How Beef Stacks Up
It's clear from the EPA's methane estimates that the U.S. cattle industry contributes significantly to greenhouse gases. But how do beef and dairy products stack up pound for pound against other meats— and other foods?
EPA's methodology makes a pound-for-pound analysis difficult for a non-mathematician like me. Fortunately, a report prepared for the EIIP (Greenhouse Gas Committee Emissions Inventory Improvement Program), made available on a website by the State of Arizona, gives more useful calculations.
It's clear from both sources that methane emissions from cattle vary widely according to the animals' age and diet. The methane produced by cattle ranges from 104 pounds for a heifer, to 147 lbs/yr for mature beef cows, to 200 lbs/yr for mature beef bulls, to 269 lbs/yr for mature dairy cows.
An Iowa website suggests that the number of pounds of salable beef produced per cow per year (in the form of calves) is 490. Since it takes maintaining a cow-calf pair to produce a calf for beef, that 490 pounds of beef produces 251 pounds of methane (104 for the heifer plus 147 for the cow). That's 0.51 pounds of methane per pound of beef— a staggering 10.75 pounds of CO2 equivalence per pound of beef.
Dairy looks somewhat better: the average cow produces 2,000 gallons of milk per year (equivalent to roughly 2,200 pounds of cheese). That means dairy produces 1.54 pounds of CO2 equivalence per gallon of milk, or 1.28 pounds of CO2 equivalence per pound of cheese.
I wanted to compare these cattle-based foods with some other foods, calculated to the best of my ability (in pounds of CO2 equivalence). The calculations are not easy— the data, where available, is spread far and wide on the net, and occurs in differing units and contexts. Plus emissions vary according to climate and farming methods. Wheat, for example, typically produces a small amount of CO2 equivalence— but a study in Australia shows that it could be farmed in a way that absorbs more carbon than it produces. I'll do another post on the impact of farming methods at another time.
To make matters worse, CO2 equivalence for meat includes only enteric- and manure-based emissions— not the emissions generated by the feed the animal eats.
I've also tried to stick with scholarly and government sites, avoiding both pro- and anti-meat sources, as the figures they use vary significantly from each other and from the norm.
In the following table, I've attempted to deduce the direct and indirect emissions, in pounds of CO2 equivalence per pound of food, for some common staple foods based on typical factory farming methods and assuming a corn-based diet for livestock. Small producers would generally be somewhat less, as would any producer harvesting methane for fuel. Also, this does not include emissions from transportation to the retailer.
| Product | Production CO2 | Feed CO2 | Total CO2 Equivalence (lbs./lb.) |
| Rice | 276 | 276 | |
| Beef | 10.75 | 0.72 | 11.47 |
| Cheese | 1.28 | 0.36 | 1.64 |
| Pork | 0.56 | 0.63 | 1.19 |
| Turkey | 0.10 | 0.52 | 0.62 |
| Chicken | 0.17 | 0.36 | 0.53 |
| Eggs | 0.003 | 0.23 | 0.23 |
| Corn | 0.12 | 0.12 | |
| Soybeans | 0.04 | 0.04 | |
| Wheat | Negligible | Negligible | |
Clearly rice is the exception, thanks to its being grown in paddies where organic materials break down into methane throughout its crop cycle. Rice contributes 24 times more greenhouse gases to the environment than even beef. Still, this table suggests that America's beef habit is seven times more harmful to the environment than any food other than rice, and 250 times worse than soy.
On a scale of harm, wheat scores lowest, followed by soybeans, corn, and eggs. Non-ruminant meat sources come next, followed by dairy products. Compared to these, beef and rice are off the charts.
Once again, this does not incvlude transportation. Whether it's better to eat local dairy products or distant soy is a calculation for another day.
Sources: http://epa.gov/climatechange/emissions/downloads/08_Agriculture.pdf, http://www.ris.org.in/article2_v7n1.pdf, http://www.ethicurean.com/2007/03/18/rice-and-energy/, http://www.epa.gov/ttn/chief/ap42/ch09/draft/draftanimalfeed.pdf, http://www.straightdope.com/mailbag/mchickenegg.html, http://www.bcg.org.au/resources/GreenhouseGasEmissioninWimmeraMalleeCroppingSystems.pdf, http://csp.unl.edu/public/G_energy.htm, http://www.iowabeefcenter.org/content/Organic_Natural_Grass_Fed_Beef_2006.pdf, http://www.uaex.edu/Other_Areas/publications/PDF/FSA-4011.pdf, http://www.pork.org/newsandinformation/quickfacts/porkstory2.aspx, http://animalscience.ucdavis.edu/Avian/pfs16C.htm, http://www.georgiaeggs.org/pages/buying.html,
Trackbacks
-
7/6/2008 12:46 PM
www.AsymptoticLife.com wrote:
Sustainable Middle Class offers the graph above to show where U.S. corn goes. The results are startling: 46% goes to animal feed. 25% goes for ethanol production. 19% gets exported, mostly for animal feed in China and Japan. 6% becomes High Fructose Corn Syrup and other sweeteners. 2% becomes corn starch. 1.5% is eaten as cereal and other grain-based foods. 1% gets distilled for alcohol (presumably corn whiskeys) 1/5% is used as seed. In other words staggering two-thirds of the corn grown in the U.S. is used ... -
7/14/2009 5:05 PM
www.AsymptoticLife.com wrote:
(Tamaki photo.)I have received answers back from two experts on ricew and climate change. Dr. Reiner Wassman, scientist at the International Rice Research Institute, writes: "The proximate amount can be derived based on the IPCC guidelines (http://www.ipcc-nggip.iges.or.jp/public/2006gl/vol4.html):Emission of methane: 130 kg CH4/ ha/ season (assuming 100d cultivation period)= -
2/15/2009 10:54 PM
www.AsymptoticLife.com wrote:
(Nemo's great uncle photo: edamame (soybeans)).Yesterday, I noted that if we eliminated beef from our diet, we'd cut production-related emissions by over 720 pounds to about 123 pounds per year. That's a pretty significant reduction-- but it's possible to do better. If we eliminated meat and dairy from our diet completely and ate eggs and soy for protein, we'd reduce our footprint even further, to a total of about 25 pounds-- another 80% reduction over just giving up beef. Some may argue that eggs are an unnecessary extravagance, but at 0.23 pounds of CO2 per pound, they ... -
6/7/2008 7:41 AM
www.AsymptoticLife.com wrote:
The continuing effort to evaluate the eco-friendliness of various staple foods requires us to consider the effects of transportation. My primary question is, which is a better choice for protein foods: locally-produced dairy and eggs, or soy from distant places? Let's consider some sources of various types of protein: soy, eggs, cheese, chicken, and pork. So far as I know, there are no local sources of soy protein-- even our health food store doesn't stock any-- so I'll assume that soy comes from somewhere else, while the others are produced locally (in our case, with the ... -
6/6/2008 9:10 PM
www.AsymptoticLife.com wrote:
The continuing effort to evaluate the eco-friendliness of various staple foods requires us to consider the effects of transportation. The question in my mind is, which is a better choice for proteins: locally-produced dairy and eggs, or soy from distant places? Let's consider some sources of various types of protein: soy, eggs, cheese, chicken, and pork. So far as I know, there are no local sources of soy protein-- even our health food store doesn't stock any-- so I'll assume that soy comes from somewhere else, while the others are produced locally (in our case, with ...
Comments