Emissions Inventories

Updated 4/1/2026

Learn about the emissions inventories of criteria air pollutants, greenhouse gases, and toxic air contaminants that the Air District prepares for the San Francisco Bay Area.

Updated 4/1/2026

An emission inventory is a periodic accounting of emission quantities, sorted by pollutant, location, and characteristic group of air pollution sources. An emission inventory typically accounts for emissions over time, including past years and projections for future years. A representative year is usually chosen as the basis to estimate emissions for future years. This is referred to as a base year. 

The Air District uses emission inventories for many purposes, such as providing inputs for regional air quality modeling to estimate pollutant concentrations and exposures, highlighting emission sources to target for future rulemaking or regulation amendments, and providing direction for air quality planning and policy formulation to attain clean air goals.

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Assessment, Inventory, and Modeling Division

aim@baaqmd.gov

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Last Updated: 4/1/2026