After nine hours of debate, a state Senate committee on March 28 voted down a groundbreaking and controversial plan to combat global warming by winding down new oil and gas drilling in Colorado.

The outcome wasn’t surprising for state Sen. Kevin Priola, D-Henderson, one of the bill’s top supporters. After working as a lawmaker for around 15 years, Priola knew the policy was a long shot. He sponsored it anyway to force a larger debate about Colorado’s current climate strategy.

“To my knowledge, this is the first time we’ve had a proposal in Colorado to phase out fossil fuels on a timeline,” Priola said, adding that bills often succeed only after years and years of attempts.

By running the legislation, Priola and co-sponsor state Sen. Sonya Jaquez Lewis, D-Longmont, proved that Colorado lawmakers likely won’t embrace the approach in the immediate future. The proposal met sharp opposition from the state’s oil and gas industry, which argued that it would have killed jobs and cut off essential funding for schools and other public programs.

The plan also lacked support from within the Democratic Party. In a recent planning document, Gov. Jared Polis’ administration noted it opposed any plans to limit oil and gas development since it could increase energy costs. In the end, two Democratic state senators joined Republicans to defeat the bill in its first committee vote.

But the recent legislative fight also marks the latest chapter in Priola’s political evolution from a pro-business Republican into one of the state’s leading climate hawks. Unable to run for reelection — Priola is term-limited in 2025 — the state Capitol veteran has embraced a recent shift among some of the world’s top climate scientists and advocates, who have increasingly called for bans and other policies to prevent further fossil fuel extraction.

Priola hopes his political journey will offer clarity to future policymakers — and lead them to reignite the fight in future legislative sessions.

Priola grew up in Henderson, a community in Adams County where he still lives with his wife and daughters. While it’s since mostly evolved into a Denver suburb, Priola said it was once more of a middle-class region with deep agricultural roots. That includes his family, which grew flowers in a commercial greenhouse along the Platte River.

At 17, Priola registered with the Republican Party due to its fiscal conservatism and tough stance against the Soviet Union. He also gained a keen awareness of the relationship between plants and climate conditions by working in the family greenhouses. If the temperatures climbed by just a few degrees in the summer, Priola remembers seeing the flowers darken to retain moisture.

“You could see the stress on the plant,” he said. “That really stuck with me.”

Priola remembers learning about climate change in middle school and high school in the early 1990s but assumed the planet likely wouldn’t become an overheated greenhouse within his lifetime.

That view slowly changed as Priola noticed subtle shifts in Colorado’s natural environment. He heard local farmers had extended their growing seasons as frost arrived earlier in the spring and later in the fall. An avid skier, he also felt slushier conditions that seemed to arrive in February rather than later in March.

Priola said all those observations clicked into place during a snowstorm in January 2015, seven years after he first won a seat in the Colorado House. He remembers looking out of his garage door and noticing large, puffy flakes hitting his driveway. It struck him as the sort of precipitation Colorado experiences in the spring, not the dead of winter.

“I realized that this is happening now, and policies need to be put in place because we can’t wait any longer,” Priola said.

Priola soon bought a Tesla and plastered his roof with solar panels. At the same time, he established a reputation as the lone Republican sponsor of many environmental and clean energy bills, including legislation to promote recycling and electric cars.

Those environmental and climate politics put him increasingly out of step with his Republican colleagues, but Priola maintained his support for gun rights and opposed efforts to expand abortion access.

The strain, however, reached a breaking point in the summer of 2022. Priola announced his decision to leave the Republican Party and become a Democrat, citing his former party’s ongoing efforts to discredit the 2020 election results and its unwillingness to address climate change.

“The Republican Party I joined decades ago created national parks, preserved federal lands and protected wildlife,” he wrote in a letter explaining the decision. “Today, my Republican colleagues would rather deny the existence of human-caused climate change than take action.”

While Priola’s views on climate change came into focus, he wasn’t always aligned with environmental groups trying to reign in the state’s oil and gas industry

In 2019, for example, he voted against Senate Bill 181, legislation that tightened Colorado’s oil and gas regulations and gave more power over new drilling to local communities.

While the fossil fuel industry mounted an all-out campaign against the proposal, Priola said he opposed it due to fears the legislation would add unnecessary bureaucracy and fail to cut local air pollution. It ended up winning approval without his support.

Priola has only grown more concerned about local air quality since then.

After a bout with pneumonia around two years ago, Priola found himself coughing and sneezing more often than usual, which is why he now always keeps a handkerchief in his pocket. Those respiratory episodes also appear to occur whenever local air quality declines due to wildfire smoke or high ozone levels, Priola says.

During the legislative offseason in 2023, Priola learned that oil and gas operations are the largest local source of smog-forming ingredients along the Front Range. He also followed the deliberations at COP 28, the United Nations’ international climate summit that ended with an agreement among nations to “transition away from fossil fuels” to avoid the worst consequences of global warming.

Priola said both events led him to sponsor the failed phase-out legislation — plus another pending bill to ban drilling and hydraulic fracturing during the summer ozone season.

Those proposals have been noticed in Priola’s district, which stretches from Adams County into Weld County, the epicenter of Colorado’s oil industry.

Scott Bright, a Platteville Republican who owns a chain of child care centers in the area, is now running for the Senate seat, which is widely seen as one of his party’s best chances to claw back some ground in the Colorado Legislature. In an interview, Bright said residents are hungry for a lawmaker who supports the industry.

“They’re like, ‘We’re so glad to be rid of that turncoat,” Bright said. “The constituency here in Weld County is so disappointed in the direction he’s taken on their livelihoods.”

Priola, meanwhile, sees his political transformation as a byproduct of his values and resistance to conform to either party. His views on climate change pushed him out of step with Republicans earlier in his career. In his new role as a Democrat, he said the tendency has led him further to the left than his colleagues on environmental issues, but he remains committed to his identity as a pro-life Catholic.

“I don't know what's more pro-life than protecting the planet for all of its inhabitants,” Priola said.

To read more stories from Colorado Public Radio, visit www.cpr.org.