Sustainability of Land Use and Food Production
With the human population projected to increase by 50% to 8.8 billion by the year 2030, our ability to adequately feed everyone will face growing challenges1. Scaling back on heightened levels of resource-intensive meat production may be the best way to ensure food security for all.
Between 1950 and 1994, global meat production increased nearly fourfold, rising faster than the human population. The combined weight of the world's 15 billion farm animals now surpasses the weight of the human population by over one and a half times (see table below). The surfeit of farm animals strains resources and causes environmental harm due to the voracious appetites for feed crops and grazing land.
In many countries, the affluent are eating the most meat, often at the expense of poorer people dependent on grain supplies that are increasingly diverted to feeding livestock. Even in developing countries, meat production has been soaring; Indian poultry production has tripled since 1983, and Chinese grain consumption by livestock has increased five-fold since 1978.
How much farm land does one person need?
At Toronto's Royal Agricultural Winter Fair in 1992, a display presented two contrasting statistics: It takes four football fields of land (about 1.6 hectares) to feed each Canadian and One apple tree produces enough fruit to make 320 pies. If you think about it - a couple of apple trees and a few rows of wheat could produce enough food for one person on a mere fraction of a hectare!
No more than .2 hectares (half an acre) is needed to support somebody on a plant-based diet that includes very little, if any, meat; several of the countries listed in the table below are using close to this amount of land. With exports taken into account, North America uses seven times more land on a per capita basis than many countries in Asia, because large areas of land are used for grazing, and significant amounts of domestic grain supplies are fed to farm animals (see table).
Farm Animals Naturally Inefficient
Farm animals are extremely inefficient converters of plants to edible flesh. In 1993, US farm animals were fed 192.7 million tons of feed concentrates, the bulk of it corn, in order to produce 31.2 million tons of carcass meat - making for a ratio of 6.2 to 1 (additional feed was also provided in the form of roughage and pasture5 2). Broiler chickens require 3.4 kilograms of feed (expressed in equivalent feeding value of corn) to produce 1 kilogram of ready-to-cook chicken and pigs have a feed-to-meat ratio of 8.4 to 1. For eggs expressed as weight, the ratio is 3.8 to 1; for cheese it is 7.9 to 1.
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 produced6. Animal waste often ends up in rivers and groundwater, where it contributes to nitrogen, phosphorus and nitrate pollution.
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 products8. 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.
Excessive Energy and Water Usage
Land-intensive animal-based foods demand the lion's share of energy and water used in agriculture with meat production requiring 10 to 20 times more energy per edible ton than grain production6. Growing feed crops requires extensive energy for plowing, harvesting, pumping irrigation water, transportation, and producing fertilizers and pesticides, then additional energy for processing.
The housing of pigs and chickens in huge windowless sheds requires energy for artificial ventilation, conveyor belts and electric lighting. Slaughterhouses are energy- and water- intensive. For harvesting fish, much 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.
Roughly one fifth of the world's land area is used for grazing, twice the area used for growing crops2. Much of this land was once wild grassland supporting a diverse range of plants, birds, rodents and wild grazing animals. Grassland is often unsuited for cultivation, but with care it can generally be used sustainably for livestock grazing. Gains in grazing lands are often at the expense of wilderness areas. Over a third of the forests of Central America have been cut since the early sixties, while pasture land has increased by 50%7. In India, tiger reserves, national parks, and tree planting efforts are increasingly threatened by cattle and goats invading and eating young plant shoots.
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 declines7. According to a UN study, about 10.5% of the world's fertile land suffers from moderate to extreme degradation, with the principle causes being overgrazing by livestock and current farming practices13. Livestock displace natural grazing animals such as deer, antelope, bighorn sheep and bison, as well as small animals and birds dependent on tall grasses for cover and nesting.
Fish stocks running out
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; the global catch more than quadrupled from 22 million tons to 100 million tons1, straining marine ecosystems. Aquaculture, which accounted for 17% of the world seafood harvest in 1994, 17 has so far been making up for the decline in wild fish stocks, but a tightening world grain supply may curtail growth, since fish production requires large inputs of feed. Farmed fish yield about one kilogram of meat for every two kilograms of feed1. Biologist Lee Alverson, who has looked at 8,000 studies, calculates that around 27 million tons of fish are wasted per year because they are the wrong kind or size; shrimp boats, for example, scoop up 10 kilograms of other marine life for every one kilogram of shrimp.
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. 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 199420. As the human population expands to close 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.
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. 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. Reducing land use by cutting meat production is also a very effective method of ensuring that wilderness areas, crucial for diversity, climate control, and as a carbon dioxide store, can be maintained and even expanded.
Getting people to change entrenched eating habits is not easy. Although from the perspective of this analysis it may not be necessary to reduce meat consumption to zero, significant reductions may be required. 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.
This was edited from a paper that was presented at the 1997 International Conference on Sustainable Urban Food Systems, held at Ryerson University.
Footnotes (Hit "Back" on your browser to return)
1 Lester Brown and Hal Kane, Full House: Reassessing the Earth's Population Carrying Capacity (New York: Norton, 1994), pp. 31, 76-77, 85, 95
2 FAOSTAT Statistics Database," FAO Web Page (Food and Agriculture Organization of the United Nations (FAO), June 1997), Http://apps.fao.org/cgi-bin/nph-db.pl?subset=agriculture .
3 "All About Canada's Red Meat Industry." Agriculture and agri-food in Canada fact sheet series (Agriculture Canada, October 1995).
4 Neil Gardner, "Asia is Losing Ground," WorldWatch, 9:6 (1996), pp. 19-27.
5 Agricultural Statistics 1997 (Washington, United States Department of Agriculture, 1997), Table 1-71, p. 8.
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.
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 Maneka Gandhi, "Animal Welfare is Human Welfare." Resurgence, 175 (March/April 1996). pp. 16-20.
13 Associated Press, "Soil Deterioration Threatens World Food Supply," Globe and Mail (April 3, 1992).
16 From the preceeding of a hearing between the Thompson Watershed Coalition and Deputy Directory of the Wildlife Branch: Appeal No. 92/16 (Environmental Appeal Board, Province of British Columbia, April 22, 1993).
17 "The State Of World Fisheries And Aquaculture 1996 Summary,"FAO Web Page (Food and Agriculture Organization of the United Nations, June 1997), http://www.fao.org/waicent/faoinfo/fishery/publ/sofia/sofflye.htm
18 "Salmon Farming Industry Threatens BC's Wild Fish Stocks," press release (David Suzuki Foundation, October 24, 1996); and Catherine Stewart, "Is Fish Farming the Solution?" Greenlink, 4:1 (1996), pp. 7, 10.
19 Dan Westell, "Fish Wasted on a Massive Scale," Globe and Mail (March 17, 1995), A8.
20 Brown and Kane, Full House [note 1], pp. 31, 38, 97, 186.
Note: This is an abbreviated version of an article that originally appeared in the Toronto Vegetarian Association's Lifelines (v12#2, March-April 1998).