Scope 5 offers most of the EPA Hub emissions factors throughout its libraries. The Selected EPA Hub Tables library includes emissions factors for the following activities:
- Mobile Combustion
- Stationary Combustion
- Steam and Heat
Most of the emissions factors published by the EPA are included in various Scope 5 standard resource libraries. Below, we outline how the emissions factors are organized. Please note the EPA periodically renames table headings used to organize the emissions factors they publish. We update these Resource Sub-Categories to reflect the titles used in the most current release. Please contact us if you would like help mapping the organization of a resource throughout the EPA's updates.
The Selected EPA Hub Tables library includes the EPA eGRID emissions factors, sourced from Table 1, Total output emission rates, of the eGRID Summary Tables. This library includes factors through the EPA's February 2021 update.
EPA sub-regions have changed over the years. In order to maximize the utility of this library to Scope 5 users, we include all current sub-regions as well as the more recently published US Average and US Average (non-baseload) numbers. Sub-region unknown factors are no longer part of the GHG Protocol library. Puerto Rico was added in 2021 and its earliest-available emissions factor, effective in 2019, is also applied as the initial factor set.
For international electricity emissions factors, please see Scope 5 International Electricity Library.
The Selected EPA Hub Tables library includes emissions factors for Mobile Combustion CO2, Scope 3 Category 4: Upstream Transportation and Distribution and Category 9: Downstream Transportation and Distribution, and Scope 3 Category 6: Business Travel and Category 7: Employee Commuting.
If you are looking for Scope-1 mobile combustion resources that include an emissions factor for all component gases (CO2, CH4, N2O), we recommend reviewing the offerings in the Scope 5 TCR library. This library has a complete set of mobile combustion factors, which use the same underlying documents as the EPA Hub Tables.
Biogenic mobile combustion resources are considered 100% biogenic.
Mobile Combustion Activity Units
The emissions factors in the Business Travel & Employee Commute section and some of the emissions factors in the Upstream Transportation and Distribution and Downstream Transportation and Distribution section are expressed in units of distance (miles) in Scope 5. When applying them, please be aware that the EPA expresses them either in units of vehicle-miles or passenger-miles.
- A vehicle-mile is a unit of measurement that represents one vehicle traveling one mile. These are appropriate when the entire vehicle is dedicated to transporting the reporting company's product.
- A passenger-mile is a unit of measurement that represents one person traveling one mile in the public, shared mode of transport described by the resource. If two passengers travel the same distance together in the same mode of transport (for example, two employees take the same train trip), the activity entered into the tracker should reflect the total number of passenger miles, not the absolute distance traveled.
The remaining emissions factors in the Upstream Transportation and Distribution and Downstream Transportation and Distribution section are expressed in weight-distance. Weight-distance (such as ton-miles) is a specific type of unit associated with freight, in which activity expresses the product of the weight of the goods shipped and the distance over which they are shipped. Weight-distance activity is appropriate when the vehicle is shared with products from other companies.
The EPA gives the following examples and definitions for vehicle types:
- Passenger cars include "passenger cars, minivans, SUVs, and small pickup trucks (vehicles with wheelbase less than 121 inches)."
- Light-duty trucks include "full-size pickup trucks, full-size vans, and extended-length SUVs (vehicles with wheelbase greater than 121 inches)."
- Intercity rail includes "Amtrak long-distance rail between major cities. Northeast Corridor extends from Boston to Washington D.C. Other Routes are all routes outside the Northeast Corridor."
- Commuter rail includes "rail service between a central city and adjacent suburbs (also called regional rail or suburban rail)"
- Transit rail includes "rail typically within an urban center, such as subways, elevated railways, metropolitan railways (metro), streetcars, trolley cars, and tramways."
The Selected EPA Hub Tables library includes all emissions factors published in Table 1 of the EPA publication. Factors are available in units of energy and weight or volume, depending on the fuel type.
For all values by energy (for which the denominator is in MMBtu (or any energy unit)) Scope 5 has chosen to use the Higher Heat Value (HHV), as opposed to the Low Heating Value (LHV), to calculate the emissions factor. In GHG reporting the HHV is the more conservative value as it is always slightly higher or equivalent to the LHV, resulting is a slightly higher (or equivalent) emissions factor than would be calculated by using the LHV. Subsequent EPA releases have explicitly referenced only the HHV.
Biogenic stationary combustion resources are considered 100% biogenic.
Steam & Heat
Steam and Heat is included in the Selected EPA Hub Tables library.
The EPA's March 2020 update included waste factors based on version 15 of the EPA’s WARM tool. These factors are developed for use in GHG Inventories, specifically to quantify Scope 3 Category 5: Waste Generated in Operations and Category 12: End-of-Life Treatment of Sold Products activities.
These factors are categorized into six resource sub-types based on the waste disposal method:
- Anaerobically Digested (Wet) - where "Wet" stands for "Wet Digestate with Curing".
- Anaerobically Digested (Dry) - where "Dry" stands for "Wet Digestate with Curing".
Refrigerant Blends and Global Warming Potentials (GWPs)
Many of the EPA's Global Warming Potentials (GWPs) and GWPs for Blended Refrigerants (Tables 11 and 12), which use AR4 Global Warming Potentials, are incorporated into custom resource creation and can be selected as an impact. For AR5 GWPs for refrigerants and fugitive gasses, please see the Scope 5 Fugitive Emissions (AR5) library. Please contact us for further help.
Where the Numbers Come From
All factors in the Selected EPA Hub Tables library are sourced directly from the Center for Corporate Climate Leadership GHG Emission Factors Hub. Scope 5 includes the emissions factors from the November 2011, April 2014, November 2015, March 2018, March 2020 and April 2021 EPA publications.
A Note on Effective Dates
For the 2011-2018 updates, the effective date for each emissions factor set was sourced from the dates indicated by the Source data in the footnotes of the EPA tables when possible. For 2020 and subsequent updates, the first day of the publication year was used as the effective date. To learn more about the source data of each Conversion Factor Set, roll your cursor over the question mark icon in the library listing of Conversion Factors.
The EPA highlights any changes between versions in red text. For the 2011-2018 updates, Scope 5 added a new conversion factor set only to resources that changed between each of the EPA updates. Beginning with the 2020 update, a new conversion factor set is added to each resource to indicate it has been maintained.
Occasionally, in later publications, the EPA ceases to include resources it historically maintained. For example, the Methanol (CO2) (volume) Retired resource was included in the EPA's 2011 and 2014 release, but excluded thereafter. These resources include Retired as a suffix.
Global Warming Potentials (GWPs)
Following the Greenhouse Gas Protocol recommendation, all Scope 5 standard resource libraries use global warming potentials from the IPCC's Fifth Assessment Report (AR5) as of February 13, 2017. Please note the EPA recommends using AR4 GWPs.