Nitrogen References

Welcome to the nitrogen footprint references page! The nitrogen footprint includes N emissions in the form of NOx, N2O, and Other N. The calculation of the nitrogen footprint follows the guidelines from the GHG Protocol. Whenever possible, the same data sources are used for both the carbon and nitrogen footprint for alignment in methods and system bounds. For example, the EPA US GHG Inventory also includes NOx emissions because NOx is an important air quality pollutant and a precursor to greenhouse gases like ozone. In the links below, please find more details about the references, emission factors, and calculations for the nitrogen footprint. Additional details about the nitrogen footprint can be found on the Training page. As always, please contact us at with any questions.

General information on emission factor versions

2021 version of emission factors: Recommended

  • List of references used for the 2021 version of emission factors: Coming soon!
  • Table of all emission factor values for the 2021 version of emission factors: Coming soon!

2020 version of emission factors (outdated)

2019 version of emission factors (outdated)

2017 and 2018 versions of emission factors (outdated)