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1 “This…is the world that has been pulled over your eyes to blind you from the truth.“ - Morpheus, the Matrix (1999)

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Presentation on theme: "1 “This…is the world that has been pulled over your eyes to blind you from the truth.“ - Morpheus, the Matrix (1999)"— Presentation transcript:

1 1 “This…is the world that has been pulled over your eyes to blind you from the truth.“ - Morpheus, the Matrix (1999)

2 Written by James Dauray Textbooks used as reference: Living in the Environment by Miller Environmental Science by Cunningham & Cunningham More teaching resources and lectures available here: Last updated December 21, 2010 2

3 Producing enough food has become a greater challenge as the human population reaches 7 billion. Food energy is measured in calories. Undernutrition occurs when someone does not eat enough calories. Adults need on average 1000 calories per day to simply survive. Average of 2100 calories needed for a normal, healthy life. 3

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5 Chronic Hunger and Food Security About 925 million people are considered chronically undernourished or malnourished. Most of these are in developing countries. This is about 13% of the world’s population. Theoretically, there should be enough food to supply about 3000 kcal/day to everyone. 5

6 6 Source: Miller Environmental Science, 13 th Edition

7 Undernutrition – Insufficient caloric intake. Malnutrition - Nutritional imbalance caused by lack of specific dietary components. Overnutrition – A daily intake of calories that is too high, leading to obesity. The most common dietary problem in wealthy countries. Up to 64% of all adult Americans are overweight. 7


9 Iron deficiency is the most common dietary imbalance in the world. Leads to anemia – insufficient oxygen transported to the brain, muscles, and organs due to low red blood cell count. Symptoms include fatigue, dizziness, headache Increases risk of death in childbirth Good sources of iron: Red meat, eggs, beans, and some green vegetables (spinach, broccoli) 9

10 Iodine deficiency is another very common type of malnutrition, especially in rural developing areas. Iodine is required for production of thyroid hormones, which control the body’s rate of metabolism. Chronic lack of iodine can slow all parts of normal development, including body size and brain function. Lack of iodine can also cause a goiter, or a swollen thyroid gland. Good sources of iodine: seafood and plant crops from iodine rich soils. 10 Source: Miller Environmental Science, 13 th Edition

11 A famine is when large-scale undernourishment occurs in a population. Most of the population is eating less than the daily minimum calories needed (1000 calories) Drought causes more than half of famines. Other significant causes: war and bad governance. Ex: North Korea was reluctant to request foreign assistance after severe flooding in the 1990s. 11

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16 Aid from rich countries often can help alleviate famines in the short term. Drawbacks to foreign assistance: Population must crowd together in “food camps” to receive supplies. Lack of sanitation Quick spread of diseases Foreign aid tends to be short-lived as people’s attention moves elsewhere. Ex: Indonesian tsunami of 2004, Hurricane Katrina of 2005, Haiti earthquake of 2009, Pakistan floods of 2010 16

17 An estimated 90% of the world’s food calories come from 14 species of plants. Three of those crops deliver a majority of world’s nutrients: wheat, corn, and rice. Main nutrient component of these foods is carbohydrates. The major food staples are all plants. Cheaper and easier to produce. Why? Remember the energy pyramid? 17

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20 Meat and dairy products are all high in protein, iron, and come from animals. As incomes rise in developing countries, food choices shift towards higher-quality and more expensive foods. 60% of production occurs in lesser developed countries. Meat requires a high amount of grain to produce. 15 pounds of grain to produce 1 pound of meat. 20

21 Seafood is the biggest protein source in many island and coastal countries. Annual catches of ocean fish rose by 4% annually between 1950-1988. Many areas of ocean are now so overharvested that large-scale fishing is unsustainable. Nearly half of seafood harvested is now farmed. 21

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25 Much of the food produced in the developed world is the result of industrialized agriculture. Dependent on the use of heavy equipment, fuel, fertilizers, pesticides, and irrigation. Most food is grown as a monoculture, or single-crop farming. 25

26 Total food production has increased steadily in the last 50 years, in spite of a decrease in the actual number of farms. 26

27 The green revolution marked three major changes in farming and food production: 1. Usage of monocultures of highly-bred or genetically modified species. 2. Increased input of irrigation, fertilizer, herbicides, and pesticides. 3. Produce more than one type of crop each year on a plot of land. The net effect of the Green revolution and the industrial food system has been to keep food prices artificially low. Americans only spend 10% of their household income on food. 27

28 Agriculture accounts for largest single share of global water use. Most irrigation systems are inefficient. Only about 20% of water withdrawn for irrigation reaches the plant roots. Where does the rest go? Two main types of irrigation systems: Overhead sprinkler systems Underground drip systems 28

