Emissions Inventories

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.

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.

The Air District compiles and reports inventories of emissions for criteria air pollutants, greenhouse gases, and toxic air contaminants for the Bay Area.

  • Emmisions Inventory Summary
    Get an overview of the regional inventory of criteria air pollutants in the nine-county Bay Area
  • Emissions Lookup Tool
    Get an illustrative breakdown of emissions by pollutant, year, source sector and sub-sector
  • Methodology Documentation
    Get a detailed description of how emissions are estimated.
  • Emissions Assessment & Research
    Get a glimpse into research projects and studies that the agency is using to improve knowledge of emissions inventories

Contact Us

Assessment, Inventory, and Modeling Division


Contact Us

Spare the Air Status

Last Updated: 9/13/2023