Colorado Greenhouse Gas Inventory | Department of Public Health ... - Colorado Department of Public Health and Environment

Colorado Greenhouse Gas Inventory | Department of Public Health & Environment

Greenhouse Gas Inventory

The goal of the GHG Inventory Report is to provide the most complete, accurate, precise, consistent, and comparable picture of emissions resulting from activities within the State and spanning all the years of concern. The science of climate change is rich in scope and complexity and is always improving. The state works to use the best available data and evaluation methods each time it creates an updated GHG Inventory Report. This can mean numbers and trends may change from one inventory report to another. This is a normal part of how science works and helps make sure that the information in reports is becoming more accurate over time.

In 2019, Senate Bill 19-096(SB 19-096) was adopted to require facilities that emit large amounts of greenhouse gases to monitor and report their emissions to the state. This bill supported the Executive Order D 2017-015 which directed the Department to propose a greenhouse gas (GHG) reporting rule mirroring the federal reporting rule under 40 CFR, Part 98, among other requirements. Also in 2019, House Bill 19-1261 required the Division to compile statewide greenhouse gas inventories and report them to the General Assembly. Using reported data and other data sources, such as the U.S. Environmental Protection Agency’s State GHG Emissions and Removals dataset or the State Inventory Tool, the state produces an updated GHG Inventory Report every two years, including past, recent, and projected GHG emissions for the following sectors:

- Agriculture
- Coal Mining
- Electric Power
- Industrial Processes and Product Use
- Land Use, Land Use Change, and Forestry
- Natural Gas and Oil Systems
- Residential, Commercial, and Industrial (RCI) Fuel Use
- Waste Management

The GHG Inventory is published every two years starting in 2019 per SB 19-096, while the first publication was released in 2014. The next inventory will be released in 2023. Major changes anticipated in the 2023 release include:

- There will be changes to data sources and methods.
- There will be a change in global warming potentials used, going from the United Nations Intergovernmental Panel on Climate Change 4th Assessment Report (AR4) to the 5th (AR5).
- There will be changes in total emissions, the baseline, and sector-wide emissions.
- The report will be longer and more in depth than previous reports and will work to better align with the national inventory.
- There will be improved transparency with all the supporting data made publicly available.

Past GHG Inventory Publications:

2021 Colorado Greenhouse Gas Inventory
2019 Colorado Greenhouse Gas Inventory
2014 inventory report update
2007 inventory report update
2002 inventory report update
1998 inventory report update

Between inventory updates, current information on critical metrics that impact greenhouse gas emissions can be found in the Greenhouse Gas Metrics dashboard, available in both English and Spanish.

For information related to public meetings and other stakeholder engagement opportunities, please refer to the Stakeholder Opportunities and Involvement section below.

The 2014, 2019, and 2021 inventories primarily relied on EPA’s State Inventory Tool (SIT) to generate GHG emissions data for the inventories. However, beginning with the 2023 inventory, emissions reported to the State of Colorado per the requirements of AQCC Regulation 22, Part A, and AQCC Regulation 7, Part D., Sections IV. & V., will be utilized as much as possible, as directed under SB 19-096, and be supplemented with calculated emissions from fuel sales data provided to the Air Pollution Control Division by the Department of Revenue, as well as results from the SIT. As reporting of GHG emissions data directly to the State of Colorado was not required until 2021 (for emissions occurring in 2020), the 2019 and 2021 inventories relied primarily on modeled data from the SIT modules. For inventories published in 2023 and beyond, the emissions data will represent a combination of reported and modeled data.

The historical data presented in the currently published inventories is based on various modules in the SIT. The modules are updated regularly by EPA with current activity data and published with those updates annually to reflect real-world data as it becomes available. This update and publication process presents a lag in the availability of historical data the SIT can generate. For instance, the SIT data utilized in the 2021 inventory only includes historical emissions from the SIT through 2018. Because future inventories will continue to be reliant on the SIT to a degree for historical emissions, those inventories will also have a year or two lag in the historical emissions that are presented.

SIT modules used for the 2021 inventory report
SIT modules used for the 2019 inventory report
SIT modules used for the 2014 inventory report

The Air Pollution Control Division has published a report to meet requirements placed upon the Division in the “Resolution to Ensure Greenhouse Gas Reduction Goals Are Met” adopted by the Colorado Air Quality Control Commission (AQCC) on October 23, 2020. The Division conducted its evaluation for the report in August 2022 as required by the resolution and submitted the report to the AQCC.

AQCC GHG Reduction Goals Progress Report

To meet the requirements from House Bill 19-1261, The Air Pollution Control Division must track progress toward state greenhouse gas (GHG) reduction goals, provide any updated cost-benefit analysis developed for rules adopted to attain the goals, and make recommendations on future legislative action to address climate change. The Division submitted its first report to the Colorado General Assembly in December 2021.

GHG Emissions Reduction Progress Report to Colorado Legislature

GHG Inventory Fact Sheet in English and Español

The anticipated timeline for the 2023 Inventory is as follows:

- October 17 and 24, 2023 - Public Informational Meetings via Zoom
- November - December, 2023 - Public comment period for draft GHG Inventory Report
- November - December, 2023 - Internal review of comments, revisions of report
- By January, 2024 - Final report and executive summary published
- Early 2024 - Briefing about results to Air Quality Control Commission

Here are some ways you can participate in the GHG Inventory process:

- Attend a public meeting to learn more and share your ideas. ( Register here for 10/24.)
- Share your ideas and concerns by filling out this comment form. (Note all comments are publicly available but your contact information will not be posted.)
- Learn more about past state GHG inventory reports and data sources at our website.
- Stay up-to-date on this GHG Inventory Report and other efforts the Colorado Department of Public Health and Environment's is taking to address climate change and other air quality issues by signing up for email updates.

Previous stakeholder engagement efforts:

Contact Us

If you have any questions or comments about the GHG Inventory, please email climatechange@state.co.us with subject line "GHG Inventory".

Stay up-to-date on the Colorado Department of Public Health and Environment's efforts to reduce GHGs, Climate Equity, and other air quality issues by signing up for e-mail updates.