Air Pollution and Greenhouse Gas Emission Impacts

51% of all human-caused greenhouse gas emissions can be traced to animal agriculture and the meat and dairy industry. (WorldWatch, 2009)

The biomass of livestock today far exceeds the total biomass of all large land animals—wild, human or domestic—at any point in the past 100,000 years before the industrial revolution. (Harvesting the Biosphere: The Human Impact by Vaclav Smil)

Of all human-induced methane emissions, 37% comes from livestock. (Food & Agriculture Organization of the United Nations, FAO)

Livestock and their byproducts account for at least 32,000 million tons of carbon dioxide (CO2) every year. (WorldWatch, 2009)

Animal waste releases methane and nitrous oxide—greenhouse gases that are 25 and 300 times more potent than carbon dioxide (CO2), respectively. (Worldwatch Institute)

Methane has a global warming power 86 times that of CO2. (NASA, Jet Propulsion Laboratory)

Livestock is responsible for 65% of all emissions of nitrous oxide, a greenhouse gas 300 times more destructive than carbon dioxide and which stays in the atmosphere for 150 years. (Food & Agriculture Organization of the United Nations, FAO, 2006)

The burning of the world’s forests for cattle pastures has released billions of tons of CO₂ into the atmosphere. The world’s 1.3 billion cattle and other ruminant livestock emit 60 million tons of methane directly into the atmosphere each year, or 12 percent of all the methane released into the atmosphere. (mcspotlight.org)

The annual production of manure produced by animal confinement facilities exceed that produced by humans by at least three times. (EPA, 2007)

Emissions from the world’s livestock generates 65 percent of human-related nitrous oxide, which has 296 times the Global Warming Potential (GWP) of CO2. Most of this comes from manure. And it accounts for respectively 37 percent of all human-induced methane (23 times as warming as CO2), which is largely produced by the digestive system of ruminants, and 64 percent of ammonia, which contributes significantly to acid rain. (Food & Agriculture Organization of the United Nations, FAO)

Taking into account the production and distribution of 20 common agricultural products found that red meat such as beef and lamb is responsible for 10 to 40 times as many greenhouse gas emissions as common vegetables and grains. (Environmental Working Group, EWG)

Livestock are typically fed corn, soybean meal and other grains, which have to first be grown using large amounts of fertilizer, fossil fuel, pesticides, water and land. Estimate for growing feed for livestock in the U.S. alone requires 167 million pounds of pesticides and 17 billion pounds of nitrogen fertilizer every year across some 149 million acres of cropland. The process generates copious amounts of nitrous oxide, a greenhouse gas 300 times more potent than carbon dioxide (CO2), while the output of methane—another potent greenhouse gas—from cattle is estimated to generate some 20 percent of overall U.S. methane emissions. (Environmental Working Group, EWG)

Greenhouse gas emissions from all livestock operations, including IFAP facilities, account for 18 percent of all human-caused greenhouse gas emissions, exceeding the emissions caused from the entire U.S. transportation sector. (Steinfeld, 2006)

The ratio of fossil fuel energy inputs per unit of food energy produced averages 3:1 for all U.S. agricultural products combined. For industrially produced meat products, the ratio can be as high as 35:1 (beef produced in feedlots generally has a particularly unfavorable energy balance) (Horrigan, 2002)