CH-7-8 Food Production and the Environment – Sustaining the Earth : Chapter Notes

This Document Contains Chapters 7 to 8 Chapter 7 Food Production and the Environment Summary and Objectives 7-1 What is food security and why is it difficult to attain? Wide-spread poverty makes it impossible for people worldwide to obtain (raise/buy) enough food to meet their nutritional/energy needs. CONCEPT 7-1 The greatest obstacles to providing enough food everyone are poverty, corruption, war, bad weather, and the harmful environmental effects of industrialized food production. 1. Explain why poverty is regarded as the root cause of hunger. 2. Define food security and food insecurity. How do they differ from nation to nation? 3. Distinguish among malnutrition, undernutrition, and overnutrition. Indicate how many people on the earth suffer from these problems and where these problems are most likely to occur. 4. Describe the harmful effects of diet deficiencies in vitamin A, iron, and iodine. 7-2 How is food produced? Food on earth is produced by pastures, rangelands, and ocean fisheries. The amount of agricultural products has been consistently increasing, but efforts to increase food production and nutrition, and environmental efforts are now lagging. Crossbreeding, genetic engineering, and polycultures of perennial crops have been advocated for increased crop yields. CONCEPT 7-2 We have used high-input industrialized agriculture and lower-input traditional methods to greatly increase food supplies. 5. Compare traditional and industrialized agriculture. Distinguish among industrialized (high-input) agriculture, plantation agriculture, traditional subsistence agriculture, traditional intensive agriculture, polyculture, and slash-and-burn agriculture. 6. Define soil and the major layers in mature soils. How does soil contribute to each of the four components of biodiversity? 7. Describe and evaluate the green revolution. 8. Distinguish between artificial selection and genetic engineering (gene splicing). 9. What are genetically modified organisms (GMOs or transgenic organisms)? Explain the advantages and disadvantages of genetically engineered foods. 10. Compare industrial fishing and aquaculture. 11. Describe the trends in total world fish catch since 1950 and explain what can be ascertained from the data. 7-3 What environmental problems arise from food production? Modern food production is perhaps the most harmful environmental impact caused by humans. CONCEPT 7-3 Future food production may be limited by soil erosion and degradation, desertification, water and air pollution, climate change, and loss of biodiversity. 12. Describe the problems of salinization and waterlogging of soils and how they can be controlled. 13. Describe the problem of soil erosion. Describe both world and U.S. soil erosion situations. Give an explanation for the ignorance about this problem. 14. Describe the advantages and disadvantages of using genetically modified crops and foods. Which two advantages and which two disadvantages do you think are the most important? Why? 7-4 How can we protect crops from pests more sustainably? Although there are problems with pesticides, they are used to improve crop production and yield. A more effective method to control pests would be copying nature’s methods of pest control and a limited use of pesticides—integrated pest management. CONCEPT 7-4 We can sharply cut pesticide use without decreasing crop yields by using a mix of cultivation techniques, biological pest controls, and small amounts of selected chemical pesticides as a last resort (integrated pest management). 15. List the five major classes of pesticides and what they are used to treat. 16. Give five benefits for using pesticides. 17. Describe five consequences of relying too heavily on pesticide use. 18. List five ways you could reduce your exposure to pesticides. 19. List and briefly describe seven alternative pest management strategies. Describe and evaluate integrated pest management. 7-5 How can we improve food security and produce food more sustainably? The three major ways to develop sustainable agriculture are to slow population growth, to reduce poverty, and to implement sustainable agriculture. CONCEPT 7-5A We can improve food security by creating programs to reduce poverty and chronic malnutrition, relying more on locally grown food, and cutting food waste. CONCEPT 7-5B More sustainable food production will require using resources more efficiently, sharply decreasing the harmful effects of industrialized food production, and eliminating government subsidies that promote such harmful impacts. 20 Compare conventional-tillage and conservation-tillage farming. List and briefly describe six strategies to prevent soil erosion. 