On October 20th, Colorado's Air Quality Control Commission voted to adopt the Colorado Clean Cars Rule, making Colorado the ninth state to adopt California's Advanced Clean Cars II program and the first in the Mountain West. The rule requires automakers to ramp up delivery of zero-emission vehicles (ZEVs) to Colorado through 2032, requiring 82% of new cars sold in the state to be ZEVs in that year.
The rule will accelerate Colorado's critical transition to clean vehicles and bring enormous health, climate, and economic benefits to the state. Colorado's Front Range is plagued with some of the nation's worst air quality and was recently downgraded to severe nonattainment for ozone by the U.S. EPA. The state is also off-track to hit its 2050 net-zero goal for transportation, but the new clean cars rule and a similar program for larger vehicles like trucks and buses adopted in April will help slash GHG emissions in the sector.
Sierra Club and its allies mounted a strong case for the Commission to push beyond the 2032 rule proposed by the Polis Administration and instead adopt California's full program, which requires 100% clean vehicle sales in 2035. While state regulators stopped short of a 100% rule, our attorneys won a binding commitment that requires the state to propose adopting the last three model years of the program no later than 2029, enabling the state to still reach 100% ZEV sales by 2035. This win in Colorado builds on Sierra Club's robust campaign to secure strong standards for car and truck emissions at the federal level and in every state where California's more protective standards have been adopted, proposed, or could be advanced. Sierra Club is currently active in seven other states that are weighing clean car rules similar to Colorado's.
Sierra Club was represented in Colorado's rulemaking by Environmental Law Program attorneys Joe Halso and Jim Dennison, and Sarah Clark mobilized strong grassroots engagement. Sierra Club legal assistants Maddie Lipscomb and Emma Syzmanski supported the team. At the hearing, our expert panel included Joe Halso, Tom Cackette (consultant to EDF), Kathy Harris (NRDC) and Aaron Kressig (Western Resource Advocates). Our intervenor coalition included Sierra Club, NRDC, EDF, WRA, Conservation Colorado and Colorado 350.