Last reviewed on
August 12, 2019
Query Tool - Help File
1. Use the drop down lists in the Query Selections box on the left side of the
2000-2017 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
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.
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.
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 Fourth Assessment Report (AR4) of the International
Panel on Climate Change of 2007. Updated GWP values have been published
in IPCC's Fifth Assessment Report in 2014. However, the AR4 GWP values
Have been used by ARB's revised Scoping Plan and will be used by USEPA National GHG
Inventory starting in 2015. AR4 GWP values are thus used here for compatibility with these documents.
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
- GHG Inventory Accounting categories:
- Included emissions: Emission categories that are included in California's Greenhouse Gas Emission Inventory.
These emission categories are used to track progress towards reducing California's GHG emissions to 1990 levels.
- CO2 from biogenic materials:
Various renewable fuels (wood, agricultural biomass and landfill or
digester gas) are used to produce heat and electricity. CO2 emissions
from these sources are estimated but not included in the California GHG
emission inventory because the emissions would have occured naturally
as the biomass decayed and therefore do not yield a net increase in
atmospheric CO2. However, CH4 and N2O from these sources are
cateogrized as included emissions
because they result from the combustion of these fuels and would not
otherwise be emitted. Some fuels, such as used tires, are made in part
from renewable materials (natural rubber). In this case two CO2
emission values are estimated in proportion to the renewable and fossil
components of the fuel. Only the CO2 from the fossil component is
categorized as included emissions and counted towards California's GHG emission 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 estimates, but does not include, emissions
resulting from aviation fuel purchased in California and used for
interstate flights, consistent with the treatment of emissions from
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:
Data only available for 1990 as ARB staff develop a new methodology to
estimate GHG emission from Forested lands. 1990 data 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 biomass consumed in wildfires, oxidation
of timber harvest slash, fuel wood, 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 category also includes CH4 and N2O emissions resulting from fires and other disturbances occurring in forested lands.
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.