Colorado Supreme Court considers whether Boulder’s climate lawsuit against Exxon and Suncor can proceed

Colorado’s supreme court heard arguments Tuesday in Boulder County’s legal efforts to hold Exxon Mobil and Suncor Energy accountable for allegedly misleading the public about the threats presented by climate change. 

The case – first filed in 2018 – seeks damages from the companies to pay for the costs of natural disasters like floods and wildfires, which have grown more severe and frequent due to global warming.

Today’s oral argument focused on a narrow question with big implications: whether Boulder’s district court incorrectly allowed the county’s lawsuit to proceed under state law. 

For years, Exxon Mobil and Suncor have tried to move the proceedings to federal court or dismiss it outright, according to court documents and today’s arguments.

“We think Congress would have to authorize the state to permit this,” said Kannon Shanmugam, an attorney for Exxon Mobil. 

So far, that strategy has proved unsuccessful. In 2023, after several hearings in federal court, the U.S. Supreme Court declined to hear a challenge to the case. In June, the Boulder District Court denied further motions to dismiss the case. If the state supreme court upholds that ruling, it would clear the way for the beginning stages of a trial pending any further legal challenges.

“Boulder is increasingly burdened by the impacts of an altered climate, and our community cannot keep bearing the costs alone while those responsible avoid paying their fair share,” said City of Boulder City Manager Nuria Rivera-Vandermyde in a June statement.

Colorado has experienced an increase in billion-dollar weather disasters since 1980. Researchers say climate change has at least worsened some of those disasters. In 2021, the Marshall Fire ripped through Boulder County, destroying over 1,000 homes and causing more than $2 billion in property damage.

The lawsuit filed by Boulder County and the City of Boulder argues the fossil fuel companies spent decades misleading Colorado consumers about the potential risks of consuming their products. It uses a similar legal strategy as cases filed against the tobacco industry, which forced companies to help people dealing with health problems caused by smoking cigarettes. 

Climate change, however, is a far broader problem fueled by tailpipes and smokestacks worldwide. Due to that reality, the Colorado Supreme Court is currently considering whether climate-warming pollution is inherently an issue of federal concern and should not be addressed by state courts. 

On Tuesday, Shanmugam, the attorney representing Exxon Mobil, argued allowing the case to proceed risked usurping the federal government's authority to regulate pollution that crosses state lines. If every local government filed a similar suit, he asserted, it would effectively displace the federal government’s ability to regulate air quality and conduct international affairs. 

Meanwhile, Marco Simon, an attorney for the local governments, argued it doesn’t matter if the emissions occurred outside of Colorado. Since the damages are taking place within the state’s boundaries, Colorado residents deserve financial compensation. 

“No constitutional text or federal statute would allow a Texas or Delaware corporation the unlimited right to cause injury to communities within the state of Colorado without paying for their share of the damage caused. Exxon is here asking you to create an immunity Congress has not provided,” Simon said. 

The case is similar to dozens filed by municipalities nationwide seeking some compensation from fossil fuel corporations to pay for the effects of climate change. Many of those cases remain mired in legal hold ups. Others are slowly working their way through the courts.

Boulder’s case may have gotten a boost recently from developments in a similar case in Hawaii. In 2023, the Hawaii Supreme Court allowed a Honolulu lawsuit against oil giants including Sunoco and Shell to go to trial. The suit alleges that those companies deliberately concealed how burning fossil fuels contributes to climate change. 

In January, the U.S. Supreme Court declined to hear challenges to that case, paving the way for it to remain in state court. 

That outcome is a “significant milestone” according to Marco Simons, an attorney representing Boulder County, the City of Boulder and San Miguel County in their suits against the energy companies.

But other cases have not survived legal challenges. In January, a New York state supreme court justice dismissed a case filed by New York City against fossil fuel companies, which alleged they misled the public about climate change. 

A decision in the Boulder case is expected in several months.