21. List six ways to maintain soil fertility. Describe at least one advantage of using organic instead of inorganic fertilizer. 22. List the advantages and disadvantages of aquaculture and describe six ways that the process can become more sustainable. 23. Explain why a shift to consuming more grain-efficient forms of animal protein is a more sustainable form of meat production. 24. Describe sustainable agriculture. List at least three steps that could be taken to move the United States toward more sustainable agriculture. Key Terms food security food insecurity chronic Under nutrition hunger chronic malnutrition overnutrition industrialized agriculture high-input agriculture plantation agriculture traditional subsistence agriculture traditional intensive agriculture polyculture green revolution artificial selection genetic engineering genetically modified organisms (GMOs) fishery aquaculture soil erosion desertification soil salinization waterlogging pest pesticides integrated pest management (IPM) soil conservation organic fertilizer synthetic inorganic fertilizer animal manure green manure compost organic agriculture Outline 7-1 Food Security and Nutrition A. Food security is when every person in an area has daily access to enough nutritious food to have an active and healthy life. Today we produce more than enough food to meet the basic nutritional needs of every person on earth. B. Widespread poverty causes food insecurity and makes it impossible for some people to grow or buy enough food. 1. Both macronutrients such as protein, carbohydrates, and fats and micronutrients such as vitamins and minerals are necessary for good health and to resist disease. 2. With too little food, people suffer from chronic undernutrition (hunger). a. In children, this leads to mental retardation and stunted growth. b. Weakened children are more susceptible to infectious diseases. 3. Deficiencies of protein and other nutrients lead to malnutrition. 4. Each day 16,400 people die of undernutrition or malnutrition, a direct result of poverty. In less-developed countries, one out of every six people is chronically undernourished or malnourished. C. Vitamin deficiencies are common and worldwide, especially for vitamin A, iron, and iodine. 1. Many people worldwide suffers from a deficiency in vitamins or minerals. 2. One of five people worldwide suffers from anemia, which is an iron deficiency. D. Overnutrition occurs when food eaten exceeds the energy used, resulting in excess body fat. 1. Overweight and underweight people have similar health problems: lower life expectancy, susceptibility to disease/illness, lower productivity and quality of life. 2. In the U.S., about two out of every three American adults are overweight. 7-2 How Is Food Produced? Food on the planet is produced by croplands (77%), rangelands (16%), and ocean fisheries (7%). A. Our systems of food production depend on a small number of plant and animal species, making us vulnerable to disease, environmental degradation and climate change which could impact those species. B. All three systems have increased their food yields since 1960. 1. Technological advances have increased food production, or harvesting. 2. More sophisticated farming techniques have been developed. a. Expanded use of inorganic chemical fertilizers, irrigation, pesticides, and high-yield crops has developed. b. Intense farming methods, such as densely populated feedlots and enclosed breeding/growing pens, and aquaculture ponds or ocean cages have been implemented. C. Industrialized/high-input agriculture produces large quantities of a single crop (monoculture) or livestock animals 1. This uses much energy, water, fertilizers, and pesticides. 2. It is practiced on 25% of cropland, mostly in developed countries. 3. Plantation agriculture is industrialized agriculture, primarily in tropical developing countries. D. Traditional agriculture/low input provides about 20% of the food supply and is practiced by 39% of the world’s people. 1. Traditional subsistence agriculture typically supports a single farm family’s survival. 2. Traditional intensive agriculture strives to feed not only the farmer’s family but to produce additional food to sell as income. By using fertilizer, irrigating, etc., a higher yield is sought. a. Many practice polyculture, which involves planting a diversity of crops together that mature at various times. 1) Polyculture requires less fertilizer and water because of the root systems at different levels. 2) The soil is protected from wind and water erosion because crops are growing year-round. 3) Multiple habitats support natural predators of crop-eating insects so that fewer insecticides are needed. 4) There are less weeds and less need for herbicides. 