Can Animal Foods Be Produced Sustainably?

Can Animal Foods Be Produced Sustainably?

by David Simon

This article is from and is reprinted with the author’s permission.

At 200 pounds each per year, Americans eat more meat per capita than any other people in the world.

Unfortunately for the rest of the world, they’re catching up with us – and when they do, we’ll need two-thirds more land than exists on the planet to meet the higher demand.

sustainable meatThe world’s huge production of meat, eggs, fish and dairy is causing a head-on collision between demand for these items and the reality of scarce resources like land, water, and fossil fuels. This isn’t a future threat; it’s happening in real time, right now.

It takes up to 100 times more water, 11 times more fossil fuels, and 5 times more land to produce animal protein than equal amounts of plant protein.1

Further, animal food production is now the planet’s single biggest cause of climate change.2 The machinery of industrial farming is bursting at the seams, spilling animal emissions and production by-products across all environmental media—air, water, and land.

In this three-part series, I explore several popular ideas proposed to address the challenge of producing animal foods sustainably: local consumption, organic production, and fish farming. An in-depth look at these proposals seeks to answer the question: can animal foods be produced sustainably?

Part One: Loco for Local

Sustainability, some insist, requires that we consume food raised locally. Food’s carbon footprint is measured using a technique called “life cycle assessment” (LCA), which examines the carbon impact of every step or component in a food item’s production and consumption. LCA measures water use, harvesting methods, packaging materials, storage and preparation techniques, and other factors.

But spoiling the local food movement’s heavy emphasis on what it calls “food miles” is the fact that transportation averages only 11 percent of total carbon footprint and is thus a mere fraction of most edible items’ LCA. 3

By contrast, the act of cooking food typically accounts for 25 percent of its carbon footprint, while production accounts for another 17 percent of the carbon footprint.4 In other words, a modest efficiency or inefficiency in either production or cooking can easily outweigh transportation’s entire effect.


Dirk Vorderstraße, wikimedia commons

The LCA data lead to some startling conclusions about food miles and the merits of local consumption. For example, one study found that it’s more carbon friendly for the British to buy lamb from New Zealand than to buy locally.5 Lamb production is much more energy efficient in New Zealand than in the UK, in part because British production relies on fossil fuels while New Zealand production uses 64 percent renewable fuels.

Thus, British lamb production requires 45,859 megajoules (MJ) of energy per ton of meat, while New Zealand production takes only 8,588 MJ per ton. Even after adding in the 2,030 MJ of energy needed to ship the New Zealand meat to the UK, New Zealand is still the clear winner at only 10,618 MJ for both transport and production—less than one-quarter of the British production requirement. This difference in energy consumption means New Zealand also wins in CO2 output related to lamb production—just 688 kg/ton compared to the UK’s 2,849 kg/ton.6

In another example of Kiwi production efficiency, the same study found it’s more carbon friendly for Brits to buy their powdered milk from New Zealand instead of locally. New Zealand dairy cows are generally pastured and eat grass, while British cows are mostly confined and eat forage feed like hay and nutritional supplements known as concentrates.

The fuel inputs needed to produce the British cows’ forage feed and concentrates lead to major efficiency differences in milk production between the two countries.

dv1635026Thus, it takes 48,368 MJ of energy to produce a ton of powdered milk in the UK, but only 22,912 MJ in New Zealand. Even adding the 2,030 MJ necessary to transport the Kiwi powdered milk to the UK, the total energy used for both production and transport of the New Zealand product is 24,942 MJ—about half that in the UK.

Again, New Zealand’s lower energy use means less CO2 output: just 1,423 kg to produce and deliver a ton of powdered milk to the UK, versus the British emission of 2,921 kg of CO2 to produce the same ton of product.7

As these examples show, placing too much emphasis on food’s local origin can easily cause one to overlook LCA components that have a greater effect on the environment.

Such results led the New Zealand study’s authors to criticize the practice of equating food miles with carbon footprint—a practice they say “ignores the full energy and carbon emissions from production.”8

The moral here isn’t that we should completely ignore food miles in measuring food’s ecological impact; we just need to exercise more discretion in how much importance we give those miles. As Texas State University professor James McWilliams observes in his book Just Food:

Sure, it feels righteously green to buy a shiny apple at the local farmers’ market. But the savvy consumer must ask the inconvenient questions.