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31 Lack of three nutrients can slow plant growth: nitrogen, phosphorous, and potassium. Adding these nutrients via fertilizer usually stimulates growth and increases crop yields. 1950 - Average of 7kg/acre used 2000 - Average of 25kg/acre used Adding fertilizer and manure is replenishes soil nutrients depleted from previous years. Problems with fertilizer? Can runoff into water sources and cause aquatic plants (algae) populations to expand rapidly Manure can cause bacterial contamination 31

32 Industrialized farming is energy-intensive. Energy use in agriculture has risen for two reasons: Increase in use of machines Spraying of chemical pesticide and fertilizers In the U.S., the food system consumes 16% of total energy use. Most foods require more energy to produce, process, and transport than we yield from them. 32

33 Biological pests are any organisms that reduce crop yields. Examples: Insects, birds, rodents Pesticides are chemicals that are used to kill or repel biological pests. Half of current crop yields might be lost in the absence of pesticides. Residue from synthetic pesticides often remains on the skin of some fruit. Organic foods, by definition, do not use synthetic pesticides and herbicides. 33

34 The single biggest individual benefit of buying organic is the avoidance of pesticide residues. Not all produce has the same amount of residue. The “Dirty Dozen” – most contaminated produce Celery (64 different pesticides have been detected) Peaches Strawberries Applies Blueberries Nectarines Bell peppers Spinach Kale Cherries Potatoes Grapes (up to 34 different pesticides detected) Source: (list updated yearly) 34

35 The “Clean Fifteen” – least contaminated produce Onions Avacados Sweet Corn Pineapple Mango Asparagus Sweet peas Kiwi Cabbage Eggplant Papaya Watermelon Broccoli Tomato (look for greenhouse grown) Sweet potatoes Source: (list updated yearly) 35

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37 The industrialization of agriculture applies to the raising of livestock, both for meat and dairy. The traditional method of raising animals in open pasture is now largely a relic of the past, replaced by highly- mechanized large-scale operations. 37

38 Dairy cows are special breeds chosen for high milk production. About half of the U.S. dairy cows are raised in confined indoor pens. As with other mammals, cows only produce milk for about 10 months after giving birth. Must be continuously impregnated to continue milk production. Female calves are kept within the herd Male calves are usually sent to veal crates. 38

39 The advantage of raising dairy cattle indoors is that all aspects of their growth, feeding, and behavior can be monitored and controlled. Cows leave their pens twice a day to be milked mechanically. 39

40 The disadvantage is the rapid spread of disease due to the crowding and high amounts of waste manure. To prevent this, antibiotics are commonly administered to the cattle. Nearly half of all antibiotics used in the U.S. are used in farm animals. Farms may also inject their cattle with Bovine Growth Hormone (BGH) to increase milk production. 40

41 There are significant consequences to the use of additive hormones and antibiotics in cattle feed. Overuse of antibiotics is increases the risk of bacteria evolving resistance to the antibiotic. When this occurs, the antibiotic becomes unusable. The use of BGH has multiple effects: The overall health of the cows is affected: Increased likeliness of mastitis (infection of the udders) Increased rate of lameness Reduced fertility There are also effects on the milk itself: Increased growth hormone in the milk Increased pus in the milk, causing it to go sour more quickly 41

42 Penicillin is ineffective 25% of the time for strep throat; amoxicillin is ineffective 18% of the time. Source: University of Rochester StudyUniversity of Rochester Study 42

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44 Calves are kept in small crates that minimize the amount of movement they are able to make. Their diet is intentionally iron-deficient. This keeps their flesh pale 44

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46 The majority of hens (~95%) that supply eggs are raised in battery cages. These are small cages with slanted floors to drain waste. Hens are confined within small cages their entire life. USDA recommendations for cage size: Cages are usually 16 inches wide and contain 4 hens. The highly restricted movement of the hens leads to unusually aggressive behaviors. Beaks are cut or seared off to prevent fighting. 46

47 Chicks that are hatched are sorted by gender; females are kept; the males are killed and discarded. The layer hens are subject to near constant light to encourage greater egg production. Fatigue and mineral depletion are common. Egg production begins to decline when the hens reach about 12 months. At this point they are slaughtered and used in processed foods (soup, flavoring, pet foods, etc) The use of antibiotics and growth hormones is illegal in all poultry. 47

48 Broiler hens are chickens bred and raised specifically for meat. They have much larger thighs and breasts than normal; making them very heavy and often unable to stand or walk normally. Broiler chickens are raised in pens instead of cages to prevent bruising. Beaks and toes are removed to prevent fighting. The chickens reach their slaughter weight in about 2 months. 48

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51 Pigs are very sensitive animals, prone to sunburn and heat stress. As a result, they are primarily raised indoors in temperature-controlled “hatch pens”. Tails are usually cut off at birth to prevent biting – a common issue in overcrowded pens. 51

