Meat and the Environment: Facts and resources

February 01, 2007

Facts on meat and the environment

Farm animals outweigh people
A meat-based diet requires 7 times more land
Farm animals naturally inefficient
Agriculture vs wilderness
Excessive use of energy & water
Livestock grazing
Fish – plundering the oceans
Facing food scarcity

PDF version: view as a two page 124k pdf file that can be printed.

Nov. 2006 news update
FAO: Livestock a major threat to environment

The United Nations Food & Agriculture Organization has issued a stunning report on global warming. Livestock production is responsible for more climate change gasses than all the motor vehicles in the world. In total, it is responsible for 18 percent of human induced greenhouse gas emissions. It is also a major source of land and water degradation.

Incredibly, 18 percent of global greenhouse gas emissions (as measured in carbon dioxide equivalent) are due to the growing numbers of livestock around the world. It’s not just methane and manure — land-use changes, especially deforestation to expand pastures and to create arable land for feed crops, is a big part. Emissions also arise from the energy used to produce fertilizers and pesticides for feed crops, run slaughterhouses, and pump water.

Livestock now use 30 percent of the earth’s entire land surface. In Latin America, 70 percent of former forests in the Amazon have been turned over to grazing. Animal waste accounts for 64 percent of ammonia, which contributes significantly to acid rain.

Livestock production is at the heart of almost every environmental catastrophe confronting the planet – rain forest destruction, spreading deserts, loss of fresh water, air and water pollution, acid rain and soil erosion.

Farm animals outweigh people

The world is experiencing a population explosion of farm animals. Between 1950 and 1994, global meat production increased nearly fourfold, rising faster than the human population. During this period, production rates jumped from 18 to 35.4 kilograms per person.1, 2 By 1994, the combined weight of the world’s 15 billion farm animals surpassed the weight of the human population by over one and a half times (see table below).

Overpopulation puts pressure on the earth’s resources. Each person has needs for food, water, shelter, heating/cooling and transportation. To a large extent domesticated animals have the same needs.

In United States, farm animals outweigh their human brethren by a factor of four to one, effectively making the US “population” balloon from 295 million to 1.2 billion.

In Canada, farm animals also outweigh people by a factor of four to one. On a given day there are approximately 14.6 million beef and dairy cattle, 13 million pigs, 8 million turkeys, 96 million chickens, and 30 million people alive in Canada.3Domesticated farm animals strain resources due to their increasing appetite for feed crops and grazing land.

Meat (excluding poultry) is the largest food industry in Canada with shipments of $9.5 billion in 1994, and is third largest overall, being surpassed only by the motor vehicle and oil industries.4

 [diagram showing that a meat-based diet requires 7 times more land than a plant-based diet.]
The average agricultural land area in North America is 1.4 hectares (3.5 acres) per person after adjusting for the export of grain. With a big cut in meat production, this area could easily be reduced to 0.2 hectares (half acre), the rate in many Asian countries. This huge savings in land could be used for reestablishing wilderness.

A meat-based diet requires 7 times more land than a plant-based diet.

The average agricultural land area in North America is 1.6 hectares per person (1.4 hectares after adjusting for the export of grain). Yet there are many countries in the world that use as little as 0.2 hectares (half acre) of farmland per person. These are the countries with plant-based diets.

An area equal to 0.2 hectares is the equivalent of having 5.5 square metres of land available to produce each day’s worth of food. The average yield worldwide, for cereal crops in 1994 was 2,814 kilograms per hectare, an amount equivalent to getting 1.5 kilograms (14 cups of cooked grain) per day from 0.2 hectares. For root crops the average global yield in that year would have provided 6.8 kilograms of food per day from 0.2 hectares.2

apple treesAnother example is the small footprint of land that fruit trees take up. A mature apple tree will produce about 20 bushels a year – enough for 400 pies. A fifth of a hectare (half acre) would yield enough fruit to provide about 115 apples per day.17 Tree crops also have the nice advantage of not being prone to soil erosion. In September 2008, I joined up with a Toronto group called Not Far From The Tree and went on a couple of pear picks. Just one tree yielded almost 1200 pears after a two hour pick. See photos and write-up at Delicious Earth.