5) With several crops, bad weather will not destroy every one of them. 6) Low-input polyculture produces higher crop yields than high-input monoculture. b. Slash-and-burn agriculture is a form of polyculture that involves burning and clearing small plots of tropical forest to grow as many as 20 different crops for a few years until soil is depleted. Polyculture plants many different crops. 3. The green revolution has increased yields in food production per unit of existing cropland. The following steps describe this revolution: a. Key grain crops of plant monocultures are bred or enhanced to produce high-yield varieties. b. High-yields are sustained by using large amounts of fertilizer, water, and pesticides. c. The number of crops grown per year is increased through multiple cropping. 4. There have been two green revolutions. a. The first revolution occurred in developing countries between 1950 and 1970. b. The second revolution has occurred since 1967 in developing countries with enough rain and/or irrigation capability. 1) Fast-growing dwarf varieties of rice and wheat, especially for tropical and subtropical climates, have been introduced. 2) Use of pesticides, water, and fertilizers, has enabled food yields to increase. 3) Several crops can be planted during one year, increasing food yields further. c. Such revolutions use machinery and fossil fuel to plant and harvest; green revolution agriculture uses 8% of the world’s oil output. 5. The U.S. agricultural system produces 17% of the world’s grain but affects the environment more than any other industry. (See Case Study: Industrialized Food Production in the United States) a. Agriculture has doubled crop yield, using no more land, since 1950. b. Large agri-businesses (huge corporate/family-owned farms) control three-quarters of U.S. food production. Labor and resource costs have decreased since 1950. E. Crossbreeding is known as the first gene revolution, and genetic engineering is the second gene revolution. 1. Crossbreeding through artificial selection, mixes the genes of similar types of organisms to develop genetically improved varieties of crops and livestock animals. It is a slow process and often takes 15-plus years. The varieties are useful only for 5–10 years; then, pests and diseases reduce the effectiveness of the new varieties. 2. Genetic engineering mixes genes of different organisms, creating improved strains of crops and livestock animals. a. This process takes half as much time as traditional methods to develop a new crop. b. It cuts costs and allows for all kinds of potential product development. c. Most of the world is entering the age of genetic engineering. F. Production and consumption of meat is steadily growing. 1. 50% of the world’s meat comes from unfenced grazing livestock, and the other 50% from feedlots. 2. Between 1950 and 2010 world meat production increased six-fold. 3. Meat production uses much water, more than one-third of the world’s grain, and produces large amounts of animal waste, and pollutes. G. Catching and raising more fish and shellfish 1. Fisheries focus on a particular aquatic species, in a given ocean area or inland body of water, to harvest for commercial markets. Many species are almost extinct from commercial “vacuuming” of the seas. 2. Aquaculture is the process of raising fish and shellfish in ponds and underwater cages for food, such as crops, rather than harvesting them in the seas and inland waters. a. Aquacultural production has increased over 40-fold since 1950. b. Aquaculture is the world’s fastest-growing type of food production. H. Industrialized food production relies on large amounts of energy; about 19% of all commercial energy in the U.S. Annually. Much of this energy comes from energy needed to grow, store, process, package, transport, refrigerate, and cook our food (plant or animal). 7-3 What Environmental Problems Arise from Food Production? According to many analysts, agriculture has greater harmful environmental impacts than any other human activity – possibility limiting future food production. A. Preserving the world’s topsoil is of great importance for feeding the world’s masses. 1. Land degradation occurs when the future ability of the land to support crops, livestock, or wild species is decreased. 2. Water, wind, and people cause soil erosion; soil components are moved from one place to another. a. Depletion of plant nutrients in topsoil through farming, logging, construction, overgrazing, and burning vegetation leads to loss of soil fertility. b. Eroded soil becomes sediment in surface waters where it pollutes water, kills fish, and clogs irrigation ditches, channels, reservoirs, and lakes. B. A UN and World Resources Institute report estimated that topsoil is eroding faster than it is replenished on 38% of the world’s cropland. 