Last reviewed on August 29, 2013

Query Tool - Help File

How to query California's GHG Inventory by economic sector and/or by activity:

1. Use the drop down lists in the Query Selections box on the left side of the 2000-2011 query tool form (or the 1990 query tool form) to select a particular sector and/or activity. Your current selections will be tracked in the Summary of the current query selections box on the right side.

2. You may then specify the results for your query by choosing a particular greenhouse gas, measurement, global warming potential estimate, unit, and subset of inventory accounting.

3. Press the Get Data button to see the results from your query in a table. In the table, clicking on a column title will sort the table by the attributes in the column, and clicking on any inventory value will take you to a detailed documentation page describing how the value was estimated.

4. At the top of the results table there are two links: Download Data will allow you to retrieve and save the selected inventory data to your computer in a format (.csv) readable by most spreadsheet and database applications, Graph Data will generate a bar plot of these data.

5. Pressing on the back button of your browser will allow you to return to the query tool page to modify your query or to start a new query by pressing the Start Over button.

If some technical terms are unclear to you, please consult the Glossary of Terms Used in Greenhouse Gas Inventories


Sector Selections:

The California GHG Inventory can be queried by economic sector. GHG emissions and sinks are attributed to a Main Sector and three levels of sub-sectors. For instance, choosing: Industrial > Manufacturing > Stone, Clay, Glass & Cement > Cement will select the subset of emissions attributed to cement manufacturing in California. This choice is made with the following steps:

  • first select Industrial in the Main Sector drop down list;
  • then select Manufacturing in the Sub Sector Level 1 drop down list. Notice how it now contains only the choices that are available within the Industrial main sector;
  • then select Stone, Clay, Glass & Cement in the Sub Sector Level 2 drop down list (it contains only choices available within the Manufacturing sub sector);
  • finally, select Cement in the Sub Sector Level 3 drop down list (it contains only choices available within the Stone, Clay, Glass & Cement sub sector).

To modify your query selections you may go back to a drop down list and select All, this will refresh the content of the drop down list and make more choices available again. To start the selection process anew, press the Start Over button.

You do not have to select from the drop down boxes in descending order. This query tool has been designed to update all drop down lists in the "Sector" and "Activity" sections to reflect only subsets of your choice. For instance, one could go directly to the Sub Sector Level 3 drop down list and select Cement to choose the Industrial > Manufacturing > Stone, Clay, Glass & Cement > Cement subset of GHG emissions.

Notes on Sectors:

  • Please be aware that because this is a top down inventory, information may not be available at the lowest level of sectorial detail for all the activities you are interested in. In the case of fuel combustion, natural gas use is metered at the individual user level and statistics are available to track consumption down to a precise sub-sector of the economy. However, data on the use of other fuels is more difficult to disaggregate and may currently be available to one sectorial sub-level. In the case of some activities, such as the use of substitutes of ozone depleting substances, emissions can only be estimated currently for the entire State of California.
  • Be aware that emissions are attributed to their source. For instance, emissions from the production of electricity are attributed to the power plant where fuel is burned to generate the electricity and not to the end user of the electricity. However, natural gas combusted by the end user for heating will be attributed to a more detailed sub-sector of the economy.
  • Please note that the GHG inventory sectors are not standard economic sectors such as those of the US Census Bureau North American Industry Classification System (NAICS) code system. ARB staff is working on structuring future GHG inventories by NAICS code as much as possible within the limits imposed by a top-down inventory.

Activity Selections:

The California GHG Inventory can be queried by activity. Most GHG emissions are estimated on the basis of a given type of activity (Main Activity), such as: fuel combustion, clinker production, animal population, etc. Activity is often divided into different subsets (Activity Subset) such as different fuels for fuel combustion, different species for animal population, etc. For instance, choosing Fuel combustion > Coal will select the subset of emissions attributed to coal burning in California. To do this,

  • first select Fuel combustion in the Main activity drop down list;
  • then select Coal in the Activity Subset drop down list. Notice how it now contains only the fuels that are combusted in California.

To modify your query selections you may go back to a drop down list and select All, this will refresh the content of the drop down list and make more choices available again. To start the selection process anew, press the Start Over button.

You do not have to select from the drop down boxes in descending order. This query tool has been designed to update all drop down lists in the "Sector" and "Activity" sections to reflect only subsets of your choice. For instance, one could go directly to the Activity Subset drop down list and select Residual fuel oil to choose the subset of GHG emissions resulting from all residual fuel oil use in California, both by combustion and by consumption as a feedstock in other processes.

Notes on Activity:

Please be aware that because this is a top down inventory, detailed quantitative information may not be available for all the activities you are interested in. In the case of fuel combustion, natural gas use is metered at the individual user level and statistics are available to track consumption down to a precise sub-sector of the economy. However, data on the use of other fuels is more difficult to disaggregate and may be tracked only down to one sectorial sub-level. In the case of some activities such as the use of substitutes of ozone depleting substances, emissions can only be estimated currently for the entire State of California.


