When Democratic lawmakers announced their oil and gas reform bill last month, they did so in front of a bank of TV cameras at a crowded press conference at the State Capitol, flanked by dozens of state and local officials, leaders in both the House and Senate, and Governor Jared Polis.

Just a few weeks later, Democrats have unveiled what is in many ways a more ambitious bill — a legislative prescription for the defining public policy challenge of the 21st century — in a short press release sent to reporters late Thursday, March 21.

House Bill 1261, introduced by Democrats in the legislature’s lower chamber, would formally set new goals for Colorado’s efforts to reduce greenhouse gas emissions, most notably a 50 percent cut in statewide emissions by 2030. It also directs air quality regulators to implement rules that will help the state meet the new goals.

“Climate change is real. It’s happening. And we have a moral and economic imperative to act now,” said House Speaker KC Becker, a Democrat from Boulder and one of the bill’s sponsors, in the statement announcing the legislation. “I cannot think of a more important challenge for our state to tackle than climate change.”

The bill’s modest roll out may be partially attributable to disagreement among top Democrats over how strongly the state should enforce its emissions goals. Becker and Polis have clashed over some of the bill’s key provisions, the Colorado Independent reported Wednesday, with the governor reluctant to impose robust mandates on emissions sources. The two reportedly reached an agreement on the bill’s contents earlier this week.

Colorado’s only current emissions goal was set by former Governor John Hickenlooper in a 2017 executive order, which committed the state to cutting carbon emissions 26 percent below 2005 levels by 2025. Becker’s climate bill would codify that target in statute, and add two more, a 50 percent cut by 2030 and a 90 percent cut by 2050.

That’s roughly in line with the timeline endorsed by the world’s top climate scientists in a landmark 2018 report by the U.N.'s Intergovernmental Panel on Climate Change. Stressing the need for “rapid, far-reaching and unprecedented changes in all aspects of society,” IPCC scientists warned policymakers that emissions must fall 45 percent by 2030 and reach net zero by 2050 or sooner. Though many other U.S. states have set near-term emissions targets in line with IPCC recommendations, they have been reluctant to commit to full carbon neutrality, and no state has yet pledged 100 percent decarbonization by any date.

In order to meet its goals, HB 1261 directs regulators at Colorado’s Air Quality Control Commission to develop rules aimed at reducing the emission of carbon dioxide, methane and other greenhouse gases — though it also specifies that in drafting these rules, the commission should take into consideration "the costs of compliance" and "the time necessary for compliance."

The bill also directs AQCC regulators to begin reporting the state’s progress toward its emissions goals every two years. Colorado currently reports its greenhouse gas inventory every five years; the last inventory was released in 2014, and the latest update is expected in the first half of this year.

The 2014 report estimated that statewide emissions totaled 123 million tons of carbon-dioxide equivalent in 2005, meaning that in order to meet the climate bill's goals, Colorado has less than eleven years to cut 68.5 million tons from its current emissions levels. To put the scale of that challenge in perspective, the pledge made last year by Xcel Energy, Colorado's largest electric utility, to cut emissions from electricity generation 80 percent by 2030 — by far the largest single emissions-reduction effort in Colorado history — would result in an overall reduction of less than 18 million tons.

If the bill passes, it will be the Polis administration's responsibility to close the gap by implementing new emissions rules across a wide variety of industries and pollution sources, from transit and buildings to agriculture and waste management.

"We're really looking to Governor Polis to be a leader on this effort," says Micah Parkin, executive director of climate activist group 350 Colorado, "and calling on him to make Colorado a national leader in the effort to address the climate crisis, in a timeframe that science and justice demands."