1. Desertification usually occurs on arid or semiarid land when the productive potential of the soil drops by 10% or more as a result of human activities and/or prolonged drought. 2. Loss of crop productivity can also result from repeated irrigation, which produces salt buildup and water logging of plant crops. a. Salts left behind when irrigation water is not absorbed into the soil can be left in the topsoil. This is called salinization. b. Waterlogging occurs when saline water (from irrigation) envelops the deep roots of plants. This saline water accumulates underground and raises the water table. C. Our food production systems have caused major losses of biodiversity, which is also related to agrobiodiversity—the world’s genetic variety of animals and plants used to make food. D. GM food (genetically modified food) has generated much controversy. 1. Supporters believe that GM foods may potentially solve the world’s food problems. 2. Advantages and disadvantages of GMF: See Figure 7-8. 3. Many unknowns remain – impact on ecosystems, spread among nonengineerd species, and others. E. The Green Revolution may not be expandable indefinitely. 1. The green revolution crop varieties require huge amounts of fertilizer and water. 2. The costs of these crops are too high for subsistence farmers in developing countries. 3. There is a limit to the yield that increasing fertilizers, water, and pesticides will produce. Finally, there will be no additional increase in crop yield. 4. As environmental effects take place, crop yields in some areas may well begin decreasing. 5. Seeds used throughout the world are fairly uniform, and this increases the vulnerability of the crop to pests, diseases, and harsh weather. F. Producing more meat has harmful environmental consequences. 1. Meat production uses large amounts of water, energy; produces large amounts of animal wastes. 2. Livestock production generates about 18% of the world’s greenhouse gases and 16% of methane. G. Aquaculture can harm aquatic ecosystems (Figure 7-10) 1. Needs large inputs of land, feed, and water. 2. Large waste output. 3. Can destroy mangrove forests and estuaries. 4. Uses grain to feed some species. 5. Fish raised on fish meal or fish oil can be contaminated with toxins such as PCBs. 7-4 How Can We Protect Crops from Pests More Sustainably? A. Natural enemies (predators, parasites, and disease organisms) found in nature control the populations of most pest species. 1. Pests compete with man for food, invade lawns/gardens, destroy wood in homes, spread disease, etc. 2. Man’s monoculture agricultural activities and pesticides upset natural population checks and balances. B. Chemicals kill or repel organisms we consider undesirable. 1. Pesticides or biocides include four types: insecticides that kill insects, herbicides that kill weeds, fungicides that kill fungi, and rodenticides that kill rats and mice. 2. Plants have developed chemicals such as these for millennia to ward off, deceive, or poison herbivores that eat them. 3. Pesticides are used widely in developed countries, but use in developing countries is quickly growing. a. Broad-spectrum agents are toxic to a wide range of species. b. Narrow-spectrum agents work against a well-defined, limited group of organisms. c. The persistence of pesticides varies; some remain deadly for long periods; some have a short life span. 4. Rachel Carson fought to provide information to the American public about the harms of pesticides. (See Individuals Matter: Rachel Carson) C. Pesticides provide several benefits. 1. Pesticides save lives and increase food supplies. a. Pesticides have saved millions of people from contracting malaria, bubonic plague, and typhus. b. Pests destroy 55% of the world's food supplies. 2. Pesticides increase profits for farmers. 3. Pesticides work quickly and affordably, have a long shelf life, and are easily shipped and applied. 4. When used properly, pesticides are safe; health risks are low compared to the benefits of the pesticides. 5. Newer pesticides are safer and more effective than the older ones. D. Pesticides do have problems of their own. 1. The pesticide can promote genetic resistance, destroy natural enemies of pest species, create new pest species, and remain active in the environment; and some harm wildlife and people. 2. Synthetic pesticides have not been too effective in reducing crop losses. (See Science Focus: Pesticides Do Not Always Reduce Crop Losses) a. Synthetic pesticide use has increased 33-fold since 1942, but more U.S. food is lost to pests today than was lost in the 1940s. b. Environmental, health, and social costs of pesticide use is five to ten dollars for every dollar spent on the pesticides themselves. c. Alternative pest control practices could cut the use of chemical pesticides in half for 40 major U.S. crops. Crop yields would not be reduced. 