If the environment is dry, how much water had to be used to grow that apple? If it’s winter and the climate is cold, was the apple grown in an energy-hogging hothouse? Is the local fish I’m ordering being hunted to extinction? . . . Distance, in other words, is just a minor factor to consider.

In overemphasizing food miles, we have missed important opportunities to think more critically about the fuller complexities of food production.9

farmers-market-veggiesLocal consumption, then, is not the cure-all to solve the sustainability problems of meat and dairy production.

If you eat animal foods, to some extent you might help support small farmers by buying locally. But as we’ve seen, the carbon calculations are complicated, and local buying is often not the most eco-friendly way to consume. The only truly eco-friendly foods, of course, are plants.

Part Two: Organic Follies

Two acres of rain forest are cleared each minute to raise cattle or crops to feed them. 35,000 miles of American rivers are polluted with animal waste. In the mad race to the dinner plate, the scarce resources needed to produce meat, eggs, fish and dairy simply can’t keep pace with the demand for these foods.

Some commentators propose “green” alternatives like raising animals locally, organically, on pastures, or in fish farms. But it’s unclear whether these proposals are really viable or are just so much hot, greenhouse gas wafting into the sky.


This is the second installment in a three-part series which seeks to answer the question: can animal foods be produced sustainably?

In the first segment [above], we learned that determining the carbon effects of local consumption can be about as complex as planning a seven-course meal.

Simply put, locally raised animal foods can easily be less carbon-friendly than those from a distant continent, and local consumption thus does not make animal foods sustainable.

In the third segment, we learn that fish farming may not be the silver bullet of food production to feed the world sustainably. In this piece, we look at another key issue: whether farmed animals’ carbon footprint can be improved by raising them organically.

Manic for Organic

Is organic food really as good for the environment as we’d like to think?

Despite Prince Charles’s claim that organic farming provides “major benefits for wildlife and the wider environment,” a 2006 British government report found no evidence that the environmental impact of organic farming is better than that of conventional methods.10

In fact, because of large differences in land needs and growth characteristics between organic and inorganic animals, it’s hard to draw conclusions about the environmental benefits of one production method over the other.

As Table 1 below shows, considerably more land is required to produce organic animal foods than inorganic—in some cases more than double.

This higher land use is associated with higher emissions of harmful substances like ammonia, phosphate equivalents, and carbon dioxide equivalents.

Further, denied growth-promoting antibiotics, organic animals grow more slowly—which leads to higher energy use for organic poultry and eggs.

Thus, as Table 2 shows, when the overall effects of organic and inorganic animal production are compared, the results are notably mixed.

Table 1
Land Use Needs of Organic and Inorganic Animal Food Production (in acres)11

sustainable meat table

Table 2
Organic or Inorganic Production—Which Is Better for the Environment?12


O = Organic is better (based on lower use or emission)
I = Inorganic is better (based on lower use or emission)
N = No significant difference

We can see that poultry and eggs are mostly more eco-friendly when raised inorganically, while it’s generally more eco-friendly to raise pigs organically. As for cattle, factors like methane emissions and water use make the comparison more complicated.

Take methane. Besides figuring prominently in many a fart joke, it’s a highly potent greenhouse gas (although in its natural state, it’s actually odorless).

A single pound of it has the same heat-trapping properties as 21 pounds of carbon dioxide.13 Organic cattle must be grazed for part of their lives, which means that unlike feedlot cattle, they eat grass. However, cattle rely more on intestinal bacteria when digesting grass than grain, and this makes them more flatulent—and methane-productive—when eating grass.

The result is that grass-fed, organic cattle generate four times the methane that grain-fed, inorganic cattle do.14

Then there are the water issues. On a planet where water is not only the origin of all life but is also the key to its survival, animal agriculture siphons off a hugely disproportionate share of this increasingly scarce resource.

