In Colorado, transportation is responsible for most of the state’s greenhouse gas emissions, and passenger vehicles account for over half of that portion.

Other states have taken steps to address the contribution of vehicle emissions to total emissions, particularly through the promotion of electric vehicles (EVs). The Advanced Clean Cars II rule (ACCII) is a set of regulations adopted by California’s Air Resources Board to regulate EV sales and further control vehicle emissions. This rule requires that by 2035, 100% of all new vehicle sales in the state be electric. ACCII can significantly boost EVs in both California and the US vehicle market, resulting in substantial economic, health, and emissions reduction benefits. Colorado could consider adopting a similar policy to reduce our greenhouse gas emissions.

In this report, we estimate the benefits of adopting an ACCII program in Colorado at the state and county level. On average, we estimate that under the ACCII program:

• We will have 104 million metric tons of reduction in cumulative CO2e emissions (CO2 and CH4) compared to the baseline scenario between 2035 and 2050 in Colorado.
• Counties are projected to experience up to $2 billion in cumulative savings if the ACCII is adopted.
• Adopting ACCII is projected to save Colorado about $4 billion by 2050 in health damages from exposure to NOx and PM2.5.
• Counties are projected to save up to $500 million in health costs.

Read more about our findings, view our interactive maps, and find more research on climate and the environment on our Colorado Climate Change website.