying “maybe you’re injured, but you haven’t proven it’s us,” he said.

While the two counties’ claims may be unique given their geography, they share one trait with every other place suing oil companies for climate damages.

“It’s pretty clear that the blue states are most concerned about climate change and a lot of the red states are actively promoting fossil fuels,” Squillace said. California, long regarded one of the most liberal states in the U.S., leads the way nationally in active litigation against fossil fuel companies. In addition to its liberal reputation, California boasts snow-capped mountains, desert landscapes and several of its largest cities are located near the ocean, meaning its citizens face an array of potential problems caused by climate change.

Dan Farber, co-director of the Center for Law, Energy & the Environment at the University of California, Berkeley, expects damages from droughts and wildfires to be the focus of several Californian cities suing fossil fuel companies. “There have been times where there have been warnings that it’s unsafe to go outdoors,” he said, pointing out that the state was in the midst of a heat wave that July. Sea level rise could come to bear on the proceedings, too, he said. “We’re getting close to where outlet pipes could end up under water and therefore not work and cost a lot of money to fix.”

This is precisely what San Francisco and Oakland claim in their suits against fossil fuel companies, which ask a judge to compel five oil companies — BP, Chevron, ConocoPhillips, Exxon and Shell — to pay for climate adaptation projects. In order to deal with rising sea levels and increased risk of flooding, San Francisco is planning to fortify over 3 miles of sea wall along its coast, a project the city expects will cost over half a billion dollars in the short term. “Long-term upgrades to the seawall are projected to cost $5 billion,” the city wrote in its 2017 filing. Its stormwater and port infrastructure could use an upgrade, too, they said, putting the total cost for all necessary climate adaptation projects at “billions of dollars.”

In Oakland, the problems are much the same. The city wrote that it had identified upgrades to its sewer and stormwater infrastructure, protecting its low-lying airport and “armoring Oakland’s coast” as its most urgent needs. “Oakland has already begun to feel injury from sea level rise,” they wrote, but “its most severe injuries by far are the injuries that will occur in the future if prompt action is not taken to protect Oakland and its residents from rising sea levels caused by global warming.” The city estimated it would take billions of dollars to fund its climate adaptation projects.

Farber expects that fossil fuel companies will argue that San Francisco and Oakland would need to make infrastructure upgrades regardless of climate change, but persuading a judge to dismiss these cases on those grounds may be harder to accomplish in state court. “Getting these cases back to state court is a really important step,” he said. “I think they’ve got a much fairer shot at making their case in state courts.”

Smoke from wildfires in Canada blanketed much of the Northeast and parts of the Midwest this past summer; the Fourth of July was the hottest day in Earth’s history, according to measurements from the Climate Change Center at the University of Maine — the average temperature across the globe was 69.92 degrees Fahrenheit — a distinction it held for a day before being equaled on July 5, then surpassed on July 6. For 31 consecutive days across June and July, the National Weather Service recorded temperatures in Phoenix, Arizona, at or above 110 degrees Fahrenheit, breaking a record. The record-hot summer has turned into a record-hot year, the hottest ever recorded by humans, scientists say. Farber, Silverman-Roati and Squillace expect that proving a link between emissions from fossil fuel companies and damages from extreme climate events will be a complex and difficult process for each of the 26 active suits. As Farber put it, despite the recent Supreme Court decision favoring plaintiffs, “it’s not by any means a sure thing that state courts would be inclined to rule in their favor.”

But that task may not be insurmountable. “In the interim since Hurricane Katrina, the science around climate attribution has gotten significantly better,” Silverman-Roati said. “Scientists are able to tell us with much more certainty that an individual climatic event is a result of climate change.” With wildfires, for example, government reports, independent studies and scientific modeling have all shown that anthropogenic activity has played a role in increasing the duration and frequency of fire seasons across the Western United States. This August, after a wildfire devastated much of Maui County, claiming the lives of more than 100 people, climate scientists told The New York Times that an increasingly dry climate and decreasing cloud cover and precipitation helped spur that fire’s devastation.

Even if climate modeling is more accurate, it is not every day that multibillion-dollar, multinational companies are held accountable for alleged damages to the public. Yet precedent may exist. Farber pointed to the cases against big tobacco and opioid companies, each of which yielded billions of dollars in legal settlements, as examples of powerful companies being forced to settle claims that their product caused the public harm and cost local governments money. “In both of those previous cases, it turns out that there was not at all good faith” behavior exhibited by the companies, said Farber. Tobacco companies, for instance, “knew perfectly well that cigarettes cause cancer while they were still engaging in this huge campaign to confuse the issue,” he said. “There’s certainly at least evidence for some of the oil companies that something similar was true here.”

