Last reviewed on May 13, 2014

Greenhouse Gas Inventory Data - 2000 to 2012

Main sources (Wastewater treatment, landfills, pipelines and tanks, enteric fermentation, rice cultivation) of methane
Main sources of methane


The California greenhouse gas (GHG) emissions inventory compiles statewide anthropogenic GHG emissions and sinks. It includes estimates for carbon dioxide (CO2), methane (CH4), nitrous oxide (N2O), sulfur hexafluoride (SF6), nitrogen trifluoride (NF3), hydrofluorocarbons (HFCs), and perfluorocarbons (PFCs). The current inventory covers years 2000 to 2012.

A summary of GHG emissions from 2000 to 2012 is linked below. Annual statewide emission inventories provide the basis for establishing historical emission trends. Trends are useful in tracking progress towards a specific goal or target. There are many factors affecting GHG emissions, including the state of the economy, changes in demography, improved efficiency, and changes in environmental conditions such as drought. A discussion of emission trends for the 2000 to 2012 period and factors affecting different sectors is also provided below.

Data sources include California and federal agencies, international organizations, and industry associations. The calculation methodologies are consistent with the 2006 IPCC guidelines. The current inventory uses global warming potential (GWP) values from the IPCC Fourth Assessment Report, consistent with ARB Scoping Plan Update and USEPA's next national inventory. Full documentation of data sources and methods is available on this web site.

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 in order to maintain a consistent time-series of estimates within the inventory. This approach follows the recommendation for developing GHG inventories discussed in Chapter 7 of the IPCC Good Practice Guidance document: "In order to assess emission trends it is important that the entire time series of emissions, not just the most recent years, be calculated using the changed or refined methods. It is good practice to recalculate historic emissions when methods are changed or refined, when new source categories are included in the national inventory, or when errors in the estimates are identified and corrected." Thus the new inventory may report a different amount of emission/removal for an earlier year than earlier inventories. The results of all methodology changes and historical data updates are discussed in the “Changes in Estimates” section of each chapter of the 2000-2012 Technical Support Document (available in the Publications section).

2000-2012 Inventory Data

The current California GHG inventory covers the years 2000 to 2012. GHG emissions for the years 1990 through 1999 are included in the archived 1990-2004 GHG inventory published in November 2007 (available in the archive section of this site).

The California GHG inventory is categorized in three ways:

  1. Scoping Plan; follows the categories identified in the ARB 2008 Scoping Plan.
  2. Process-oriented categories; follows the IPCC categorization to ensure comparability with international inventories.
  3. Economic sectors; allows for comparison with other ARB emission inventories, which are similarly categorized.

Select a subset of the inventory

bullet Query the inventory by economic sector and/or by activity. This interactive query tool allows you to select a subset of the inventory in a table, view it or download it to your computer, find out how each of the emissions values was estimated, and plot the data. More details on the query tool's help page.

Download the entire inventory