3. Pesticides do not stay where used; only 2% of insecticides sprayed on crops reach the pests. 4. Thousands of farm workers become ill and some die because they are poisoned by pesticides. 5. Children become sick and some die from pesticides stored in the home. Cancer also affects some people exposed to pesticide residues in food. 6. Some scientists suspect pesticides of causing genetic mutations, birth defects, and negative effects on the central nervous system of humans. E. Pesticide use is poorly enforced and inadequate in the United States. Some pesticides may be banned in the U.S. but still exported to other countries. 1. Some of these pesticides can return to the U.S. on imported food—creating a circle of poison. 2. Pesticides move in and out of countries, regulated or not. F. To control pests, copy nature and use her methods. 1. Use cultivation practices to fool pests. a. Rotate the types of crops so that pests will starve or get eaten by natural predators. b. Grow crops where major pests do not exist. c. Use plant diversity to reduce losses. d. Implant genetic resistance by using genetically engineered resistant crop strains. d. Let lawn grass grow at least three inches high to keep out weeds. e. Use natural predators, parasites, disease-causing bacteria, and viruses to help control pests. 2. Sex attractants/pheromones attract only one species, work in trace amounts, usually do not cause genetic resistance, and do not harm non-target species. They can usually be used to lure pests into traps or to attract natural predators. 3. Hormones can be used to disrupt an insect’s normal life cycle so the insect does not mature and reproduce. But they can takes weeks to kill the species, must be used at exactly the right time, and often don’t work with large numbers of insects. G. Integrated pest management—using ecological approaches, and as a last resort, small amounts of pesticides—is the best way to control crop pests. 1. IPM (integrated pest management) is used to reduce crop damage to an economically acceptable level. 2. IPM has worked remarkably well in Indonesia, Sweden, and Denmark. 3. IPM is important to pollution prevention because health risks from using pesticides would drop 75%. 4. Government subsidies and political interests, as well as opposition by pesticide manufacturers, undermine the shift to IPM. 7-5 How Can We Improve Food Security and Produce Food More Sustainably? A. Governments apply various agricultural policies to affect food production. 1. Price controls keep prices artificially low. 2. Farming subsidies and tax breaks encourage food production. 3. Allow market demand to determine prices. In this situation, poor people would suffer from likely rising food prices. B. We can increase food security by decreasing our food waste. C. Support local economies by buying as much locally produced food as possible. D. Soil conservation seeks ways to reduce soil erosion and restore soil fertility. 1. To reduce soil erosion, farmers must stop plowing and tilling, and keep the soil covered with vegetation. 2. Additional methods to reduce soil erosion include: a. Terracing converts the land into a series of broad, nearly level terraces that run across the contour of the land. This method holds water for crops and reduces runoff. b. Contour farming plows and plants crops in rows across the slope of the land, not up and down. c. Strip cropping plants alternating strips of a row crop with another crop that entirely covers the soil. d. Alley cropping/agroforestry plants several crops together in strips/alleys between trees or shrubs, which may provide fruit or fuelwood. 1) The shade of the trees/shrubs reduces evaporation and helps retain soil moisture. 2) Fruit, fuelwood, and trimming can be used as mulch. e. Windbreaks or shelterbelts of trees reduce wind erosion, help retain soil moisture, provide fuelwood, and support bird and insect habitats. E. Soil fertility can be maintained and restored by applications of fertilizers. 1. Organic fertilizer can be used to restore lost plant nutrients. a. Animal manure improves soil structure, adds nitrogen, and stimulates soil bacteria and fungi. b. Green manure plows freshly cut or growing green vegetation into the soil to increase organic matter and humus. c. Microorganisms in soil break down organic matter in leaves, food wastes, paper, and wood to form compost. 2. Crop rotation plants different crops to replenish the soil, especially if a previous crop has depleted the soil of certain nutrients. 3. Inorganic fertilizers, used with organic fertilizers, can restore soil fertility. a. Commercial inorganic fertilizers contain nitrogen, phosphorus, and potassium. b. These fertilizers can replace depleted inorganic nutrients, but not organic matter. F. Sustainably producing meat 1. Cattle raised on rangelands and pastures cause less environmental harm and require little or no grain. 