Author
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Del Grosso, Stephen - Steve |
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BARANSKI, MARCI - Office Of The Chief Economist |
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Submitted to: Government Publication/Report
Publication Type: Government Publication Publication Acceptance Date: 5/2/2016 Publication Date: N/A Citation: N/A Interpretive Summary: Global concentrations of the three most important long-lived greenhouse gases (GHG) in the atmosphere have increased measurably since the onset of the Industrial revolution. In 2013, total U.S. greenhouse gas emissions were 6,673 million metric tons of carbon dioxide equivalents (MMT CO2 eq.), rising 5.9 percent from 1990 estimates. Agriculture and forestry practices may either contribute to or remove GHG from the atmosphere. Agriculture and forestry have contributed to GHG levels in the atmosphere through cultivation and fertilization of soils, production of ruminant livestock, management of livestock manure, land use conversions, and fuel consumption. The primary GHG sources for agriculture are nitrous oxide (N2O) emissions from cropped and grazed soils, methane (CH4) emissions from ruminant livestock production and rice cultivation, and CH4 and N2O emissions from managed livestock waste. The management of cropped, grazed, and forestland has helped offset GHG emissions by promoting the biological uptake of carbon dioxide (CO2) through the incorporation of carbon into biomass, wood products, and soils, yielding a U.S.net emissions of 5,803 MMT CO2 eq. Net emissions equate to total greenhouse gas emissions minus CO2 sequestration in growing forests, wood products, and soils. This report serves to estimate U.S. GHG emissions for the agricultural sector, to quantify uncertainty in emission estimates, and to estimate the potential of agriculture to mitigate U.S. GHG emissions. Technical Abstract: Carbon dioxide (CO2), methane (CH4), and nitrous oxide (N2O) concentrations in the atmosphere have increased by approximately 43%, 152%, and 20% respectively since about 1750. In 2013, total U.S. greenhouse gas emissions were 6,673 million metric tons of carbon dioxide equivalents (MMT CO2 eq.), rising 5.9 percent from 1990 estimates. Agriculture and forestry practices may either contribute to or remove GHG from the atmosphere. Agriculture and forestry have contributed to GHG levels in the atmosphere through cultivation and fertilization of soils, production of ruminant livestock, management of livestock manure, land use conversions, and fuel consumption. The primary GHG sources for agriculture are N2O emissions from cropped and grazed soils, CH4 emissions from ruminant livestock production and rice cultivation, and CH4 and N2O emissions from managed livestock waste. The management of cropped, grazed, and forestland has helped offset GHG emissions by promoting the biological uptake of CO2 through the incorporation of carbon into biomass, wood products, and soils, yielding a U.S.net emissions of 5,803 MMT CO2 eq. Net emissions equate to total greenhouse gas emissions minus CO2 sequestration or removal of CO2 from the atmosphere including the net forest sink as well as the net soil sink from grazed lands and croplands. This report serves to estimate U.S. GHG emissions for the agricultural sector, to quantify uncertainty in emission estimates, and to estimate the potential of agriculture to mitigate U.S. GHG emissions. |