Any country with reasonable growing conditions should be able to feed their population a plant-based diet using 0.2 hectares of land or less per person. Areas with harsh winter climates also have summers with long days of sunlight, ideal for producing high yields. Grains, legumes and roots can be easily stored for use during off seasons. Areas with regular dry seasons are often balanced with wet seasons.

Farm animals naturally inefficient

Farm animals are inefficient converters of plants to edible flesh. In 1993, US farm animals were fed 192.7 million tonnes of feed concentrates, the bulk of it corn, in order to produce 31.2 million tonnes of carcass meat – making for a ratio of 6.2 to 1. Additional feed was also provided in the form of roughage and pasture.5, 2 In terms of feed utilization, broiler chickens are the most efficient requiring 3.4 kilograms of feed (expressed in equivalent feeding value of corn) to produce one kilogram of ready-to-cook meat. Pigs are the least efficient, with a feed to meat ratio of 8.4 to 1. For eggs expressed as weight, the ratio is 3.8 to 1. For cheese the ratio is 7.9 to 1.5

Like us, animals are naturally inefficient because much of their food is converted into energy for movement, excreted as manure, or used for the growth of body parts not eaten by people. Very little can become direct edible weight gain. For example, cattle excrete 40 kilograms of manure for every kilogram of edible beef produced.6

The meat industry makes an effort to utilize some of the byproducts, but because of the huge numbers of animals slaughtered, this can be a challenge. Farmers prefer to use easy-to-spreadchemical fertilizers instead of trucking manure over long distances from factory-style animal farms (also know as confined animal feeding operations CAFO’s). On hog-raising operations in the U.S., only about one sixth of manure is utilized. Excess animal waste often ends up in rivers and groundwater where it contributes to nitrogen, phosphorus and nitrate pollution.7

Photo: Hog farms like this one in Georgia typically have large lagoons (see right side of photo) to collect animal waste.

In January 2006, the Environmental Protection Agency signed agreements that will let thousands of factory-style farms escape severe penalties for fouling the air and water with animal excrement in exchange for data to help curb future pollution. Over 2,600 animal feeding operations in the egg, chicken, turkey, dairy and hog industries will be exempt from having to pay potential fines of up to $27,500 a day for violations. Environmentalists plan to sue.7

In Canada, the stench from industrial pig farms has caused a huge problem for neighbours.

Meat that is unfit or unsuitable for human consumption is sold to the pet food industry, or processed and fed back to farm animals. Currently in Canada as much as 20% of cattle feed is made up of what is termed mammalian protein additives” and other animal waste products.8

Many countries are curtailing this practice in light of the rise of mad cow disease(BSE). In the U.K., the feeding of infected sheep to cattle has caused several cases of a deadly human dementia among beef consumers.

Agriculture vs wilderness

Devoting large amounts of land to feeding animals magnifies serious environmental problems associated with modern agriculture.

Each farm and pasture has a history of being a natural ecosystem of forest, wetlands or grassland. As wilderness is destroyed for agriculture, wild plants and animals are displaced – pushing many species to the brink of extinction. Twenty million hectares (50 million acres) of tropical forest in Latin America have been cut down for livestock production since 1970.7

Much of the prairies in central Canada have been lost to agriculture. Of the four principle ecoregions, less than 24% of mixed prairie, 30% of fescue prairie, 20% of aspen parkland and 1% of tall-grass prairie remain in a natural, undisturbed state. According to the Committee on the Status of Endangered Wildlife in Canada, the Black-footed Ferret and Prairie Swift Fox have become extirpated (extinct within a country) and 14 other prairie species are classified as endangered or threatened.9

Many ranchers rely on the services of the U.S. Department of Agriculture’s predator control program. According to USDA records, its Wildlife Services division shoots, poisons, traps or otherwise destroys about 80,000 coyotes a year on private and public lands nationwide.19

In dry areas, many farms depend on irrigation water that is pumped from limited aquifers (underground lakes) and dammed rivers. In Alberta most of the large rivers have been dammed for the main purpose of collecting water for irrigation. The cost of these dams are paid for with tax dollars.10

Farms tend to be treated with chemical fertilizers, herbicides and pesticides. In 1990, 64% of Canadian cropland was treated with commercial fertilizer and 55% was treated with herbicide.11 Pesticides can adversely affect non-target organisms such as birds and bees.

