Beef: Environment - Greenhouse Gas Emissions

cow
 
cow

In 2006, the United Nations Food and Agriculture Organization (FAO) released a study revealing that the environmental damage caused by livestock surpasses the harm caused by all global transportation systems combined.1 Let’s break this damage down into three categories: greenhouse gas emissions, land use, and water concerns.

Greenhouse Gas Emissions
The United Nations Food and Agriculture Organization (FAO) found that livestock is responsible for nine percent of all carbon emissions, 37 percent of methane, and 65 percent of nitrous oxide.  Now, even though carbon dioxide emissions are the biggest and most discussed problem for the climate, methane is 23 times more damaging than CO2, and nitrous oxide has 296 times the warming potential of CO2.2 

It is critical to understand that the primary emission culprit in the livestock family—let alone the entire world’s food system—is beef.  A 1999 study found that each pound of feedlot produced beef creates 14.8 pounds of CO2 equivalent (meaning that other greenhouse gases are also taken into consideration), as compared to one pound of produced pork creating 3.8 pounds of CO2 equivalent, or one pound of chicken producing 1.1 pounds of CO2 equivalent.3

Mark Bittman, New York Times columnist and culinary hero to us here at New Dream, offers two great examples of comparisons that help illustrate how beef’s significant impact:

Gidon Eshel, a geophysicist at the Bard Center, and Pamela A. Martin, an assistant professor of geophysics at the University of Chicago, calculated that if Americans were to reduce meat consumption by just 20 percent it would be as if we all switched from a standard sedan — a Camry, say — to the ultra-efficient Prius. Similarly, a study last year by the National Institute of Livestock and Grassland Science in Japan estimated that 2.2 pounds of beef is responsible for the equivalent amount of carbon dioxide emitted by the average European car every 155 miles, and burns enough energy to light a 100-watt bulb for nearly 20 days. 4

What about beef makes it so polluting?  While the greenhouse gas impact of many other food categories has much to do with transportation from pasture to serving plate, only one percent of red meat’s emissions can be attributed to shipping.5   Beef’s high percentage of methane emissions and nitrous oxide, stemming from fertilizers used to grow the corn-based feed that challenges cows’ digestion, in addition to waste management by feedlot owners, and land cleared for grazing and growing feed  all contribute to beef’s significant footprint. 

It’s important to understand how a cow’s diet affects its greenhouse gas emissions.  There are two parts to this: 1) the footprint of the feed itself, 2) how the feed once eaten by the cows increases methane emissions.

Footnotes


1. Henning Steinfeld, Pierre Gerber, Tom Wassenaar, Vincent Castel, Mauricio Rosales, and Cees de Haan. Livestock’s Long Shadow. Food and Agriculture Organization of the United Nations. Rome, 2006.  xxi.


2. “Livestock a Major Threat to the Environment.” FAO Newsroom. United National Food and Agriculture Organization. 29 Nov 2006. .

3. Susan Subak. “Global Environmental Costs of Beef Production.” Ecological Economics. 30(1), 1999. 79-91.

4. Mark Bittman. “Rethinking the Meat Guzzler.” New York Times. 27 Jan 2008..

5. Rachel Ehrenberg. “It’s the Meat Not the Miles.” Science News. The Society for Science & the Public. 173(17), 24 May 2008.