Policy Framework for Addressing Methane in Colorado’s Greenhouse Gas Regulations

The Clean Air Task Force, Earthjustice, and Western Resource Advocates recommend that Colorado move away from a "single-basket" approach—which measures all greenhouse gas reductions in CO2 equivalence (CO2e)—toward a "two-basket" framework. This proposed system would require both short-lived pollutants (methane) and long-lived pollutants (CO2 and N2O) to decline on their own steady trajectories, such as both being reduced by 50% below 2005 levels by 2030. The authors argue that a single-basket approach creates problematic trade-offs, where high Global Warming Potential (GWP) values for methane could incentivize polluters to prioritize low-cost methane reductions over the long-term CO2 reductions necessary to stabilize the climate. The document asserts that the AQCC has the legal authority under HB 19-1261 to implement this separate tracking to ensure the state meets its targets of 26% reduction by 2025, 50% by 2030, and 90% by 2050.

• The authors recommend a "two-basket" policy framework to ensure that short-lived and long-lived pollutants each decline on a steady trajectory, preventing trade-offs between the two.
• A "single-basket" approach using CO2 equivalence (CO2e) can lead to unintended consequences, such as reducing the incentive for near-term CO2 mitigation if a high Global Warming Potential (GWP) is used for methane.
• Using a 20-year GWP for methane in a decarbonization program may allow polluters to avoid significant CO2 reductions by claiming high credits for low-cost methane abatement.
• Applying a higher GWP for methane can counter-intuitively extend the timeframe for eliminating methane pollution by increasing the baseline emissions in CO2e.
• Colorado's 2019 GHG Inventory showed methane emissions increased from 0.96 million metric tons in 2005 to an estimated 1.2 million metric tons in 2015.
• The AQCC has the legal authority to adopt a two-basket approach as it is consistent with the mandates of HB 19-1261 to reduce greenhouse gas pollution by 26% by 2025, 50% by 2030, and 90% by 2050.

APA

McCabe, D., Cooley, R., Roy, R., Tellinghuisen, S., & Overturf, E. (2020). Policy Framework for Addressing Methane in Colorado’s Greenhouse Gas Regulations. Clean Air Task Force. https://cdn.catf.us/wp-content/uploads/2020/09/21092651/AQCC-GWP-methane-June-16-2020-Final.pdf

Chicago

McCabe, David, Robin Cooley, Rumela Roy, Stacy Tellinghuisen, and Erin Overturf. Policy Framework for Addressing Methane in Colorado’s Greenhouse Gas Regulations. Clean Air Task Force, 2020. https://cdn.catf.us/wp-content/uploads/2020/09/21092651/AQCC-GWP-methane-June-16-2020-Final.pdf.

Wikipedia

{{cite press release |last1=McCabe |first1=David |last2=Cooley |first2=Robin |last3=Roy |first3=Rumela |last4=Tellinghuisen |first4=Stacy |last5=Overturf |first5=Erin |title=Policy Framework for Addressing Methane in Colorado’s Greenhouse Gas Regulations |publisher=Clean Air Task Force |date=16 June 2020 |url=https://cdn.catf.us/wp-content/uploads/2020/09/21092651/AQCC-GWP-methane-June-16-2020-Final.pdf |access-date=23 October 2026 |via=Climate Insights Directory}}

BibTeX

@misc{mccabe2020policy, author = {McCabe, David and Cooley, Robin and Roy, Rumela and Tellinghuisen, Stacy and Overturf, Erin}, title = {{Policy Framework for Addressing Methane in Colorado’s Greenhouse Gas Regulations}}, publisher = {Clean Air Task Force}, year = {2020}, month = jun, url = {https://cdn.catf.us/wp-content/uploads/2020/09/21092651/AQCC-GWP-methane-June-16-2020-Final.pdf}, urldate = {2026-10-23}, note = {Indexed by Climate Insights Directory} }