Erosion of precious topsoil from ploughed fields and over-grazed pastures is another serious agricultural problem. A permanent cover of vegetation is required to hold soil in place; once this is weakened or removed, soil can be easily washed or blown away by wind or rain. Soil mixed with agricultural chemicals and manure runs into streams and groundwater where it can cause extensive water pollution.

Organic farming can lessen some of the problems associated with agriculture – chemical dependency, erosion and pollution. But a shift in society toward plant-based diets would ease these problems simply by reducing the need for land.

Excessive use of energy

Animal foods demand the lion’s share of energy used in agriculture. According to one study, meat production requires 10 to 20 times more energy per edible tonne than grain production.6 Growing feed crops requires extensive energy for ploughing, harvesting, pumping irrigation water, transportation, and producing fertilizer and pesticides. Once grown, the crops are processed using additional energy. For instance, corn is heated in order to reduce its moisture content from 29% to 15%.12

Furthermore, the housing of pigs and chickens in huge windowless sheds requires energy for artificial ventilation, conveyor belts and electric lighting. Slaughterhouses are also energy and water intensive.

There is also the energy spent transporting farm animals at various points in their life cycle. According to a March 2006 report by the Humane Society of the U. S. “Before they are slaughtered, livestock travel an average of 1,000 miles, but some journeys are much longer. Long-distance transport not only increases the opportunities for animals to come into contact with – and to spread – diseases, but also increases their susceptibility to infection.”18

For harvesting fish, extensive energy and resources go into building, maintaining and fueling fleets of trawlers.

Finally, animal products tend to require more energy for processing, packaging and refrigeration than plant-based foods. In contrast, many vegetables, fruit, grains and tubers require no refrigeration and little or no processing.

Livestock grazing

Roughly one fifth of the world’s land area is used for grazing, twice the area used for growing crops.2 Much of this land was once wild grassland supporting a diverse range of plants, birds, rodents and wild grazing animals. Forests are also cleared for grazing. Central America has seen over one-third of its forests cut since the early 1960′s, while pasture land has increased by 50%.7

Grassland is often unsuited for cultivation, but with care it can generally be used sustainably for livestock grazing. Cattle, sheep and goats are ruminant animals that fare best on a diet of grass.

In dryland regions, cattle can overgraze perennial grasses, allowing annual weeds and shrubs to proliferate. The new weeds lack extensive root systems to guard soil against erosion. As the former diversity of plant species is lost, wildlife also declines.7According to a UN study titled “Global Assessment of Soil Degradation,” about 10.5% of the world’s fertile land suffers from moderate to extreme degradation. Overgrazing by livestock and current farming practices are the principle causes.13

Livestock displace natural grazing animals such as deer, antelope, bighorn sheep and bison. They also displace small animals and birds dependent on tall grasses for cover and nesting.  Encroaching networks of fences and roads are a further impediment to wildlife.

Fish – plundering the oceans

Since mid century, levels of fish consumption have risen dramatically, worldwide. The average harvest has gone from less than 9 kilograms per person in 1950 to more than 19 kilograms by 1989. To support the growing human population and increased demand for seafood, the global harvest more than quadrupled from 22 million tonnes to 100 million tonnes over the same period.1 Since 1989, increases in harvest levels have slowed to the point where they are just able to keep pace with the growth in human population.14

Current seafood harvest levels are so high that they are straining marine ecosystems in many areas. Of the 200 top marine fish resources in the world in 1994, about 35% were in decline and 25% were fully exploited.14

New York Times (free registration required) has an excellent multimedia feature called A Heavy Toll that shows images and movies on the effect of bottom trawling and overfishing on the world’s oceans and fish populations.