Farber was referring to reporting and research that has emerged in the last decade that demonstrates at least some oil companies were aware of their product’s effect on the climate. A nine-part series by Inside Climate News, published in 2015, used internal company documents, interviews with former employees and archival research to demonstrate that Exxon had been aware of climate change as early as 1977 and conducted research on the subject for almost a decade. In 1982, M.B. Glaser, Exxon’s head of environmental affairs, distributed a memo to Exxon management on the “greenhouse effect,” explaining the burgeoning scientific understanding that fossil fuel combustion was increasing atmospheric carbon dioxide (CO2) levels — and warming the planet. Parts of the memo now appear eerily prescient. Glaser predicted that global warming wouldn’t be detected until the mid-1990s at the earliest and that changes in the environment could include increased droughts, flooding and sea level rise from melting arctic ice sheets. Mitigating rising temperatures would require a “major reduction in fossil fuel combustion,” he wrote. It wasn’t all doom and gloom; Glaser pointed out there was no “unambiguous scientific evidence that the earth is warming,” and given that uncertainty, “making significant changes in energy consumption patterns now to deal with this potential problem” would have been “premature in view of the severe impact such moves could have on the world’s economies and societies.”

A few years after Inside Climate News’ story broke, a reporter at Dutch news website De Correspondent unearthed a 1988 report by Shell titled, “The Greenhouse Effect,” in which the company observed that burning fossil fuels and deforestation were the main contributors to rising levels of CO2 concentration, which could create “fast and dramatic” changes in the climate. If current trends held, they wrote, concentrations of CO2 in the atmosphere would double by the third quarter of the 21st century, which computer modeling predicted would result in an increase in global mean temperatures of between 2.3 and 5.9 degrees Fahrenheit.

“The likely time scale of possible change does not necessitate immediate remedial action,” the memo’s authors wrote.

Were the predictions by scientists at oil companies — who had been modeling climate change decades before the public knew about it — any good? That’s the question researchers from Harvard and the Potsdam Institute for Climate Impact Research in Germany set out to answer in a report published in January in Science. They compared the projections and models from Exxon’s scientists with observed temperature changes since the reports were generated from 1977 to 2002, and found that Exxon’s results were “consistent with, and at least as skillful as” independent and government models; the company accurately predicted when climate change would be discovered and the importance of holding the world’s warming below 3.6 degrees Fahrenheit.

“On each of these points, however, the company’s public statements about climate science contradicted its own scientific data,” the authors concluded.

BP, Chevron, Citgo, ConocoPhillips, Marathon Oil, Phillips 66 and Shell did not return requests for comment for this story. Lawyers representing Exxon and Suncor in the Boulder and San Miguel case declined to comment.

To leverage the body of documentation alleging oil companies tried to hide their product’s effect on the climate, plaintiffs will have to “pin down what the companies knew and when they knew it as best they can,” Squillace said. That process will take place in “discovery,” a legal term for the pretrial process during which plaintiffs and defendants receive access to each side’s internal records and documents. Barring a protective order, findings can be made public. Only once discovery is complete, which Squillace said could take years, can a case go to trial.

And, once a verdict is reached, a victory in one case, however improbable, could influence whether other cities and states across the country choose to file similar cases. “There’s an element here where success in these cases will lead to more suits,” Silverman-Roati said. “It can be persuasive for a judge in one state to see what another state does.”

Persuasive, but not binding. “What one trial judge says isn’t a precedent that another trial court has to follow,” Farber said. “But I think psychologically it matters,” he continued, “if they win one, I think that will encourage additional suits, and probably not just in the U.S.”

Almost two months after the Supreme Court decision, Multnomah County in Oregon, home to the city of Portland, filed a claim against Exxon and other fossil fuel companies seeking damages from a heat dome that engulfed the county in 2021. In their filing, they called the heat dome “the hottest event in the region since the beginning of the record time,” which they put at 950 CE.

At their new home in Gunbarrel, Colorado, where the couple moved in the spring of 2022, McIntire and Zdereic have rebuilt their life since the Marshall Fire. This April, the two got married, and a few months later they went rafting down the Yampa River in Northwest Colorado (their dream is to traverse the Grand Canyon by raft). McIntire is learning Japanese for their honeymoon to Japan this January. They still take Cat for a walk around the neighborhood most mornings.

Looking back at the events of Dec. 30, 2021, fills McIntire with a range of emotions. On the one hand, “even now I find it hard to say I’m a victim of a fire,” she said, before adding, “maybe it’s survivor’s guilt.” Still, the fire has “reframed how I think about things,” she said. “I feel like I’d have a hard time living next to an open space now, because that’s how fires spread.” In March 2022, there was another, less severe fire in Boulder County. No one was injured and no structures burned, although several thousand people were told to evacuate their homes.

“I feel like I’m kind of hardened” to the fires, said McIntire. “This happens now; this is just normal.”

McIntire had not heard about the lawsuits against oil companies and did not feel too optimistic about their chances of success. She said she feels like “there’s never any accountability and things never change” when dealing with large and powerful companies. Still, she thinks it’s worth a shot.

“I’m glad about it,” she said. “It’s a starting point, but there needs to be a lot more done. It’s bigger than Boulder and bigger than Colorado.”

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