2. Shift consumption to more grain-efficient forms such as poultry and herbivorous farmed fish. G. Practicing sustainable aquaculture 1. Restrict location of fish farms to reduce loss of mangrove forests and estuaries. 2. Improve management of aquaculture wastes. 3. Reduce escape of aquaculture species into the wild. 4. Use deeply submerged cages to protect some species from wave action and predators. 5. Certify sustainable aquaculture and label products accordingly. 6. Raise species that are lower on the food chain and feed on plants rather than other fish. H. Solutions for sustainable agriculture 1. There are three main ways to reduce hunger and malnutrition and reduce agriculture’s harmful effects on the environment. a. Slow population growth. b. Reduce poverty. c. Phase-in systems of sustainable agriculture/low-input agriculture/organic farming. 1) This type of farming yields lower carbon dioxide emissions and soil erosion. 2) It improves soil fertility and is generally more profitable than high-input farming. 3) It uses more than 50% less energy per yield unit than conventional farming. 2. Helping farmers make the transition to sustainable farming is essential. a. Undertake increased research. b. Provide demonstration projects throughout countries. c. Increase subsidies and foreign aid to promote sustainable agriculture. d. Train people and develop college curricula. 3. The goal is to feed the people of the world while sustaining and restoring the earth’s natural capital and living on the natural income the earth provides. Teaching Tips 1. Because a typical classroom is often filled with students of various learning preferences, a basic understanding of learning styles can prove to be helpful. Teaching to different learning styles is easier when each learning style can be recognized and accommodated. 2. There are many ways of classify different learning styles. One common classification is: active versus reflective, sensing versus intuitive, visual versus verbal, and sequential versus global. Realize that the strength of, or preference for, one learning style or another may vary, and may even fluctuate depending on the subject matter being learned. 3. Consider having students take a learning style profile questionnaire, especially if they seem to be struggling with the content of the class. A free and well-known learning style assessment can be found on the North Carolina State University’s website, http://www.engr.ncsu.edu/learningstyles/ilsweb.html. Here, students can quickly take the Index of Learning Styles Questionnaire, get instant results, and a detailed explanation for each learning style category. 4. Be aware of your preferred learning style as well, as this will likely determine your predominant teaching style. For example, if you are a verbal learner, then you will remember best with written and verbalized explanations of new material, and so it is very likely that you will prefer to present information using lecture and written material. Being alert to your dominant teaching style will assist you in intentionally varying your instructional approach. 5. Using a balanced multifaceted approach to teaching will ensure that the learning needs of all students are being sufficiently met. Furthermore, using multiple teaching modalities will benefit all students in learning and storing the new information. Term Paper and Discussion Topics Conceptual Topics 1. Soil. The web of life in the soil; soil formation and pioneer ecological succession; soils of your locale. 2. Human impact on the soil. Overgrazing and desertification; acid deposition as a threat to soil quality; sediment as a water pollutant; irrigation impacts. 3. Agricultural systems. Inorganic fertilizers; history of development of one crop or livestock species; green revolution; crops with designer genes; politics of American agriculture; feedlot beef cattle production in the Corn Belt; range livestock production in the American West; urban growth and the loss of prime cropland; modern food storage and transportation; comparisons of environmental impacts of traditional and industrial agricultural practices. 4. Hunger and food distribution. History of great famines; malnutrition and learning; the geography of malnutrition. 5. Fishing. Overfishing; aquaculture; the Peruvian anchovy story. 6. Pesticides. Pesticides as hazardous waste; pesticide hazards to agricultural workers; chlorinated hydrocarbons; organophosphates and carbamates; pyrethroids and rotenoids; biological amplification of persistent pesticides; DDT and malaria control; Agent Orange; the Bhopal accident; pesticide residues in foods; pesticide runoff as a threat to agriculture. 