Greenhouse Gas Selections:

In this section you can specify your query results by choosing:

  • A particular Greenhouse Gas to restrict your results to emissions of a single gas. Note, to query for all the emissions of a particular GHG in California: reset the selection process by pressing the Start Over button; select a gas from the GHG drop down list; and press the Get Data button.
  • A Measurement for your results:
    • CO2 equivalent, to report all gases in their equivalent mass of CO2 (by multiplying their mass by their global warming potential).
    • Gas mass to report the actual mass of each of the GHG emitted.
    When you select CO2 equivalent, the global warming potential values used are the 100-year GWP values published in the Second Assessment Report (SAR) of the International Panel on Climate Change of 1996. Updated GWP values have been published in the Fourth Assessment Report of the IPCC of 2007. However, the SAR values are still used by many inventories including the US GHG inventory and thus by ARB to keep California's GHG inventory values comparable to those of the national inventory.
    For details on global warming potentials see: Chapter 2 of the Fourth Assessment Report of the IPCC.
  • A Unit to express your results in: either a) tonnes or b) million metric tonnes. One tonne equals one megagram (MG) i.e. 106 grams
  • A subset of the GHG Inventory Accounting categories:
    • CO2 from biogenic materials: Various renewable fuels (wood, agricultural biomass and landfill or digester gas) are used to produce heat and electricity. The inventory includes only the CH4 and N2O emissions resulting from the combustion of these fuels because the CO2 emissions would have occurred anyway as the biomass decayed. These CO2 emissions, labeled as being "from biogenic materials", are estimated but not included in California's GHG inventory totals. Other fuels, such as used tires, are made in part from renewable materials (natural rubber). In this case, two values for CO2 emissions are estimated in proportion to the renewable and fossil components. Only the CO2 from the fossil component is included in the inventory.
    • Excluded emissions: The Intergovernmental Panel on Climate Change (IPCC) guidelines recommend including only the emissions from domestic aviation and navigation and reporting emissions from international aviation and navigation separately. In the case of a state-level rather than a national inventory, this raises the question of how to treat emissions from interstate flights. Based upon jurisdictional interpretation of IPCC protocols, ARB staff opted to estimate, but not include, emissions resulting from aviation fuel purchased in California and used for interstate flights, as is done for international flights. California's water-borne navigation emissions include emissions from shipping activities which occur in California or within 24 nautical miles of the coast (harbor craft, in-port, and transit emissions). All emissions from shipping activities occurring further than 24 nautical miles from California's coast are excluded regardless of trip origin or destination (in accordance with ARB's pre-existing regulatory approach for criteria pollutants emitted from ocean going vessels). Emissions from international bunker fuels used for navigation (in excess of the amount combusted within 24 nautical miles from the coast) are estimated, but excluded from the inventory in accordance with international convention.
    • Forested lands & wood products: Includes the Net CO2 flux from woody plant species (trees and shrubs) in forests, savannahs and shrublands. The net CO2 flux is estimated by summing CO2 removals from the atmosphere and CO2 emissions to the atmosphere of managed lands and the wood products pool. Removals of CO2 from the atmosphere occur as a result of vegetation biomass growth. Emissions of CO2 to the atmosphere occur as a result of a variety of activities. These include emissions from oxidation of timber harvest slash, fuel wood, biomass consumed in wildfires, other disturbance (land use change or unspecified), or from the decomposition of landfilled or composted wood products consumed in the state. CO2 removals and emissions by urban forests are not included. CO2 removals and emissions on crop lands are not estimated, pending further study.
      This spreadsheet also includes CH4 and N2O emissions resulting from fires and other disturbances occurring in forested lands.
    • Included emissions: Emissions that are neither Excluded emissions nor Emissions from biogenic materials (as defined above) are included in California's GHG emissions inventory totals.

Query Results:

Once done with query selections and results specification, press on the Get Data button and the query tool will generate a new web page with a table containing the results of your query. These are the actions you may take on the results:

  • Sort the results by a given column. Clicking on the header in one of the columns will sort the table of results by the attributes contained in the column. For instance, clicking on "Inventory Accounting" will sort results by inventory accounting subset, and clicking on "Greenhouse Gas" will sort by Gas.
  • Find out how a value was estimated. Clicking on any of the estimated values will take you to a documentation page. Each of the documentation pages features the following items:
    • The date on which the page was last updated
    • The identification of the estimate: its IPCC category of emission and removal, economic sector classification, the greenhouse gas estimated and the year of the estimate
    • The estimated amount of emission or removal (both the mass of gas and its CO2 equivalent), the units it is expressed in, the basis of the estimate (the algebraic formula or the name of the mathematical model), and the reference for the origin of the model or formula.
    • The amount of activity that resulted in the GHG emission or removal (if applicable), the basis of the amount (data point, compilation of statistics, result from a calculation, mathematical model) and the reference for the source of the amount. In the case where the amount of activity is itself the result of a calculation, the formula and its source are given.
    • The parameters and constants used in the calculation of the GHG estimate and/or the amount of activity. The value and units of these parameters and constants and the reference for their source is also listed.
    • The calculated amount of greenhouse gas emitted per unit of activity.
  • Download the results to your computer. Click on Download Data at the top of the results table and the content of the table will be downloaded to your computer in a format (.csv) that is compatible with most spreadsheet and database applications. This allow you to save your queries for subsequent retrieving and analysis.
  • Graph the results. Click on Graph Data at the top of the results tables and the query tool will generate a new page with a bar plot and a table summarizing emissions by greenhouse gas. If you have chosen Gas mass as the Measurement for your results the bars for the GHGs will be side by side, if you have chosen CO2 equivalent the bars for the GHGs will be stacked. Please note that if the emissions of one of the gases (typically CO2) are much larger than that of the others (e.g. CH4, N2O), the bars for the gases emitted in smaller amounts may not show in the plot.
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