It can be hard to picture the quantities of water involved, so consider a few examples. The 4,000 gallons required to produce one hamburger is more than the average native of the Congo uses in a year.15

water required for meatAnd the 3 million gallons used to raise a single, half-ton beef steer would comfortably float a battleship.16

Pound for pound, it takes up to one hundred times more water to produce animal protein than grain protein.17 Organic cattle require 10 percent less water than inorganic but still need 2.7 million gallons each during their lives, enough to fill 130 residential swimming pools.

In light of the orders-of-magnitude difference in water needed to raise plant and animal protein, does a 10 percent savings for organic cattle really matter? Looked at another way, if Fred litters ten times a day while Mary litters only nine times, is Mary’s behavior really good for the environment? The value of such comparisons is dubious.

These factors lead to one conclusion: we must treat as highly suspect the claim that organic animal agriculture is sustainable. Organic methods are an environmentally-mixed bag—sometimes slightly better, sometimes a little worse, and often the same as inorganic.

But since animal protein takes many times the energy, water, and land to produce as plant protein, any modest gains from raising animals organically are largely irrelevant.18

Shocked that organic production isn’t the silver bullet of sustainability? For more surprising information on this and other issues related to animal food production, check out my just-released book, Meatonomics: How the Rigged Economics of Meat and Dairy Make You Consume Too Much – and How to Eat Better, Live Longer, and Spend Smarter (Conari Press, 2013).


1. David Robinson Simon, Meatonomics: How the Rigged Economics of Meat and Dairy Make You Consume Too Much—and How to Eat Better, Live Longer, and Spend Smarter (San Francisco: Conari Press, 2013).

2. Robert Goodland and Jeff Anhang, “Livestock and Climate Change: What if the Key Actors in Climate Change Are . . . Cows, Pigs and Chickens?” World Watch (November/December 2009): 10–19.

3. Christopher L. Weber and H. Scott Matthews, “Food-Miles and the Relative Climate Impacts of Food Choices in the United States,” Environmental Science and Technology 42, no. 10 (2008): 3508–13.

4. Rich Pirog et al., “Food, Fuel, and Freeways: An Iowa Perspective on How Far Food Travels, Fuel Usage, and Greenhouse Gas Emissions,” Leopold Center for Sustainable Agriculture (2001).

5. Caroline Saunders and Andrew Barber, “Carbon Footprints, Life Cycle Analysis, Food Miles: Global Trade Trends and Market Issues,” Political Science 60, no. 1 (2008): 73–88.

6. Ibid.

7. Ibid.

8. Ibid, 87.

9. James McWilliams, Just Food: Where Locavores Get It Wrong and How We Can Eat Responsibly (New York: Back Bay Books, 2009), 214.

10. C. Foster et al., “Environmental Impacts of Food Production and Consumption: A Report to the Department for Environment Food and Rural Affairs,” Eldis (2006).

11. Data expressed in hectares converted to acres. A. G. Williams, E. Audsley, and D. L. Sandars, “Determining the Environmental Burdens and Resource Use in the Production of Agricultural and Horticultural Commodities” (2006), Main Report, UK Department of Environment, Food, and Rural Affairs Research Project IS0205.

12. Williams, Audsley, and Sandars, “Environmental Burdens in Production of Agricultural Commodities”; David Pimentel and Marcia Pimentel, Food, Energy, and Society, (Niwot, CO: Colorado University Press, 1996).

13. US Environmental Protection Agency, “Methane: Science” (2010).

14. L. A. Harper et al., “Direct Measurements of Methane Emissions from Grazing and Feedlot Cattle,” 77, no. 6 (1999): 1392–1401.

15. ChartsBin, “Total Water Use per Capita by Country,” accessed December 23, 2012,

16. Assuming the animal weighs 1,200 pounds; metric units converted to imperial. T. Oki et al., “Virtual Water Trade to Japan and in the World” (presentation, International Expert Meeting on Virtual Water Trade, Netherlands, 2003).

17. Pimentel and Pimentel, Food, Energy and Society.

18. David Pimentel and Marcia Pimentel, “Sustainability of Meat-Based and Plant-Based Diets and the Environment,” American Clinical Journal of Nutrition 78, no. (3) (2003): 6605–-35.