Emission Factors and Global Warming Potentials

The greenhouse gas emission factors and global warming potentials (GWPs) presented on this page should be used for preparing emission inventories and calculating emission reductions submitted to EIA on Form EIA-1605(b).

• Fuel and Energy Emission Factors: Instructions | Tables
• Electricity Emission Factors: Instructions | Tables
• EPA’s AP-42 Emission Factors: Instructions | Tables
• Global Warming Potentials (GWPs): Instructions | Tables

Emission Factors

Fuel and Energy Emission Factors: Use these factors to estimate carbon dioxide emissions and emission reductions associated with fuel consumption by stationary and mobile sources.

• Fuel Emission Factors
• Emission Benchmarks for Purchased Steam and Chilled/Hot Water

Domestic and Foreign Electricity Emission Factors: Use the regional electricity factors to estimate emission reductions associated with electricity generation and consumption as follows:

• Use 1999-2002 factors to calculate emissions and reductions for Start Year reports for 2002 or later and Reporting Year reports for 2003 or later.

• Use 1991-1994 factors to calculate emissions and reductions for Start Year reports for 1990 through 2001 and Reporting Year reports for 1991 through 2001.

• Use Emission Inventory factors to estimate indirect emissions from the consumption of purchased electricity. The Emission Inventory factors represent the weighted average emissions including transmission and distribution losses for state-based regions for the given time period for electricity generated from all sources in the geographic region or country indicated.

• Emission Reductions/Avoided Emissions factors as benchmark values for calculating emission reductions associated with the generation of electricity that displaces power from higher-emitting sources in Addendum B methods B1, B2, B4, B5, B6, B7, B9, B10, B11, and B14. The Emission Reductions/Avoided Emissions factors represent the weighted average emissions excluding transmission and distribution losses for state-based regions for the given time period for electricity generated by fossil fuel-fired sources in the geographic region or country indicated.

• Emission Reductions/Indirect Emissions factors to estimate reductions from the consumption of purchased electricity. The Emission Reductions/Indirect Emissions factors represent the weighted average emissions including transmission and distribution losses for state-based regions for the given time period for electricity generated by fossil fuel-fired sources in the geographic region or country indicated.

• Domestic factors for electricity generated or consumed in the United States and its territories. U.S. Average electricity factors are provided for situations where electricity consumption or generation cannot be disaggregated (e.g., Addendum B9).

• Foreign electricity factors for electricity consumed or generated in foreign countries. Regional electricity emission factors are provided for entities reporting aggregated emissions and reduction from foreign sources.

• Domestic and Foreign Electricity Emission Factors (All)

• Domestic Electricity Emission Factors by Region, 1999-2002

• Domestic Electricity Emission Factors by Region, 1991-1994

• International Electricity Emission Factors by Country, 1999-2002

• International Electricity Emission Factors by Country, 1991-1994

EPA’s AP-42 Emission Factors: The Technical Guidelines permit or require the use of other emission factors for certain emissions or reductions calculations. Use the links below to view EPA’s AP-42 Emission Factors.

• AP-42 Volume 1 stationary point and area sources
• AP-42 Volume 2 mobile sources

Global Warming Potentials

The Intergovernmental Panel on Climate Change (IPCC) revised GWPs for certain greenhouse gases in 2007 for the Fourth Assessment Report (AR4). Reporters should use the AR4 GWPs to convert emission quantities to carbon dioxide equivalent (CO₂e) where available. Reporters should use Third Assessment Report (TAR) GWPs for gases for which the IPCC did not estimate revised GWPs for the AR4.

• Global Warming Potentials: TAR and AR4 GWPs for carbon dioxide, methane, nitrous oxide, HFCs, PFCs, and sulfur hexafluoride.