CA Greenhouse Gas Emission Inventory Program

Scope

In 2006, California passed Assembly Bill 1803, which tasks the California Air Resources Board (CARB) with creating an inventory of the state’s GHG emissions. The GHG Emission Inventory Program collects and compiles data on GHG emissions from economic sector sources including agriculture, commercial, forestry, electrical, industrial, residential, and transportation. This program works in concert with various initiatives under the California Global Warming Solutions Act to show progress toward meeting the state’s GHG reduction goals and mitigation, aiming to achieve carbon neutrality by 2045 or earlier.

Regulatory citations

• AB 32 — California Global Warming Solutions Act of 2006
• AB 1803 — Committee on Budget

Key definitions

• California Air Resources Board (CARB): The regulatory agency that oversees all efforts to control air pollution and conserve air quality standards in the state.
• California Global Warming Solutions Act: Requires CARB to develop statewide initiatives that will reduce GHG emissions to 40 percent below the 1990 level by 2030.
• Carbon neutrality: The result of all GHG emissions being counterbalanced by carbon sequestration.
• Greenhouse gas (GHG): Any gas that absorbs infrared radiation in the atmosphere. It includes, but isn’t limited to, carbon dioxide, hydrochlorofluorocarbons, hydrofluorocarbons, methane, nitrous oxide, ozone, perfluorocarbons, and sulfur hexafluoride.
• Mandatory Reporting of Greenhouse Gas Emissions (MRR) Program: Requires certain facilities to submit GHG emissions data annually to CARB.

Summary of requirements

To determine GHG emissions from a particular region, CARB uses both a top-down and bottom-up approach. The top-down approach utilizes data from various federal and state government agencies to estimate GHG emissions. The bottom-up approach uses individual facility data collected through the MRR Program to calculate emissions from a particular source category.