GHG Emissions Taxonomy

Definition

A GHG Emissions Taxonomy is any well organized, comprehensive Taxonomy of GHG Emissions sources. In the language of GHG Accounting the elements of the taxonomy are sometimes denoted as Sectors, not to be confused with Business Sector.

GHG Corporate Accounting Standard

The GHG Protocol corporate accounting identifies the following high level categories:

• Stationary Combustion: combustion of fuels in stationary equipment such as boilers, furnaces, burners, turbines, heaters, incinerators, engines, flares, etc.
• Mobile Combustion: combustion of fuels in transportation devices such as automobiles, trucks, buses, trains, airplanes, boats, ships, barges, vessels, etc.
• (Industrial) Process Emissions: emissions from physical or chemical processes such as CO₂ from the calcination step in cement manufacturing, CO₂ from catalytic cracking in petrochemical processing, PFC emissions from aluminum smelting, etc.
• Fugitive Emissions: intentional and unintentional releases such as equipment leaks from joints, seals, packing, gaskets, as well as fugitive emissions from coal piles, wastewater treatment, pits, cooling towers, gas processing facilities, etc.

GHG Project Accounting Standard

Under the GHG Project Protocol, there are five general GHG source categories :

• Combustion Emissions from generating grid-connected electricity;
• Combustion Emissions from generating energy or off-grid electricity, or from flaring;
• Industrial Process Emissions - e.g., carbon dioxide (CO2) from the production of clinker for cement;
• Fugitive Emissions - e.g., GHG leaks from pipelines; and
• Waste Emissions - e.g., GHG emissions from landfills.

GPC Cities Accounting Standard

Under the Global Protocol for Community-Scale Greenhouse Gas Inventories, there are six general GHG source sectors :

• Stationary Energy
• Transportation
• Industrial Process Emissions (IPPU) - e.g., carbon dioxide (CO2) from the production of clinker for cement;
• Agriculture, Forestry and Other Land Use (AFOLU)
• Waste Emissions - e.g., GHG emissions from landfills.
• Any other emissions occurring outside the Geographic GHG Boundary as a result of city activities (Scope 3 GHG Emissions)

Emissions from these sectors shall be sub-divided into subsectors and may be further sub-divided into sub-categories.

GHG Emissions by Source Geometry

GHG Emissions Sources can be categorized by geometry as follows:

• Point Source GHG Emissions where emission can be idealized as occuring from a wikipedia:Point source
• Linear Source GHG Emissions where emissions can be idealized as occuring from a wikipedia:Linear source
• Areal Source GHG Emissions where emissions can be idealized as occuring from a wikipedia:Area source (pollution)

The above geometrical classification depends heavily on the spatial and temporal resolution of emissions measurement.