There are ii chief avenues in which raising cattle leads to greenhouse gas emissions: ane. The cattle themselves release methyl hydride into the atmosphere 2. Producing & transporting feed for the cattle

Cattle Methane Production Through Digestion Equally cattle digest their food (grain or grass), their ruminant digestive systems produce methane, a greenhouse gas.  Cattle release this marsh gas primarily past belching, though also to a lesser extent through flatulence.

Studies accept shown that grass-fed cattle produce 20% more methyl hydride in their lifetime than grain-fed cattle.  This is due to ii unlike factors:

one) cattle naturally emit more than methane when digesting grass. 2) grass-fed cattle reach marketplace weight more slowly than feedlot cattle, so they're emitting methane over a longer time (Marshall, 2010).

Still, the above percentage may exist misleading (from a carbon footprint standpoint) due to a phenomenon known every bit "carbon sequestration."

Grass-Fed Cattle & Carbon Sequestration Grass-fed cattle may mitigate these increased emissions through carbon sequestration. Cattle rotated beyond pasture state encourage new growth while working manure and other natural fertilizers into the soil.

The theory is that good for you soil traps carbon dioxide, keeping it from rising into the temper. "Indeed, although grass-fed cattle may produce more than methane than conventional ones…their cyberspace emissions are lower considering they help the soil sequester carbon" (Abend, 2010).

Cattle Greenhouse Gasses Due to Grain Feed Production & Transport Look at the ecology costs of producing feed though, and there'southward really no contest.  Grass-fed cattle, despite their increased methane production, represent significantly less greenhouse gasses.

The Environmental Price of Corn Cattle pasture-raised in a mild climate with rotation between pastures consume food that represents very piffling greenhouse gas emissions.  "Grasses are perennials…that means they grow back year after year and there'southward not a lot of fuel used to produce the grasses." (Gellerman, 2008)

In contrast, the grain (corn) fed to feedlot cattle represents a huge output of fossil-fuel energy.  As Michael Pollan (The Omnivores Dilemma) explains: "Much of the carbon footprint of beef comes from growing grain to feed the animals, which requires fossil-fuel-based fertilizers, pesticides, transportation" (Abend, 2010).

Greenhouse gas emissions for all elements of crop producti accept been estimated to vary between 226-426 kilograms of carbon dioxide equivalent2 per metric ton of corn (Adam J. Liska, 2009).  That means each pound of corn is responsible for .23lb – .43lb CO2 equivalent greenhouse gasses.

The Feed Emissions Per Caput of Cattle The percentage of corn in cattle feed can vary from feedlot to feedlot, but co-ordinate to the industry, cattle gain 2.v-4lbs per 24-hour interval on feedlots at a rate of roughly 1lb gained per 6lbs of feed.  They also say feed contains an boilerplate of 70-90% grain across the industry (The National Cattlemen's Beef Association) though they aren't clear how much of that is corn.

From these numbers nosotros can judge that the average animate being consumes fifteen-24lbs of feed per day.  Bold that at least 70% of that is corn, 2.4-vii.2lbs of carbon is released from feed production alone per animal per mean solar day.

The manufacture says that cattle are usually feedlot finished for an boilerplate of three to half-dozen months (The National Cattlemen'due south Beef Association).  Based on the "best-case scenario" (an creature eating the minimum feed for the minimum amount of fourth dimension), the emissions from feeding one animal 15lbs of 70% corn feed for three months are around 201.6lbs of carbon.

How Much Carbon is That? To put this in perspective, "a medium growth coniferous tree, planted in an urban setting and allowed to abound for 10 years, sequesters 23.3lbs of carbon." (Environmental Protection Agency, 2011).  To starting time only the feedlot feed of this "all-time-case" animal, you demand to found 9 trees that alive for at least x years.

33.5 million head of cattle were harvested in the US in 2011 (National Cattlemen'south Beef Association).  Grass-fed beefiness may correspond 3% or less of all U.S. beef sales (Cross, 2011). If 32,495,000 of those cattle were fed corn according to the "best instance" example above, we'd need to plant at least 292,455,000 copse (living 10 years) to offset the feedlot corn from i year's worth American grain-fed beefiness.

Silverish Fern cattle are raised on pastures year-round and are grass-fed and finished.

1 Fertilizer utilize & production, lime, herbicides, insecticides, seed, gasoline used, diesel, liquefied gas, electricity, depreciable capital, N2O emissions. two Standard greenhouse gas measurement method – an aggregate of all greenhouse gasses emitted, with quantity weighted based on greenhouse affect of the diverse grasses relative to CO2 (for example, Nitrogen has more than effect than CO2, others have less upshot than C02)

Works Cited Abend, L. (2010, January 25). How Cows (Grass-Fed Simply) Could Relieve the Planet. Retrieved July xi, 2011, from Time Magazine: http://www.fourth dimension.com/time/magazine/article/0,9171,1953692,00.html

Adam J. Liska, H. S. (2009, Jan 21). Improvements in Life Cycle Free energy Efficiency and Greenhouse Gas Emissions of Corn-Ethanol. Retrieved December 22, 2011, from DigitalCommons @ University of Nebraska – Lincoln: http://digitalcommons.unl.edu/cgi/viewcontent.cgi?article=thou&context=ncesrpub

Cross, K. (2011, March 29). The grass-fed vs. grain-fed beef debate. Retrieved December 27, 2011, from CNN.com: http://www.cnn.com/2011/HEALTH/03/29/grass.grain.beef.cookinglight/alphabetize.html

Environmental Protection Agency. (2011, November 1). Calculations and References. Retrieved December 27, 2011, from U.s. Environmental Protection Agency: http://www.epa.gov/cleanenergy/energy-resources/refs.html

Gellerman, B. (2008, February 8). Math on the Range. Retrieved July xi, 2011, from Living on Earth: http://www.loe.org/shows/segments.html?programID=08-P13-00006&segmentID=iv

Marshall, J. (2010, Jan 27). Grass-Fed Beef Has Bigger Carbon Footprint. Retrieved July 11, 2011, from Discovery News: http://news.discovery.com/earth/grass-fed-beef-grain.html

National Cattlemen'south Beefiness Association. (n.d.). Beef Industry Statistics. Retrieved December 27, 2011, from Beef Usa – National Cattlemen'southward Beef Association: http://www.beefusa.org/beefindustrystatistics.aspx

The National Cattlemen's Beef Association. (northward.d.). Fact Canvass: Feedlot Finishing Cattle. Retrieved December 27, 2011, from Beefiness The states – National Cattlemen's Beef Clan: http://www.beefusa.org/uDocs/Feedlot%20finishing%20fact%20sheet%20FINAL_4%2026%2006.pdf