Agriculture and Environment: Beef

Environmental Impacts of Production: Greenhouse Gas Emissions

Beef production has a considerable effect on global warming due to the emission of greenhouse gases such as methane, nitrous oxide, and carbon dioxide.

Methane is released from the cow's rumen and manure. Nitrous oxide is released from the soil by the microbial decomposition of manure and artificial fertilisers.

Carbon dioxide is released by direct energy consumption through mechanised feed crop production and the herding and movement of animals (the average beef calf sees more of the U.S. than the average cattle farmer).

Staggering amounts of methane released
Globally, ruminant livestock produce about 80 million metric tons of methane annually, accounting for about 22% of global methane emissions from human-related activities.

Cattle in the United States emit about 6 million metric tons of methane per year into the atmosphere. The cow/calf sector is the largest emitter of methane within the U.S. beef industry. It accounts for 54% of the total methane emissions from cattle, while the feedlots and stocker calves account for 21%, and dairy accounts for 25% (Ruminant Livestock Efficiency Program, 2002).

While cattle release huge quantities of methane into the environment, it is not clear that they produce more methane than similar wild animal populations did 200 years ago. Globally, however, as the number of cattle increases, it could well exceed historical levels of methane emitted by wild animals.