7. Pesticide alternatives. Integrated pest management; food irradiation; genetic control by sterilization: the screwworm fly; pheromones. Attitudes & Values 1. What soil type is most common in your area? What are the most common soil problems in your area? 2. What feelings do you have toward the soil? Do you feel humans have a right to use the soil in any way they choose? If not, what are the limits? 3. Do you feel nature can take care of any harm humans bring the soil? Do you feel new technologies will solve any problems humans create involving the soil? 4. Do you feel humans have a responsibility to protect the quality and fertility of the soil? If so, what steps do you think should be taken to protect the soil? 5. Have you ever fasted? If so, how did it feel? Do you feel everyone has a right to a healthy diet? Is using lifeboat ethics the best way to decide who gets to eat? 6. Do you favor greatly increased foreign aid to poor countries to help them reduce poverty, to improve environmental quality, and to develop sustainable use of their own resources? What is the best way to manage food distribution for foreign aid? 7. Do you favor a more equitable distribution of the world’s resources and wealth to greatly reduce the current wide gap between the rich and the poor, even if this means less for you? 8. Have you ever eaten food grown with fertilizers and pesticides? How did it taste? 9. Have you ever eaten organically grown food? How did it taste? Are you aware of places to obtain organically grown food in your area? 10. Do you prefer perfect looking fruits and vegetables grown with pesticides to slightly blemished fruits and vegetables grown without pesticides? 11. Do you favor regulation of pesticides exported from the United States? Should pesticides banned in the United States be exported to other countries? 12. Do you have an attachment to any particular piece of land? Explore the roots of your attachment. Is the land protected from erosion and other forms of land degradation? 13. Would you create a compost pile in your backyard? Provide three reasons as to why or why not. 14. Is the rapid deterioration of agricultural soils in the United States a sufficiently serious problem to warrant strict federal laws with heavy fines for farmers or ranchers failing to employ wise soil conservation methods? Arrange a class debate on this issue. 15. Rachel Carson’s Silent Spring. Which is better: a broad-spectrum or a narrow-spectrum pesticide? Action-Oriented Topics 1. Individuals. Soil testing methods and procedures; what individuals can do to prevent soil erosion and nutrient depletion on their own property; agricultural practices that restore nutrients and prevent erosion; composting; no-tillage farming; crop rotation; windbreaks; forestry practices that minimize erosion; ranching management that minimizes erosion. Sustainable agriculture: organic home gardening; neglected edible plants; composting; crop rotation; organic fertilizers; windbreaks. Safe disposal of household pesticides; homeowner strategies and tactics to reduce pesticide use. 2. Cities. Land-use planning and zoning. 3. National. Soil Conservation Service; policies, such as farm bills, that affect soil quality; Federal Insecticide, Fungicide, and Rodenticide Act. 4. Global. UN food conferences; 1982 UN Conference on the Law of the Sea; agricultural training and research centers in the developing countries. International sales of U.S.-produced pesticides whose use is banned in the United States; General Agreement on Tariffs and Trade (GATT) and its implications for U.S. regulations regarding pesticide levels in American foods. Activities and Projects 1. Invite a Soil Conservation Service representative to your class to discuss local soil conservation problems and erosion-control methods. 2. Take a class field trip to several farms or ranches in your locale that offer you the opportunity to contrast excellent soil management practices with poor ones. 3. As a class exercise, discuss the economic, political, social, and environmental consequences that might ensue if the fertile soils of the Great Plains and the Corn Belt were ruined by human-accelerated soil erosion. 4. With your class, visit several construction sites in your locale. Look for evidence of human-accelerated soil erosion and methods or practices employed to minimize it. 5. Have your students find poems, songs, or paintings that express intense human feelings about the land and soil of working farms or ranches. Discuss these feelings in the context of modern large-scale commercial agriculture or agribusiness. Explore human expressions of concern about hunger and starvation. 6. Ask an experienced practitioner of organic farming or gardening to visit the class and describe methods used to preserve the soil and maintain its fertility without using inorganic fertilizers and chemical poisons. If possible, arrange a field trip to investigate organic farming practices. 