2000-2021 GHG Inventory (2023 Edition)
Graphic: California's greenhouse gas emissions in 2021 broken out by economic sector
California Greenhouse Gas Emissions from 2000 to 2021: Trends of Emissions and Other Indicators
California Greenhouse Gas Emissions from 2000 to 2021: Trends of Emissions and Other Indicatorssummarizes and highlights the major annual changes and notable longer-term trends of each year's GHG inventory. It provides easy-to-read graphs and explanations to illuminate California's progress in its commitment to reduce climate-changing emissions.
2000–2021 GHG Emissions Trends Report Dataused for figures in the report is available for download.Links to additional data and documentation can be found below.
Note: Carbon dioxide equivalent values are calculated using the IPCC's Fourth Assessment Report 100-year Global Warming Potential values.
GHG Inventory Query Tool
Background
California's annual statewide greenhouse gas (GHG) emission inventory is an important tool for establishing historical emission trends and tracking California's progress in reducing GHGs. In concert with data collected through various California Global Warming Solutions Act (AB 32) programs, the GHG inventory is a critical piece in demonstrating the state's progress in achieving the statewide GHG target. The inventory provides estimates of anthropogenic GHG emissions within California, as well as emissions associated with imported electricity; natural sources are not included in the inventory. CARBis responsible for maintaining and updating California's GHG Inventory per H&SC section 39607.4.
The inventory includes estimates for carbon dioxide (CO2), methane (CH4), nitrous oxide (N2O), and fluorinated gases with high global warming potentials (High-GWP) which includes hydrofluorocarbons (HFCs), perfluorocarbons (PFCs), sulfur hexafluoride (SF6), and nitrogen trifluoride (NF3). It uses an inventory scope and framework consistent with international and national GHG inventory practices. An updated emission inventory is published annually to include additional years and improved estimation methods. Archives of all previous inventory data and documentation are available on thearchivepage.
What are Greenhouse Gases?
Global Warming Potentials (GWPs) for GHG Emissions
Glossary of GHG Inventory Terms
Data Overview
Statewide emission estimates rely on state, regional or federal data sources, and on aggregated facility-specific emission reports from CARB'sMandatory GHG Reporting Program(MRR). Calculation methodologies are consistent with the2006 IPCC Guidelines. The current inventory uses 100-year global warming potential (GWP) values from the IPCC Fourth Assessment Report.
In preparation for each new edition of the inventory, recalculations are made to correct errors, incorporate new methodologies or, most commonly, to reflect changes in statistical data supplied by other agencies. Emission estimates are recalculated for all years to maintain a consistent time-series following IPCC recommendations for developing GHG inventories. Thus the new inventory may report a different emission level for an earlier year than previous inventory editions.
The California GHG inventory is categorized in three ways:
- Scoping Plan; follows the categories identified in theAB 32 Scoping Plan.
- Economic sectors; allows for comparison with other CARB emission inventories, which are similarly categorized.
- IPCC process-oriented categories; follows the IPCC categorization to ensure comparability with international inventories.
The table below provides a crosswalk among the three categorization schemes.
Inventory Categorization Crosswalk
2023 Inventory Documentation
2000–2021 Emissions Trends Report
2000–2021 Trends Figure Data
GHG Inventory Documentation Index
Technical Documentation
CARB has a fully detailed Technical Support Document, last updated for the 2016 edition of the inventory. Since then, staff have prepared Inventory Updates Documents that specify all methodology changes made to the inventory for each year. A compilation of these documents is found below and can be used in conjunction with the full Technical Support Document to show all information for the methodologies of the inventory calculations.
Technical Support Document(2016 Edition)
2000–2021 Inventory Updates Documentation(2023 Edition)
2000-2020 Inventory Updates Documentation(2022 Edition)
Supplemental Method Updates Document (2017 - 2021 Edition)
Data
Summaries of GHG Emissions by Categorization Group
Scoping Plan Categorization
Economic Sector Categorization
IPCC Categorization
Totals by Gas
GHG Emission Summaries Segregated by Gas
Categorization | CO2Only | CH4Only | N2O Only | High-GWP Only |
|---|---|---|---|---|
Scoping Plan | CO2 - Scoping | CH4 - Scoping | N2O - Scoping | High-GWP - Scoping |
Economic Sector | CO2 - Economic | CH4 - Economic | N2O - Economic | High-GWP - Economic |
IPCC Category | CO2 - IPCC | CH4 - IPCC | N2O - IPCC | High-GWP - IPCC |
FullInventory
Scoping Plan Categorization
Economic Sector Categorization
IPCC Categorization
Fuel Combustion and Heat Content
Download a detailed list of all fuel combustion data used to calculate the GHG emissions by sector and activity. The categorization in this workbook matches the "Economic Sector Categorization" inventory spreadsheet above.
Guidance & Resources for Working with GHG Inventory Data
Cogeneration Emissions
The CARB Regulation for the Mandatory Reporting of GHG Emissions (MRR) is a primary data source for the statewide inventory but emissions are categorized differently in the two programs. Industrial cogeneration (also known as Combined Heat and Power, or CHP) represents the major categorization difference. The guidance document below provides instruction for working with and crosswalking between the two datasets. A spreadsheet provides GHG inventory industrial cogeneration emissions disaggregation to facilitate comparison with MRR data.
2012–2021 Industrial Cogeneration Breakout
Additional Information
AB 2195 Report on Upstream Emissions of California’s Natural Gas Consumption
AB 2195 requires CARB “to quantify and publish annually the amount of greenhouse gas emissions resulting from the loss or release of uncombusted natural gas to the atmosphere and emissions from natural gas flares during all processes associated with the production, processing, and transporting of natural gas imported into the state from out-of-state sources.” Most of the emissions quantified in the AB 2195 report occurred outside of California borders; and therefore, are not added to the GHG Inventory total pursuant to the inventory boundary specified in AB 32. Link to the report:
AB 2195 Out-of-State Natural Gas Emissions
Other Resource Links
2020 Business as Usual (BAU) GHG Emissions Projection
Short Lived Climate Pollutant (SLCP) Inventory
Original (1990-2004) Inventory
GHG emissions estimates for years prior to 2000 are included in the 1990–2004 GHG Emission Inventory published in November 2007, and are included in the1990 Inventory Query Tool.This inventory, and associated 1990–2004 Inventory Data and Documentation,provided the basis for developing therequired by theGlobal Warming Solutions Act of 2006 (AB 32).
