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Environmental Impact of the US Food System



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  • Lal, R., and Stewart, B. (1990). Soil Degradation. Springer-Verlag, New York.


  • 1. The Environmental Impact of the US Food System By Rob Abrams For ECO-177
  • 2. Outline I. Subsides II. Monoculture Soil depletion and erosion Water contamination III. GMOs Environmental benefits Environmental risks IV. Greenhouse gas emissions V. What can we do?
  • 4. SUBSIDIES • Farm Bill created during the Great Depression • Designed to compensate farmers during a period of excess supply • Renewed about every 5 years under various names • Current farm bill includes food assistance programs
  • 5. Current Bill (2014 – 2023) • As you can see, most of the modern farm bill is based around food assistance. But that’s another presentation… gs/wonkblog/wp/2014/01/28/the- 950-billion-farm-bill-in-one-chart/
  • 6. Farm Bill • 10% of farms received 75% of subsidies1 • Top subsidized crops between1995- 2012 are1 : • Corn: $84.4 billion • Wheat: $35.5 billion • Cotton: $32.8 billion • Soybean: 27.8 billion • (Note the lack of vegetables. But that’s another presentation…)
  • 7. Farm Bill • Farm Bill subsidies have made production of those crops listed on the previous slide extremely profitable • This encourages large corporate farms to grow vast quantities of the same crops on the same land year after year in a practice called monocropping or monoculture.
  • 9. Monoculture • Monoculture relies on massive amounts of artificial fertilizers to replenish soil year after year • More pesticides and herbicides are also required than “traditional” farming techniques as monoculture fields are not as resilient • Leaves soil susceptible to erosion • Biodiversity of the surrounding ecosystem can be severely affected
  • 10. MONOCULTURE CONSEQUENCES Soil Depletion and Erosion
  • 11. Soil Depletion and Erosion • Corn, wheat, and soybean monocultures require fertilizer, especially nitrogen because they are not rotated with nitrogen-fixing crops • 40% of all energy used in agriculture goes towards fertilizer and pesticide production2 • Production and mining of nitrogen fertilizer results in a significant amount of greenhouse gas release3
  • 12. Soil Depletion and Erosion • Every year worldwide, about 12 billion hectares of farmable land is overused and abandoned because of unsustainable farming practices4 • In 2007, 1.73 billion tons of topsoil was lost due to erosion in the US7 • This amounts to 200,000 tons per hour
  • 13. Soil Depletion and Erosion • Excess artificial fertilizers can result in trace mineral depletion in soil • This causes the land to produce crops that are lacking in minerals such as zinc, copper and manganese
  • 14. Soil Depletion and Erosion • It is estimated that annually, 2.5 billion dollars worth of excess fertilizer (that is, more than the crops could ever use) is applied every year5 • All of these excess nutrients have to go somewhere…
  • 15. Soil Depletion and Erosion •is estimated that annually, 2.5 billion dollars worth of excess fertilizer (that is, more than the crops could ever use) is applied every year5 • All of these excess nutrients have to go somewhere… Nitrogen runoff
  • 16. Eutrophication • Nutrients from artificial fertilizers find their way into fresh water systems and oceans as well as ground water • Excess nutrients in aquatic ecosystems lead to eutrophication • Eutrophication occurs when algae and plankton reproduce due to nutrient abundance. The decomposition of the dead organisms leads to the depletion of oxygen in the water
  • 17. Eutrophication • Algae blooms are a common indicator of eutrophication
  • 18. Eutrophication • Eutrophication for farm runoff has lead to the deterioration of many fisheries • For example, runoff from farms in the Mississippi River watershed has led to a “dead zone” in Gulf of Mexico that is about 5,600 square miles in size5
  • 19. Gulf of Mexico Dead Zone
  • 20. Pesticide Runoff • Excess pesticides also find their way into aquatic ecosystems • A USDA study found that 80% of urban streams and 50% of agricultural streams had concentrations of at least one pesticide above the USDA’s water quality benchmark for aquatic life6 • Contamination levels dangerous to human health is relatively rare, luckily6
  • 21. GENETICALLY MODIFIED CROPS http://docakilah.files.w genetically-modified.jpg
  • 22. GMOs • Genetically modified organisms (GMOs) are organisms that have been modified using genetic engineering • Advantages of GMOs are resistance to pests and shorter growing times • There is no scientific evidence that any currently produced genetically modified crops are any more dangerous to human health than normal crops8
  • 23. GENETICALLY MODIFIED CROPS Environmental Benefits anic-farmers-report-increasing-gmo- contamination-with-corn-2-2235/
  • 24. GMOs Environmental Benefits • Reduced pesticide spraying by 2.8 billion kg globally from 1996 to 20069 • This has resulted in a 15% reduction of environmental impact associated with pesticides and herbicides9 • Significantly reduced greenhouse gas emission on farms where used •Equivalent to taking 6.65 million cars off the road9
