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Effective beginning 5/20/2025: Please note this site is under review and content may change.

About

• About this Report
• Overview
• Errata
• Webinar Series
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Chapters

• Croplands and Grazing Lands
• Animal Production Systems
• Managed Forest Systems
• Managed Wetland Systems
• Land-Use Change
• Uncertainty

Recommended Citations

Hanson, W.L., C. Itle, K. Edquist (eds). 2024. Quantifying greenhouse gas fluxes in agriculture and forestry: Methods for entity-scale inventory. Technical Bulletin Number 1939, 2nd edition. Washington, DC: U.S. Department of Agriculture, Office of the Chief Economist.

About this Report

Section 2709 of the Food, Conservation, and Energy Act of 2008, directed USDA to "establish technical guidelines that outline science-based methods to measure the environmental service benefits from conservation and land management activities in order to facilitate the participation of farmers, ranchers, and forest landowners in emerging environmental services markets." The second edition of Quantifying Greenhouse Gas Fluxes in Agriculture and Forestry: Methods for Entity-Scale Inventory, published in 2024, represents the best available science-based methods for estimating greenhouse gas (GHG) emissions and removals from agricultural and forestry activities at the farm, ranch, and forest stand scale.

The first edition of Quantifying Greenhouse Gas Fluxes in Agriculture and Forestry: Methods for Entity-Scale Inventory was published in 2014 in response Section 2709 of the Food, Conservation, and Energy Act of 2008, which directed USDA to "establish technical guidelines that outline science-based methods to measure the environmental service benefits from conservation and land management activities in order to facilitate the participation of farmers, ranchers, and forest landowners in emerging environmental services markets." USDA has made substantial revisions in this second edition, published in 2024, ensuring the report continues to reflect the latest science-based methods for estimating greenhouse gas (GHG) emissions and removals from agricultural and forestry activities.

The second edition of this report is the result of four years of work by more than 60 authors, including USDA scientists, university researchers, and experts from non-government environmental organizations and research institutions, who have developed consistent metrics for estimating changes in GHG emissions and carbon sequestration for farm, ranch, and forest operations. The authors were chosen based on their experience with GHG inventories and accounting methodologies and their professional research experience. The authors worked in teams under the direction of one lead author for each team (plus one co-lead author for the forestry chapter).

Purpose

This report has several important purposes, including the following:

• Enabling landowners and others to estimate entity-scale GHG fluxes and impacts (including fluxes associated with different management practices) using the most accurate science-based methods currently available.
• Allowing USDA to estimate GHG fluxes from current and future conservation programs and practices and assess the performance of conservation and renewable energy programs using the most accurate science-based methods currently available given USDA's objectives and available resources. Note that this guidance does not explicitly address the intensity metrics of GHGs (i.e., emissions per production unit).
• Providing a basis for updating USDA's GHG flux estimation tools, including COMET-Planner and COMET-Farm.
• Informing GHG estimates for other programs. For example, this report may inform emerging methods that underlie voluntary GHG registries, facilitate regional GHG markets, and provide technical inputs for future GHG reporting programs.

USDA has made substantial revisions in this second edition of the report, published in 2024. These ensure the report continues to reflect the latest science-based methods for estimating GHG emissions and removals from agricultural and forestry activities. The second edition is the result of four years of work by more than 60 authors, including USDA scientists, university researchers, and experts from non-government environmental organizations and research institutions, who have developed consistent metrics for estimating changes in GHG emissions and carbon sequestration for farm, ranch, and forest operations. The authors were chosen based on their experience with GHG inventories and accounting methodologies and their professional research experience. The authors worked in teams under the direction of one lead author for each team (plus one co-lead author for the forestry chapter).

The updates to the report were reviewed by more than two dozen scientists, other Federal agencies, the public, and a panel of interdisciplinary experts to ensure they meet the criteria established by the White House Office of Management and Budget for the publication of a highly influential scientific assessment (HISA), a designation reserved for the most important science disseminated by the Federal Government. The HISA review of this report can be found on the Office of the Chief Economist's peer review website.

Additional Resources

For more information:

• Visit the Office of the Chief Economist
• Visit the Office of Energy and Environmental Policy
• Learn more about the Quantifying Greenhouse Gas Fluxes in Agriculture and Forestry: Methods for Entity-Scale Inventory project

You can also contact the USDA Office of Energy and Environmental Policy at sm.oce.methodsreport@usda.gov.