The Colorado House debated and then postponed more debate Monday on a statewide climate action plan, the first step to reducing greenhouse gas emissions.
Republicans ran an hours-long string of failed amendments to soften the liberal blow of House Bill 1261, which Speaker KC Becker of Boulder has called one of her highest priorities this session.
The bill aims to reduce greenhouse gas emissions by 26 percent by 2025 and 50 percent by 2030, based on 2005 levels.
"We talked about how California has done something very, very similar," said Rep. Tim Geitner, R-Falcon. "Here we are. We're back to California again."
The legislation intends to keep Colorado on track to meet greenhouse gas reductions goals on par with the 2015 Paris climate accord. President Donald Trump pulled the nation out of that international agreement in 2017.
"I believe climate change is one of the defining challenges of our time," Becker said on the floor Monday morning.
"States must act proactively, quickly and comprehensively to deal with climate change. This bill is just the first stroke to the state of Colorado addressing its obligation to bring down the amount of carbon we're emitting into the air."
Under the measure, Colorado would aim to trim emissions from sources such as transportation, electricity generation and oil and gas operations.
"Here in Colorado, we're proud we tackle environmental challenges head-on," Becker said.
She said her bill "simply sets goals." The state's Air Quality Control Commission would set rules to help achieve those goals.
The bill calls for tracking sources when communities appear to be disproportionately affected by pollution. It also calls for coordination between air-quality regulators and the Colorado Public Utilities Commission.
If the legislation clears two votes in the House, which is likely, it still must pass the Senate -- where Democrats hold a narrower lead -- before the four-month session adjourns on May 3.