Greenhouse Gases
In 2013, total U.S. greenhouse gas emissions measured 6,673 million metric tons of carbon dioxide equivalents (MMT CO2 eq.), rising 5.9 percent from 1990 estimates from the EPA. 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 1750. Agriculture and forestry practices may either contribute to or remove GHGs from the atmosphere. Agriculture and forestry have contributed to GHGs in the atmosphere through cultivation and fertilization of soils, production of ruminant livestock, management of livestock manure, land use conversions, and fuel consumption. (Source: U.S. Agriculture and Forestry Greenhouse Gas Inventory: 1990-2013)
