Climate Change
Sources of Greenhouse Gas Emissions
- Overview
- Electricity
- Transportation
- Industry
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Commercial
& Residential - Agriculture
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Land Use
& Forestry
Agriculture Sector Emissions
Total U.S. Greenhouse Gas Emissions by Economic Sector in 2012
Total Emissions in 2012 = 6,526 Million Metric Tons of CO2 equivalent
*Land Use, Land-Use Change, and Forestry in the United States is a net sink and offsets approximately 15% of these greenhouse gas emissions.
All emission estimates from the Inventory of U.S. Greenhouse Gas Emissions and Sinks: 1990-2012.
Agricultural activities - the cultivation of crops and livestock for food - contribute to emissions in a variety of ways:
- Various management practices for agricultural soils can lead to production and emission of nitrous oxide (N2O). The large number of different activities that can contribute to N2O emissions from agricultural lands range from fertilizer application to methods of irrigation and tillage. Management of agricultural soils accounts for over half of the emissions from the Agriculture sector.*
- Livestock, especially cattle, produce methane (CH4) as part of their digestion. This process is called enteric fermentation, and it represents almost one third of the emissions from the Agriculture sector.
- The way in which manure from livestock is managed also contributes to CH4 and N2O emissions. Manure storage methods and the amount of exposure to oxygen and moisture can affect how these greenhouse gases are produced. Manure management accounts for about 13% of the total greenhouse gas emissions from the Agriculture sector in the United States.
- Smaller sources of emissions include rice cultivation, which produces CH4, and burning crop residues, which produce CH4 and N2O.
More national-level information about emissions from agriculture can be found in the agriculture chapter in the Inventory of U.S. Greenhouse Gas Emissions and Sinks.
*Management of agricultural soils can also lead to emissions of carbon dioxide (CO2). However, these emissions are included under the Land Use, Land-Use Change, and Forestry sector.
Emissions and Trends
In 2012, greenhouse gas emissions from agriculture accounted for approximately 9% of total U.S. greenhouse gas emissions. Greenhouse gas emissions from agriculture have increased by approximately 19% since 1990. One driver for this increase has been the 55% growth in combined CH4 and N2O emissions from livestock manure management systems, reflecting the increased use of emission-intensive liquid systems over this time period. Emissions from other agricultural sources have either remained flat or changed by a relatively small amount since 1990.
To learn about projected greenhouse gas emissions from the Agriculture sector to 2020, visit the U.S. Climate Action Report 2010 (PDF). (193 pp, 3.1 MB)
Greenhouse Gas Emissions from Agriculture
All emission estimates from the Inventory of U.S. Greenhouse Gas Emissions and Sinks: 1990-2012.
Reducing Emissions from Agriculture
The table shown below provides some examples of opportunities to reduce emissions from agriculture. For a more comprehensive list of options and a detailed assessment of how each option affects different gases, see Chapter 8 of the Contribution of Working Group III to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change
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| Type | How Emissions are Reduced | Examples |
|---|---|---|
| Land and Crop Management | Adjusting the methods for managing land and growing crops. |
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| Livestock Management | Adjusting feeding practices and other management methods to reduce the amount of CH4 resulting from enteric fermentation. | Improving pasture quality to increase animal productivity, which can reduce the amount of CH4 emitted per unit of animal product. Also, increased productivity can be accomplished through breeding. |
| Manure Management |
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