Thursday, March 29, 2007

Beef Not On The Menu For Environmentalists

Greenhouse gasses from cars, trucks,and busses are less than what results from animal agriculture.A United Nations Food and Agriculture Organization report published in 2006 points the finger at livestock operations globally. The study asserts that a 50% decrease must be achieved in order to avoid increasing the current level of environmental damage.

Animal farms around the world generate 18% more greenhouse emissions than all of the previously mentioned transportaion methods combined. Further, livestock production currently occupies 30 percent of earths land surface. The areas used for grazing are a major source of deforestation, particularly in Latin America, where 70% of former forest lands are used for grazing.

By far the most important non-CO2 greenhouse gas is methane, and the number one source of methane worldwide is animal agriculture.[1]
Methane is responsible for nearly as much global warming as all other non-CO2 greenhouse gases put together.[2] Methane is 21 times more powerful a greenhouse gas than CO2.[3] While atmospheric concentrations of CO2 have risen by about 31% since pre-industrial times, methane concentrations have more than doubled.[4] Whereas human sources of CO2 amount to just 3% of natural emissions, human sources produce one and a half times as much methane as all natural sources.[5] In fact, the effect of our methane emissions may be compounded as methane-induced warming in turn stimulates microbial decay of organic matter in wetlands—the primary natural source of methane.[6]
With methane emissions causing nearly half of the planet’s human-induced warming, methane reduction must be a priority. Methane is produced by a number of sources, including coal mining and landfills—but the number one source worldwide is animal agriculture.[7] Animal agriculture produces more than 100 million tons of methane a year.[8] And this source is on the rise: global meat consumption has increased fivefold in the past fifty years, and shows little sign of abating.[9] About 85% of this methane is produced in the digestive processes of livestock,[10] and while a single cow releases a relatively small amount of methane,[11] the collective effect on the environment of the hundreds of millions of livestock animals worldwide is enormous. An additional 15% of animal agricultural methane emissions are released from the massive “lagoons” used to store untreated farm animal waste,[1] and already a target of environmentalists’ for their role as the number one source of water pollution in the U.S.[13]
The conclusion is simple: arguably the best way to reduce global warming in our lifetimes is to reduce or eliminate our consumption of animal products. Simply by shifting to a plant-based diet[14][15][16] we can eliminate one of the major sources of emissions of methane, the greenhouse gas responsible for almost half of the global warming impacting the planet today.

1. Animal agriculture is also a major source of nitrous oxide emissions, another important greenhouse gas 310 times more powerful than carbon dioxide. 73% of U.S. emissions of nitrous oxide come from animal grazing, manure management, and crop growing practices—with half of U.S. crops grown for livestock feed. Agricultural emissions of nitrous oxide in the U.S. increased 9% from 1990 to 2002. “Inventory of U.S. Greenhouse Gas Emissions: 1990-2002,” EPA 430-R-04-003, U.S. Environmental Protection Agency, 15 April 2004, p. ES-16, emissions.
2. Hansen and Sato, supra note 11. Estimated climate forcing of methane from 1850 to 2000 is 0.7 W/m2, while estimated forcing of CFCs, tropospheric ozone, and nitrous oxide combined is 0.9 W/m2.
3. “Global Warming Potentials”, supra note 10.
4. Atmospheric CO2 concentrations have risen from 278 parts per million (ppm) in 1750 to 365 ppm in 1998. Atmospheric concentrations of methane have increased by 149% since 1750, from .700 ppm to 1.745 ppm. “Emissions of Greenhouse Gases in the United States 2002”, Chapter 1, Energy Information Administration, U.S. Department of Energy, October 2003,
5. Natural sources emit 770 billion metric tons of CO2, and 239 million metric tons of methane, compared to 23.1 billion and 359 million, respectively, for anthropogenic sources. “Emissions of Greenhouse Gases in the United States 2002”, supra note 20.
6. Hansen, et al, supra note 5. It is also possible that warming may dampen natural sources of methane by drying out wetlands.
7.Animal agriculture is responsible for 32% of global methane emissions from human activity, including 28% from domesticated livestock and 4% from livestock manure. Natural gas is the second largest source, accounting for 15% of emissions. Kruger, Dina, “The Role of ‘Other Gases’ in Addressing Climate Change”, U.S. Environmental Protection Agency, 12 Feb 2004, output_all/workshop/usjapan/pdf/06Kruger.pdf.
8. “Emissions of methane from livestock”, Climate Change Fact Sheet 32, Information Unit on Climate Change (IUCC), UNEP, 1 May 1993,
9. World meat production reached 242 million tons in 2002, from 122 million tons in 1977, and from 44 million tons in 1950. Additionally, per capita meat consumption has more than doubled since 1950, from 17 to 39 kg per person. Vital Signs 2003, Worldwatch Institute, May 2003, p.30-31, The majority of the meat is consumed by developed countries. Delgado, Christopher et al., Livestock to 2020: The Next Food Revolution, “Food, Agriculture, and the Environment Discussion Paper 28”, International Food Policy Research Institute, May 1999,
10. “The Role of ‘Other Gases’ in Addressing Climate Change”, supra note 23. Methane emissions come particularly from ruminant animals, like cows, sheep, buffalo, and goats, but also from non-ruminants like pigs and horses. “Emissions of methane from livestock”, supra note 24.
11.Not including methane released from manure, an adult cow produces 80-110 kg of methane a year. “Frequent Questions”, Ruminant Livestock, U.S. Environmental Protection Agency,
12.“The Role of ‘Other Gases’ in Addressing Climate Change”, supra note 23.
13.“Water Quality Conditions in the United States”, U.S. Environmental Protection Agency, August 2002,
14.Herein, the term “vegetarian” is used to refer not just to a meatless diet, but to one free of animal products, i.e. a “vegan” diet. Dairy cows, for example, produce even more methane per animal than beef cattle. Logically, the same concerns extend beyond diet to the consumption of other consumer goods derived from livestock, like wool and leather.
15.Because ruminant livestock produce far more methane than non-ruminant livestock, reductions in agricultural methane can also be achieved by shifting consumption away from cows and sheep in favor of chickens and pigs. However, the benefits of such shifts are not simple; for example, in the U.S., manure from pigs produces more than five times as much methane as manure from beef cattle. (“Inventory of U.S. Greenhouse Gas Emissions: 1990-2002”, p. 181, supra note 17.) Moreover, the large scale production of these animals in concentrated animal feeding operations (CAFOs) is associated with numerous other environmental harms already extensively documented by environmental organizations, making the trade of one environmental danger for another a Faustian bargain.
16.The U.S. Environmental Protection Agency’s efforts to address methane from livestock amount to encouraging changes in feed and increasing the amount of product (meat, milk, offspring) per animal. Even at best such efforts are unlikely to achieve large reductions in emissions per animal, and any such reductions are easily swamped by increases in the number of animals raised overall. Methane emissions from manure can also be captured and used to produce energy.

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