Production-Based Greenhouse Gas Emissions Inventory

Get the latest information and findings from the Air District’s production-based inventory of greenhouse gas emissions.

Many air pollutants have a warming influence on the climate. The Air District prepares emissions inventories of greenhouse gases, or GHGs, known to contribute significantly to climate change, including:

  • Carbon dioxide
  • Methane
  • Nitrous oxide
  • Hydrofluorocarbons
  • Perfluorocarbons
  • Sulfur hexafluoride

The Air District has prepared two greenhouse gas emissions inventories. The production-based emissions inventory described below analyzes GHG emissions that are produced within the Bay Area. The consumption-based emissions inventory analyzes GHG emissions related to goods and service that are consumed within the Bay Area, regardless of where they are produced.  In combination, the two inventories provide a more complete account of the Bay Area’s impact on climate change.

Production-Based GHG Inventory

The most recent production-based GHG emissions inventory is available in the Bay Area Emissions Inventory Summary Report for Greenhouse Gases: Base Year 2011 (PDF). The report summarizes GHG emissions and trends due to human activities, including industrial, commercial, transportation, residential, forestry, and agricultural activities in the Bay Area. Building upon prior inventories, the report provides emission estimates for the year 2011.

Additional supporting documents and data for base year 2011 are also available.

Changes to the Inventory Methodology

The following methodology changes have been made in the 2011 GHG emissions inventory:

  • Updated activity data to reflect current industrial activity, motor vehicle travel, and economic and population growth.
  • Changes to emissions forecasting and backcasting.
  • Addition of benefits from certain regulations, such as the Clean Car Standards Bill (AB 1493), which will result in lower GHG emissions in future years.

Planned Updates

Enhancements to the GHG emissions inventory are an important part of the Air District’s climate protection program. Several near-term updates are underway to supplement the 2011 GHG emissions inventory, including:

  • Adding black carbon emissions. Black carbon is a short-lived climate-forcing pollutant that contributes significantly to global warming and has well-documented health impacts.
  • Including alternate emissions forecasts. Prior forecasts have been for “business-as-usual” scenarios. Future forecasts will include Cap and Trade reductions and explore a range of additional GHG emissions reduction measures.
  • Adding carbon sequestration and emissions from natural and working lands. The natural and working lands GHG emissions inventory will track the removal of carbon dioxide from the atmosphere by Bay Area forests and rangelands and include GHG emissions from these areas.
  • Reassessing methane emissions. Recent studies have found that current evaluation methods are underestimating methane emissions. The Air District will conduct measurement-based assessments to improve methane emission estimates and identify important sources and source regions.

Contact Us

General Information


Meteorology & Measurements
Air Monitoring


Contact Us

Spare the Air Status

Last Updated: 3/24/2021