After one of the largest wildfires in state history devastated Rio Blanco County, Colorado in 2025, Deirdre Macnab saw her share of horrors across the community: cows burned to death, pigs died from sunstroke, and pastures were blanketed in thick black smoke. This past summer was no different. “It was hellish,” Macnab told me. “Between the temperature and the drought, 2026 was a dress rehearsal for what we know is coming.”

Over the last few years, Macnab, a regenerative cattle rancher, and her fellow ranchers have experienced the devastating effects of climate change on their livelihood. “Every single rancher can tell stories about how their operations have been impacted and in some cases ended,” she said. On Monday, their stories, along with dozens of others about the mounting climate costs in Colorado, will arrive at the US Supreme Court, which will hear oral arguments for the much anticipated case between Boulder, Colorado, and Suncor Energy and Exxon Mobil Corporation.

The case revolves around a dispute between the City and County of Boulder, which first sued the energy companies in 2018. They are arguing that Suncor and Exxon deceived the public about the dangers of climate change and should be forced to pay damages for climate-induced heat waves, wildfires, droughts, and floods. “The damages will only multiply as climate change worsens,” Boulder stated in its lawsuit. Suncor and Exxon, meanwhile, are asking the justices to kill the case before it makes it to trial—and with it a host of other state-level climate cases.

Depending on how the eight justices rule—Justice Samuel Alito announced what some considered to be an 11th hour recusal earlier this week—the case could have far-reaching consequences for people like Macnab, who submitted an amicus brief in support of Boulder along with six other ranchers. But its implications extend beyond the state’s borders: dozens of other climate-related lawsuits hang in the balance of how Suncor v. Boulder is decided. Indeed, experts say that its implications extend beyond climate to include other damages-related suits, from asbestos cases, to pharmaceuticals, to opioids.

The state of Colorado is estimated to pay $37 billion in climate damages by........

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