**SIMAP emission factors: 2021 version**

Comprehensive list of references used to calculate SIMAP emission factors, organized by reference

Updated January 2022

**US GHG Inventory Annexes/Annex tables (Most widely used source in SIMAP emission factors): **

https://www.epa.gov/ghgemissions/inventory-us-greenhouse-gas-emissions-and-sinks-1990-2019

- Table A-40: C Content Coefficients, used for many fuels (stationary and mobile).
- Table A-41: Annually Variable C Content Coefficients.
- Table A-42: Key Assumptions fpr Estimating CO2 Emissions
- Table A-43: Annually Variable C Content Coefficients by Year
- Table A-91: CH4 and N2O Emission Factors by Fuel Type and Sector.
- Table A-93: Energy Consumption by Fuel and Vehicle Type. Used in the CH4 and N2O per Gallon Calculations.
- Table A-95: Vehicle Miles Traveled for Gasoline On-Road Vehicles. Used in the CH4 and N2O per Gallon Calculations.
- Table A-96: Vehicle Miles Traveled for Diesel On-Road Vehicles. Used in the CH4 and N2O per Gallon Calculations.
- Table A-99: Detailed Vehicle Miles Traveled for Alternative Fuel On-Road Vehicles. Used in the CH4 and N2O per Gallon Calculations.
- Table A-99: Age Distribution by Vehicle/Fuel Type for On-Road Vehicles, 2014. Used in the CH4 and N2O per Gallon Calculations.
- Table A-101: VMT Distribution by Vehicle Age and Vehicle/Fuel Type, 2014. Used in the CH4 and N2O per Gallon Calculations.
- Table A-115: Emission Factors for CH4 Emissions from Non-Road Mobile Combustion. Used for Jet fuel.
- Table A-177: Annex I Countries’ Implied Emission Factors for Cattle by Year. Used for Cattle EFs.
- Table A-178: CH4 Emissions from Cattle.
- Table A-179: Emission Factors for Other Livestock.
- Table A-181: CH4 Emissions from Enteric Fermentation. Used for Cattle EFs.
- Table A-184: Livestock Population.
- Table A-195: Total Methane Emissions from Livestock Manure Management.
- Table A-196: Total (Direct and Indirect) Nitrous Oxide Emissions from Livestock Manure Management.
- This source is also used for wasteater CH4 and N2O emission factors

**Bureau of Transportation Statistics Tables:**

** **https://www.bts.gov/topics/national-transportation-statistics

- Table 1-11: Number of U.S. Aircraft, Vehicles, Vessels, and Other Conveyances. Used in the MPG calculations.
- Table 4-11: Light Duty Vehicle, Short Wheel Base and Motorcycle Fuel Consumption and Travel. Used in the MPG calculations and the CH4 and N2O per gallon calculations.
- Table 4-15: Bus Fuel Consumption and Travel. Used in the MPG calculations.
- Table 4-20: Energy Intensity of Passenger Modes (Btu per passenger-mile). Used in the EF Mobile Calculations.
- Table 4-24: Energy Intensity of Transit Motor Buses. Used in the MPG calculations.

**American Public Transportation Fact Book (APTA) Tables and Annex Tables: **

- Table 1: National Totals for selected Modes. Used in the MPG calculations.
- Table 3: Passenger Miles by Mode (A and B). Used in the MPG calculations.
- Table 9.11: Summary Statistics for Commuter Rail Operations, 1984–2016. Used in the MPG calculations.
- Table 9.12: Summary Statistics for Rail Transit Operations, 1970–2016. Used in the MPG calculations.
- Table A.14: Commuter Rail Fuel Use. Used in the MPG calculations.
- Table A.15: Transit Rail Fuel Use: Used in the MPG calculations.

**EPA Motor Vehicle Emission Simulator (MOVES):**

https://www.epa.gov/moves/latest-version-motor-vehicle-emission-simulator-moves

- Used in the CH4 and N2O per gallon calculations

**2006 IPCC Guidelines for National GHG inventories:**

https://www.ipcc-nggip.iges.or.jp/public/2006gl/pdf/4_Volume4/V4_11_Ch11_N2O&CO2.pdf

- Volume 4 Chapter 11 - N2O EMISSIONS FROM MANAGED SOILS, AND CO2 EMISSIONS FROM LIME AND UREA APPLICATION. Used in Fertilizer Calculations.
- Equation 11.1
- Equation 11.9
- Equation 11.10

**US Energy Information Administration (EIA) Monthly Energy Review (MER): **

https://www.eia.gov/totalenergy/data/monthly/

- Table A1: Approximate Heat Content of Petroleum and Other liquids. Used in the GHG Stationary Combustion Calculations and the EF Mobile Calculations.
- Table A2: Approximate Heat Content of Petroleum Production, Imports, and Exports. Used in the GHG Stationary Combustion Calculations.
- Table A3: Approximate Heat Content of Petroleum Consumption and Fuel Ethanol. Used in the GHG Stationary Combustion Calculations.
- Table A4: Approximate Heat Content of Natural Gas. Used in the GHG Stationary Combustion Calculations.
- Table A5: Approximate Heat Content of Coal and Coke Coal. Used in the GHG Stationary Combustion Calculations.

**The Climate Registry 2020 Default Emission Factor Document:**

https://theclimateregistry.org/wp-content/uploads/2022/11/2022-Default-Emission-Factors-Final.pdf

- Table 1.1: Default Factors for Calculating CO2 Emissions from Combustion of Fossil Fuel and Biomass. Used for Biomass CO2 emissions.

**US EPA Documentation for Greenhouse Gas Emission and Energy Factors Used in the Waste Reduction Model (WARM) – Management Practices Chapters: **

- Exhibit 5-1: Gross GHG Emissions from MSW Combustion. Used in the GHG Stationary Combustion Calculations.

**EPA Emissions & Generation Resource Integrated Database (eGRID)**

https://www.epa.gov/energy/emissions-generation-resource-integrated-database-egrid

- Data file, SRL tab by eGrid subregion. Emission factors in terms of ‘total output emission rate (lb/MWh)’ used to calculate purchased electricity emission factors for scope 2 location-based method.

**2021 Green-e Residual Mix Emissions Rates (2019 Data)**

https://www.green-e.org/2021-residual-mix

- Residual mix rate emission factors used to calculate purchased electricity emission factors for scope 2 market-based method.

**EPA Waste Reduction Model (WARM)**

- Landfill emissions factors/sinks for CH4 and CO2; solid waste combustion for N2O;

**Solid Waste Management and Greenhouse Gases: A Life-Cycle Assessment of Emissions and Sinks**

https://nepis.epa.gov/Exe/ZyPURL.cgi?Dockey=60000AVO.TXT

- CO2e sink for compost

**Food reference details:**