Regional GHG Inventory Emissions Lookup Tool
Get an illustrative breakdown of greenhouse gas (GHG) emissions by pollutant, year, county, source sector and sub-sector.
Introduction
The Air District has developed the GHG Inventory Lookup Tool to provide an interactive way to explore the Bay Area’s GHG emissions inventory from 1990 through 2050. The data presented in this tool support the Bay Area Regional Climate Action Planning (BARCAP) Initiative for the San Francisco-Oakland-Berkeley Metropolitan Statistical Area, available at the Bay Area Regional Climate Action Plan web page.
All emissions displayed in the tool are reported in units of million metric tons of CO2 equivalent (MMTCO2e).
The tool allows users to explore the following:
- GHG Emissions Decomposition Tree – provides a hierarchical breakdown of regional emissions by sector and subsector.
- Emissions by County Bar Chart – displays each county’s contribution to total regional GHG emissions and allows comparisons by pollutant, year, and sector.
- Pollutant Pie Chart – shows the relative contribution of each pollutant to the total GHG emissions by county, sector, and year.
- Emission Timeseries – provides a time series breakdown of emissions by sector. sub-sector, and county from years 1990 to 2050
Emissions Lookup Tool
How To Use
Watch the How-to-video for a guided walkthrough on how to use the emissions lookup tool, and/or follow the steps below:
- Select a year between 1990 to 2050.
- In the “Emissions by Sector” Decomposition Tree, click on a sector (Level 1) to expand the hierarchy and to view emissions contribution by subsector (Levels 2-3).
- To filter the emissions in the Decomposition Tree by multiple selections (such as county and pollutant), hold the CTRL key down while making the selections on the left menu.
- A summary of the current filter selection (year, county, pollutant) is always displayed on the right side of the Decomposition Tree.
- To display the underlying data in table format, right-click any visuals and select “show as a table.”
- In the “Emissions by County” Bar Chart to the left, click on a county bar to filter other visuals and display emissions specific to that county.
- To view emissions specific to a pollutant, click on any pollutant name in the “Emissions by Pollutant” Pie Chart at the left bottom.
- Additional drill-through functionality is available by right-clicking the Decomposition Tree elements to view data by time series and/or category.
- To access the “Emissions Time Series” directly, click the button “Go to Time Series” on the top of the home page,
- In the “Emissions Time Series”, a user can look at the GHG emissions trends for any combination of sector, subsectors, county, and also specify the time period.
- Use the “Clear Selection” option to reset all visuals and filters, and “Return to Main Page” to go to the home page.
Inventory Download
The entire regional GHG inventory dataset that is displayed in the GHG Emissions Lookup Tool can be downloaded as an excel spreadsheet: BY2022 Bay Area Regional GHG Emissions Inventory. This spreadsheet includes a detailed README tab that describes the dataset and provides an overview of the data contained within each column.
Caveats
Users should consider the following limitations and uncertainties when interpreting the data presented in this tool.
- The inventory represents estimated annual emissions from 1990 through 2050 using 2022 as the base year. The 2022 inventory includes reductions/controls from adopted and in-effect regulations but does not reflect controls associated with non-enforceable climate protection guidelines or recommended policies.
- Emissions estimates for 1990–1999 were extrapolated from year 2000 data and therefore have greater uncertainty than estimates for more recent inventory years.
- Emissions data beginning in 2000 are based on methodologies consistent with state and federal approaches and incorporate socioeconomic indicators to forecast and backcast emissions trends.
- Local climate action measures and enforceable regulatory ordinances adopted by individual counties or cities are not included.
- Rules and regulations adopted through 2024 were incorporated into future-year projections. For example, amendments to Regulations 9-4 and 9-6 are reflected in the natural gas leakage categories. Regulatory amendments adopted after 2024 are not included.
- Projected emissions beyond 2023 are based on a business-as-usual scenario and should not be interpreted as forecasted emissions to reflect future policy outcomes.
- For additional planning context and details regarding methodologies, assumptions, and results, please refer to the Air District’s Comprehensive Climate Action Plan developed under the BARCAP initiative and the companion document: Summary Report for Greenhouse Gases for Base Year 2022.
Last Updated: 2026/8/25