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54 Cattle / Pigs The animals are knocked unconscious either by electric shock or with a bolt gun. They are hung upside down by their hind legs. The carotid artery and jugular veins are cut, killing the animal by bloodloss. Poultry The animals are hung by their feet on a conveyor belt. They are passed through electrified salt water to stun them unconscious, then their throats are cut. The carcasses are then moved into a vat of boiling water, which makes feather removal easier. Kosher/Halal Animals are not stunned before slaughter. 54

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57 57 The “Smoking Fry” experiment

58 Beef The leftover fat, connective tissue, and organ pieces from slaughter is liquefied, mixed with ammonia (to reduce bacteria), and combined with ground beef. Carbon monoxide may also be added to meat packaging to preserve the red color as long as possible. 58

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60 The factory farming process makes food much cheaper than conventional methods. One big downside is an increase in the number of food recalls. 2010 Recalls 228 million eggs ( Salmonella ) 2009 Recalls Nestle Toll House cookie dough ( E.coli ) Pistachios ( Salmonella ) Products containing peanut butter / paste ( Salmonella ) 2008 Recalls Beef recall ( cattle were not inspected properly ) Maple Leaf brand deli meats ( listeriosis ) 60

61 61 Produced by Free Range Studios 2003,2006

62 Cage Free Chickens are not kept within cages, but may still be high- density indoor pens. Certified Humane Chickens are uncaged and “must be able to perform natural behaviors such as nesting”. Free Range Animals are kept outdoors and allowed to roam. 62 Organic No unnatural feeds or feed additives given to animals. No additives in the final product. Does not address treatment of animals

63 Arable Land – Land that is fertile and can be used to grow crops. Soil - A complex mixture of minerals, decomposing organic materials, and living organisms. Soil is generated from rock by two processes: Physical weathering – Rock is broken down by wind and water Chemical weathering – Rock reacts with substances such as acid or water. The best soils for farming have deep topsoil layers. Grasslands, deciduous forests. 63

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65 Much of the arable land on Earth has been lost. Estimates: 3 million hectares of cropland ruined annually via erosion, 4 million transformed into deserts 8 million paved or built upon. 65

66 Stepped Art Stable or nonvegetative Serious concern Some concern Fig. 10-9, p. 216

67 Desertification – Dry areas become more desert-like due to human activities. Overgrazing Global climate change 67

68 Erosion is any natural process that redistributes soil and minerals across the earth. Erosion becomes a problem when it occurs too quickly. Two biggest causes of erosion: Wind Water 68

69 Sheet Erosion - Thin, uniform layer of soil removed by high winds. Rill Erosion - Small rivulets of running water gather and cut small channels in the soil. Gully Erosion - Rills enlarge to form channels too large to be removed by normal tillage. Streambank Erosion - Washing away of soil from established streambanks. 69

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74 Wind can be a strong force of erosion, especially in a dry climate and on flat land. Wind erosion is worsened by intensive farming practices: Planting crops in rows, leaving the soil in between exposed. Having fields completely free of weeds Removal of windbreaks such as trees No crop-rotation or resting periods Continued monocultures Growing the same crop every year 74


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77 Managing Topography Contour Plowing - Plowing across slope to slow flow of water. Strip Farming - Planting different crops in alternating strips along land contours. Terracing - Shaping land to create level shelves of earth to hold water and soil. 77

78 Fig. 10-19, p. 229




82 Providing Ground Cover The most erosion occurs in fields that are bare – do not have any cover. Ways to avoid bare ground: Leave crop residue after harvest. Plant different crops each season. Lay down mulch. 82


84 Genetically Modified Organisms (GMO’s) Contain DNA possessing genes borrowed from unrelated species. Can produce crops with new traits only found in other species. Opponents fear GMOs are untested and may cause health effects when eaten, such as allergies 60% of all processed foods in North America contain transgenic products. Corn and soy 84

85 85 FoodPropertiesPercent Modified in US Soybeans Resistant to certain herbicides 89% Corn Resistant to certain herbicides Insect resistance - using Bt proteins from a bacterium Vitamin-enriched corn, with 169x increase in Vitamin A, 6x the vitamin C and 2x folate. 60% Cotton (cottonseed oil)Pest-resistant cotton83% Hawaiian papaya Variety is resistant to the papaya ringspot virus. 50%

86 86 FoodPropertiesPercent Modified in US Tomatoes Ripening enzyme is suppressed, lengthening shelf- life. Taken off the market due to commercial failure. Potatoes Produces amylopectin instead of starch.amylopectin Industrial production of amylopectin for glossy paper coatings and adhesive cement. CanolaResistance to herbicides,75% Sugar cane Resistance to certain pesticides, high sucrose content. ? Sugar beetResistance to herbicides? Sweet corn Produces its own bioinsecticide (Bt toxin) ? Rice Genetically modified to contain high amounts of Vitamin A ?

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