The environmental toll of meat production – Carbon and other gas emissions

Current trends

Globally, world livestock currently uses approximately two-thirds of all available agricultural land.¹ Global meat production is on the rise. The fastest level of growth is in developing countries, as a product of population growth and increased income. At the same time, factory farms are the most rapidly growing avenues of meat production, and it appears that they represent the only form of meat production that can meet current and growing global demand levels.¹

Factory farms or concentrated animal feed operations (CAFOs) produce meat for the consumer at a very high rate. However, it is clear that this increased meat production also represents a threat to the global environment in terms of carbon emissions.

Sources of carbon emissions in meat production

Meat consumption relies on the meat production industry, which inevitably contributes to worldwide carbon emissions in several ways. One of these is the widespread use of fertilizer in grain crops used for feed. “In a sense, factory farms owe their existence to the advent of chemical fertilizer”.¹ The relatively large amount of feed that animals require makes this a serious concern.

Although the efficiency of farm animals at converting energy from their feed to edible flesh varies, all farm animals convert plants relatively inefficiently. For example, it is estimated that even after decades of effort at increasing efficiency, chickens raised to slaughter still consume from 5-11 kilogram of feed for every kilogram of weight they gain.¹ Because of this, the heavy use of fertilizers is needed to create the feed output required for farm animals.

Ammonia release is an issue as well. Due to recent pollution restrictions in Europe, many Dutch farmers relocated to the U.S.A., and since 2001, all 44 Dutch-owned farms have been cited for violation of air pollution regulations.¹ Other sources of carbon emissions from meat production include pesticide use associated with the grains fed to livestock, crop drying, field machinery use and maintenance, and irrigation of crop-producing fields.

There are further carbon emissions associated with the transportation of animals to slaughterhouses and rendering plants along with the increased power demands to run them, and the necessary refrigeration for meat products, which is generally not required for vegetables, fruits, and grains.² Finally, deforestation for the purposes of creating grazing land for livestock indirectly adds to carbon levels in the atmosphere. Forest systems that would have taken carbon out of the atmosphere are cleared to make room for farm animals to graze.

Examining the inefficiencies of meat production

Although it is difficult to calculate with perfect accuracy the effect of meat production and consumption on carbon emissions, there have been several studies that show some alarming data on this subject. According to a recent Japanese study, a cow’s total contribution to global warming throughout their life cycle is equal to 4550 kg of CO 2 equivalents.³ From the point of view of fossil fuels, there is a serious effect of eating meat.

Each consumer of the average American diet is calculated to be responsible for the equivalent in fossil fuels of driving an extra 17 kilometres per day.^{4, 5} It was estimated that farm livestock are responsible for approximately 18% of all globally released greenhouse gases. This represents a proportion of greenhouse emissions that is more than all forms of transportation combined!² Growing meat farms often come at the expense of wilderness with trees. As an indirect effect of meat farming, it is estimated that “livestock-related land use changes may emit 2.4 billion tonnes of CO 2 per year”.²

Solutions

Reducing or eliminating meat consumption can make a great deal of difference in reducing global warming. Recently, professors Gidon Eshel and Pamela Martin of the University of Chicago calculated that going vegetarian would eliminate 1.5 tons of CO 2-equivalent gases, per year.⁶

Related: For more on this issue also see our in depth article: Climate change: The inconvenient truth about what we eat.

References:

1. Danielle Nierenberg, Happier Meals, Rethinking the Global Meat Industry,
(Washington: Worldwatch Institute, 2005), pp. 5-24, 29, 62.
2. H. Steinfeld, P. Gerber, T. Wassenaar, V. Castel, M. Rosales, C. de Haan,
Livestock’s long shadow, Environmental issues and options, FAO, (2006),
http://www.virtualcentre.org/en/library/key_pub/longshad/A0701E00.htm
3. Akifumi Ogino, Hideki Orito, Kazuhiro Shimada, Hiroyuki Hirooka,
Evaluating environmental impacts of the Japanese beef cow–calf system by the life cycle assessment method, Animal Science Journal, 78(4): pp. 424-432, August 2007.
4. David Pimentel and Marcia Pimentel, Food, Energy, and Society
(University Press of Colorado, 1996).
5. “Bicycling Wastes Gas?”, Michael Bluejay,
http://bicycleuniverse.info/transpo/beef.html.
6. “Humans’ beef with livestock: a warmer planet”, Brad Knickerbocker,
Christian Science Monitor, February 20, 2007,
http://www.csmonitor.com/2007/0220/p03s01-ussc.html

Note: The above factsheet is available from Toronto Vegetarian Association as a printed page.