Recommendations For Implementing a Carbon Tax in Boulder, Colorado

Abstract

Boulder, Colorado, a small city located approximately 30 minutes outside of Denver, has historically funded its Climate Action Plan through a tax on electricity (“CAP tax.”) In addition to generating revenue, the CAP tax serves as a carbon pricing mechanism. With the CAP tax expiring in 2023, this report examines what updates the city could make to the tax so it: 1) continues to generate revenue, 2) incorporates other fuels such as natural gas, and 3) better reflects the societal cost of greenhouse gas emissions. We provide recommendations and next steps to the city based on our analysis of the city’s regulatory authority, research on worldwide carbon pricing systems, and quantitative model results. We find that a charge reflecting the full social cost of carbon (~$42 in 2020) could greatly increase revenue beyond historical CAP tax levels, and that incorporating the natural gas sector at a lower rate could provide long-term funding stability for the city.