Aquaculture (farmed fish), which accounted for 17% of the world seafood harvest in 1994,14 has so far been making up for the decline in wild fish stocks. A tightening world grain supply may curtail growth as fish production requires large inputs of feed.

The world’s fishing industry is also causing harm to wildlife. Farming operations located along shorelines are made up of submerged floating cages. Disease pathogens can spread easily among the high densities of fish, and concentrated fecal wastes and drugs can contaminate adjacent waters. Fish that escape can spread disease and inbreeding to wild stocks. At least 140 distinct salmon stocks in British Columbia are already extinct.15

On the open seas, nets used to catch fish reel in a great number of non-targeted species including seabirds, turtles, seals and dolphins. Biologist Lee Alverson calculates that around 27 million tonnes of fish are wasted per year because they are the wrong kind or size. Shrimp boats that drag the bottom are the most wasteful, scooping up 10 kilograms of other marine life for every one kilogram of shrimp.16

See Fish & seafood – the environmental costs

Facing food scarcity

There are many indicators that the world is entering an era of declining food security. Available land for agriculture has peaked and is currently declining due to industrial and urban expansion and losses to degradation. Fresh water supplies for irrigation are getting scarcer and fertilizer use has just about reached its full potential.1 Fish production per capita has reached a plateau and may start to fall, while meat production from rangelands is in decline.

Between 1950 and 1984, world cereal crop yields increased by an average of 3% per year. Since 1984 yield increases have slowed to around 1% a year “ less than the amount needed to keep pace with population growth. The result has been a 7% decline in world cereal production per capita “ from a peak of 375 kilograms in 1984 to 349 kilograms in 1994.1

As the human population expands to nine billion hungry people in the coming decades, it is not hard to imagine every last forest, wetland and grassland being levelled for agriculture.

On existing farmland, methods used to increase yields are causing environmental problems. Rivers are being dammed for additional irrigation. Applications of pesticides, herbicides, and chemical fertilizers are being increased.

A shift in society toward plant-based diets would ease these problems simply by reducing livestock populations and their demand for land and other resources. On a per capita basis, the land requirements of countries with plant-based agricultural economies are only a fraction of the levels seen in countries with high meat production rates. Fewer animals to feed could lead to a rebuilding of world grain reserves, ensuring dependable supplies for direct human consumption in countries facing food scarcity.

In Canada, fewer animals to feed could free up land for conversion to wilderness. Wilderness is crucial for biological diversity, wildlife habitat, preventing soil erosion, climate control, and as a store for carbon dioxide. Natural ecosystems also clean the air and water of pollutants.


Eating low on the food chain is a powerful way to reduce the amount of land needed to support your existence (your ecological footprint). Less farmland means more wilderness. It also means less soil erosion, less dams, less pesticides and less energy use.

Plant-based cuisine is also healthy for the body. Numerous studies show that vegetarian foods greatly help in the prevention of heart disease, cancer and many other diet-related diseases.

As the earth’s human population continues to expand, two things are critical for our survival: adequate food resources and intact wilderness areas. One sure way to achieve both is a dramatic shift in food choices, away from animal products toward plant-based foods.

Excerpted from a paper presented at the 1997 International Conference on Sustainable Urban Food Systems, held at Ryerson University.

More information

Vegan Outreach
Environmental Impacts: Short footnoted article with lots of excellent photos, quotes and links.

Factory Farm Pollution
According to the Sierra Club, America’s drinking water, rivers and lakes are at risk from giant, corporate-owned factory farms. – Environmental Impact
“Instead of being eaten by people, the vast majority of grain harvested in the U.S. is fed to farm animals. This wasteful and inefficient practice has forced agribusiness to exploit vast stretches of land. Forests, wetlands, and other natural ecosystems and wildlife habitats have been decimated and turned into crop and grazing land. Scarce fossil fuels, groundwater, and topsoil resources which took millenniums to develop are now disappearing.
Meanwhile, the quantity of waste produced by farm animals in the U.S. is more than 130 times greater than that produced by humans. Agricultural runoff has killed millions of fish, and is the main reason why 60% of America’s rivers and streams are impaired.”

