Tuesday, December 7, 2010

Our dysfunctional food supply system: Part 2 - Factory Farming

Our seriously disordered food supply system is an enormous topic for discussion in terms of how it relates to our waistlines and our environment. I had originally set out to talk about two sub-themes. The first, our over-reliance on corn in food manufacturing, was discussed in October. Today I will talk about the second sub-theme: factory farming. 


It has been said that the way we eat has changed more in the last 50 years than in the previous 10,000 (1). The change from pasture-based to large-scale, intensive animal farming practices has, in large part, enabled us to eat the way we do now - satisfying our insatiable demand for cheap meat, and no doubt helping to grow our waistlines. According to the Food and Agriculture Organization of the United Nations (FAO), global production of animal source foods (including meat, milk and eggs) rapidly increased from 1960-2000 (2). This is considered to reflect the increasing demand for these types of foods. Even though global demand has increased, consumption, especially of meat, is more a function of wealth, such that demand does not reflect actual need. Not surprisingly, the U.S. is the second largest global consumer of meat (per capita), and Canada the 8th - both consume over 3 times the world average.  It is expected that global consumption of meat will continue to rise, as developing countries become more wealthy - by about 30% from 233 million metric tonnes (Mt) in 2000, to 300 million Mt  in 2020. Similar projections are estimated for milk and egg consumption.


FIGURE 1  Changes in meat production in developed and developing countries, 1960–2000.


In order for McDonald's to sell us cheap chicken nuggets and two-patty big-macs, the farm has become a factory where large numbers of animals are raised in close quarters - in feedlots, cages, crates, pens, stalls, and in warehouse-like facilities. Not only is this inhumane for the animals - devoid of natural stimuli and restrictive of innate behaviours - it is also energy inefficient and contributes substantially to global warming. 


The more obvious way in which factory farming contributes to green-house gas (GHG) emissions is through the enormous requirements for fossil fuels to grow crops, operate farm machinery, transport animals, and process and distribute animal-based food products. What might not be so obvious is the amount of manure that is generated. Often factory farms concentrate on farming just one thing, animals. Well then, what to do with all that poop? They have few or no fields to fertilize and too much poop to go around anyway. The result: large land areas that store massive amounts of manure. Some holding 'ponds' may be as large as 20 acres and 15 feet deep, containing 25 million gallons of manure(3,4)!  As these large land masses of manure decompose, they release huge amounts of methane, hydrogen sulfide, CO2, and ammonia into the atmosphere (5)(6). These holding areas are also prone to bursting and leaking, thus poop gets into our lakes and rivers.  Manure can also leach into surrounding water systems after being spread too excessively on crop fields (5). 


As you might have guessed this is not so good for the surrounding ecosystem, often resulting in fish kills and algal blooms (5). The quality of drinking water can also suffer. Decomposing algae can create an offensive taste and odour, and excessive nitrates can cause blue baby syndrome, a condition that reduces the baby's capacity to carry oxygen in the blood. And we know what can happen when our safeguards fail - you get the Walkerton tragedy. Plus, who wants to drink poop anyway?   



Overall, the agricultural sector contributed 8.5% of total GHG emissions in Canada during 2008. However, the agriculture sector is the second largest contributor to the long-term growth in GHG emissions, increasing 29% between 1990 and 2008 (6).  This was primarily the result of expansions in the beef cattle, swine, and poultry sectors, as well as an increase in the use of synthetic nitrogen fertilizers. When looking worldwide on the other hand, animal agriculture is estimated to contribute 18% of human-induced GHG emissions, which is surprisingly more than the transportation sector (7).   
    
I would like to go on as we haven't even begun to talk about other environmental effects of factory-farming such as excessive water use, deforestation, land degradation etc, and other potential health effects such as the propagation of swine flu.  Or how some scientists believe that intensive farming is actually good for the environment in terms of feeding the planet. As an aside to this argument, these scientists don't take into consideration the inequitable distribution of food worldwide - we already have far too much food, what we need to do is to reduce consumption in wealthy countries and provide basic needs for poorer countries = 'REDISTRIBUTION'! Alas, people lose interest in long posts so I will finish here by highlighting a statement made by the FAO from a landmark report:


“The livestock sector emerges as one of the top two or three most significant contributors to the most serious environmental problems, at every scale from local to global. The findings of this report suggest that it should be a major policy focus when dealing with problems of land degradation, climate change and air pollution, water shortage and water pollution, and loss of biodiversity”(7).



I would argue that what needs to be added to this statement is obesity.




References and Resources


(1) Food Inc. Script Dialogue - Michael Pollan. Available at: http://www.script-o-rama.com/movie_scripts/f/food-inc-script-transcript.html



(2) Speedy AW. Global Production and Consumption of Animal Source Foods. J Nutr. 2003; 133: 4048S–4053S, 2003. Available at: http://jn.nutrition.org/content/133/11/4048S.full.pdf+html


(3)Marvin D, (2005) Factory Farms Cause Pollution Increases. Johns Hopkins University Newsletter. Available at http://media.www.jhunewsletter.com/media/storage/paper932/news/2005/02/04/Science/Factory.Farms.Cause.Pollution.Increases-2243919.shtml 


(4) Schlosser E, Charles W (2006), Chew On This .Houghton Mifflin Company: New York.


(5) ManureNet: Environmental Issues http://agrienvarchive.ca/bioenergy/environ_issues.html 


(6) Environment Canada. National Inventory Report: 1990-2008 Part I. Greenhouse gas sources and sinks in Canada: The Canadian Government's Submission to the UN Framework Convention on Climate Change. Available at: http://www.ec.gc.ca/publications/492D914C-2EAB-47AB-A045-C62B2CDACC29/NationalInventoryReport19902008GreenhouseGasSourcesAndSinksInCanada.pdf


(7) Steinfeld H, Gerber P, Wassenaar T, Castel V, Rosales M, de Haan, C (2006). Livestock’s Long Shadow- Environmental Issues and Options. Food and Agriculture Organization of the United Nations. Available at: 
http://www.fao.org/docrep/010/a0701e/a0701e00.HTM