  • 25. GMOs Environmental Benefits, Continued • Growth of GMO cotton has been documented to cause an increase in biodiversity and beneficial insect life in both the US and Australia (due to lower herbicide and pesticide use).10
  • 26. GENETICALLY MODIFIED CROPS Environmental Risks whammy-for-the-monarch-butterfly/ /
  • 27. GMOs Environmental Risks • Outcrossing is the breeding of a domestic crop with a related species • GMO crops may create herbicide resistant weeds through outcrossing • This has not been a problem yet, but needs to be monitored on a case-by-case basis as new GMOs are introduced11
  • 28. GMOs Environmental Risks, Continued • In a laboratory environment, insect resistant corn pollen negatively affected monarch butterfly larvae • Butterfly populations in the wild located near GMO corn fields have not been shown to be affected though12 • Insect resistance to GMOs is always a concern, as it is with conventional pesticides
  • 29. Greenhouse Gas Emissions
  • 30. Greenhouse Gas Emissions The current US food system requires massive amounts of fossil fuel input to be maintained compared to how much food energy is actually produced
  • 31. Greenhouse Gas Emissions • Shipping from large monoculture farms contributes a large amount of CO2 in the atmosphere • On average, the typical American meal contains food from 5 different countries13 • It is estimated that the average America meal travels 1500 miles to get from farm to plate14 • For every 1kcal of food consumed, 10kcal of fossil fuel energy is used14
  • 32. Greenhouse Gas Emissions doc/CSS01-06.pdf
  • 33. Greenhouse Gas Emissions • N2O is another greenhouse gas. It is created by microbial processes in heavily fertilized fields • Corn, the most heavily subsidized crop, is also one of the most nitrogen dependent crops15 • N2O emissions from fertilizer accounts for 1.5% of all greenhouse gas emissions on the planet15
  • 34. What Can We Do? e/new-vendor-lonely- mountain-farm
  • 35. What Can We Do? • Eat local. Reduce the amount of fuel required to get food to you • Buy organic. • Not because its better for you, but because organic farming practices require less herbicide and pesticides (in theory) and therefore are better for the environment. • Fossil fuel use is also 30% less on organic farms than on conventional farms16
  • 36. What Can We Do? • Buy organic, continued • Crop rotation instead of using massive amounts of fertilizer reduces water pollution and prevents soil erosion15 • The more demand there is for organic produce, the more the big producers will begin to adopt organic farming practices on a large scale.
  • 37. References 1. Environmental Working Group. (2014). EWG Farm Subsidies: United States Summary Information. 2. Heller, M. and Keoleian, G. (2000). Life cycle-based sustainability indicators for assessment of the US food system. University of Michigan Center or Sustainable Systems, CSS00-04. 3. Sam Wood and Annette Cowie (2004). A Review of Greenhouse Gas Emission Factors for Fertiliser Production. IEA Bioenergy IEA Bioenergy. 4. Lal, R., and Stewart, B. (1990). Soil Degradation. Springer-Verlag, New York. 5. Board on Agriculture and Natural Resources, National Research Council. 2003. Frontiers in Agricultural Research: Food, Health, Environment, and Communities. Washington (DC): National Academies Press 6. Gilliom, R., Barbash, J., Crawford, C., Hamiliton, P., Martin, J., Nakagaki, N., Nowell, L., Scott, J., Stackelberg, P., Thelin, G., and Wolock, D. (2007). Pesticides in the Nation’s Streams and Ground Water, 1992-2001. USGS Circular 1291. 7. USDA, National Resources Conservation Service. (2009). 2007 National Resource Survey. 8. American Association for the Advancement of Science (AAAS), Board of Directors (2012). "Legally Mandating GM Food Labels Could Mislead and Falsely Alarm Consumers. could-%E2%80%9Cmislead-and-falsely-alarm 9. Barfoot, P., & Brookes, G. (2007). Global impact of biotech crops: Socio-economic and environmental effects, 1996-2006. AgBioForum, 11(1), 21-38. 10. Carpenter, J, A Felsot, T Goode, M Hammig, D Onstad and S Sankula. (2002). Comparative environmental impacts of biotechnology-derived and traditional soybean, corn and cotton crops. Council for Agricultural Science and Technology, Ames, Iowa. 11. Government of Canada. (1994). Assessment criteria for determining environmental safety of plants with novel traits. Dir. 9408, Dec. 16, 1994. Plant Products Division, Plant Industry Directorate, Agriculture and Agri-food Canada. 12. Sear, M, RL Helmich, DE Stanley-Horn, KS Obenhauser, JM Pleasants, HR Matilla, BD Siegfried and GP Dively. 2001. Impact of Bt corn pollen on monarch butterfly. PNAS 98(21):11937-11942 13. National Resource Defense Council. (2007). Food Miles: How far your food travels has serious consequences to your health and the environment. 14. CUESA. (2014). How far does your food travel to get to your plate? your-plate 15. Iowa State University.(2008). Global warming – agriculture’s impact on greenho gas emissions. 16. Pimentel, D., Hepperly, P., Hanson, J., Douds, D., and Seidel, R. (2005). Environmental, energetic, and economic comparisons of organic and conventional farming systems. BioScience(55)7: 573-582.