Factory Farm Alarm
Animal factories are laying waste to our environment and to public health according to EarthSave.


1. Lester Brown and Hal Kane, Full House: Reassessing the Earth’s Population Carrying Capacity (New York: Norton, 1994), pp. 31, 38, 76-77, 85, 95, 97, 186

2  FAOSTAT Statistics Database,” FAO Web Page (Food and Agriculture Organization of the United Nations (FAO), June 1997)

3. Statistics Canada:
Cattle and pig inventories are from 2001. Bird populations are from 2000 and have been adjusted for lifespan. Assumptions for average lifespan: broilers 6 1/2 weeks, layers one year, turkeys 20 weeks.

4 ”All About Canada’s Red Meat Industry.” Agriculture and agri-food in Canada fact sheet series (Agriculture Canada, October 1995).

 Agricultural Statistics 1997 (Washington, United States Department of Agriculture, 1997), Table 1-71, p. 8.
Note: Beware of inflated animal efficiency claims. For example the industry boasts that it takes only 2 kg of feed to produce 1 kg of chicken. This is for the whole weight of the animal “ even though only 72% of a chicken, 56% of a cow, and 58% of a pig is ready-to-cook meat.

6  Connections: Canadian Lifestyle Choices and the Environment.” A State of the Environment fact sheet. No 95-1 (Ottawa: Environment Canada, 1995), p. 7.

7  Alan Durning, and Holly Brough, Taking Stock: Animal Farming and the Environment (Washington: Worldwatch Institute, 1991), pp. 18-20, 25.

7b  EPA cuts deal with farms over animal waste Jan. 31, 2006.

8  Stephen Strauss, “Ottawa Acts To Reduce
Mad-Cow Disease Risk,” Globe and Mail 
(January 23, 1997), A1, A9

9  “The Praire Grasslands.” Fact sheet (Ottawa, Canadian Nature Federation. 1990)

10  Kevin Tighem, ”Last Ditch Effort,”Nature Canada, 20:2 (1991), pp. 40-45.

11 Trends and Highlights of Canadian Agriculture and its People, Catalogue No. 96-303E (Ottawa: Statistics Canada, 1991), p. 4.

12  “Agricultural Energy Research in Ontario: Part 2 Energy Efficiency and Conservation.” Highlights of Agricultural Research in Ontario, 8:3 (1985).

13  Associated Press, “Soil Deterioration Threatens World Food Supply,”Globe and Mail (April 3, 1992).

14 ”The State Of World Fisheries And Aquaculture 1996” FAO Web Page, (June 1997)

15  “Salmon Farming Industry Threatens BC’s Wild Fish Stocks,” press release(David Suzuki Foundation,, Oct.24, 1996); and Catherine Stewart, “Is Fish Farming the Solution?” Greenlink, 4:1(1996), pp.7,10.

16  Dan Westell,
“Fish Wasted on a Massive Scale,” Globe and Mail
(March 17, 1995), A8.

17  Apples & More , “Apple facts,” University of Illinois.
One tree produces an average of 20 bushels. One bushel contains about 120 apples (Allenberg’s Orchard 2004). 2400 apples from one tree amounts to 6.57/day. One acre can produce 700 bushels (Facts: All About Virginia Apples). 700 times 120 divided by 365 days equals 230 per acre or 115 apples per day from a half acre.Accessed Sept. 20, 2006.

18  An HSUS Report: Public Health Implications of Live Animal Transport.
Date Published: 03/10/06
Accessed Jan. 8. 2006.

19  Associated Press, Town’s coyote contest generates hoots, howls.
Date Published: 01/11/07
Accessed Jan. 14. 2007.