7. Ask students to find and bring to class photographs, songs, paintings, and literature reflecting human feelings for fishermen, whalers, and farmers. 8. Invite an agricultural economist to your class to discuss shifts in the United States from farming to agribusiness and the historical role of subsidies in agriculture. 9. Invite a representative from the United States Department of Agriculture (or some other informed source) to your class to discuss how U.S. political decisions, such as emergency foreign aid and global trade, affect U.S. farmers. 10. Invite a county agricultural agent to your class to discuss local agricultural problems and opportunities. What major changes in agricultural practices are likely to occur in the coming decades? With what consequences? What types of farming activities are carried on in your locale? What is the balance between large and small farms? What are the major products? How much of the produce is used in local areas? How much is shipped out and where does it go? What is the status of pesticide use and abuse in your locale? Try to determine what factors, including government programs, combine to keep farmers on the pesticide treadmill. 11. Have your students find works of art, literature, and music that show the relationship between humans and pests and share them with the class. 12. As a class exercise, have your students create a soil management plan (illustrated by sketches, drawings, or photographs) for a hypothetical badly eroded farm. 13. Take a field trip around the community with your class. See if you can identify any sloped areas that are eroding significantly. Try to discern if the land erosion is resulting in sediment pollution in surface waters. Investigate if anything is being done about it. Draw up a plan that would prevent further erosion. Share it with people who might be interested in implementing the plan. 14. As a class, locate the nearest land undergoing desertification. If possible, take a field trip and observe it firsthand. Research the change of rate of desertification in the last 10 years. Identify any measures that have been taken to slow the rate of desertification. Draw up a proposal that could slow the rate of desertification. 15. As a class, identify the nearest irrigation projects. If possible, take a field trip to observe irrigation in action. Identify any problems that have resulted from irrigation and what approaches are being taken to alleviate those problems. Identify any groups that are researching salinization and waterlogging in the area. If appropriate, create a plan that would reduce the irrigation problems. 16. As a class, plan a daily menu for a family of four receiving minimum welfare payments (consult local welfare agencies for current payment levels and use current food prices). Ask your students how they would like subsisting solely on this diet. 17. As a class exercise, determine what percentage of your diet—as individuals and as a group–consists of meat. What are some ecological implications of this amount of meat in the diet? What are the health implications? What are the alternatives? 18. Arrange a class debate on the proposition that food-exporting nations should use population control and resource development as criteria to determine which of the food-importing nations will receive top priority. Conduct a mock trial and follow it with mock appeals hearings for denied nations. 19. With the help of a chemist or other appropriate consultant, have your students evaluate the ingredients, uses, and warning labels of a representative sample of pesticides sold for home and garden applications. Are the instructions for use, storage, and disposal adequate? How much additional information should be supplied to further reduce the likelihood of harm to people and wildlife? 20. Are people generally aware of and concerned about the hazards of using pesticides on a large-scale, long-term basis? As a class project, conduct a survey of students or consumers to address these and related questions. What do the results imply for the role that education should play in dealing with pesticide-related problems? 21. Have your students interview the college landscaping staff about which pesticides, if any, they use on campus. What tradeoffs did they consider when deciding to use those pesticides? 22. Have your students contact wildlife and health officials to see if there have been any problems with pesticides affecting wildlife and human health in your area. BBC News Videos The Brooks/Cole Environmental Science Video Library with Workbook, Featuring BBC Motion Gallery Video Clips, 2011. DVD ISBN: 978-0-538-73355-7 (Prepared by David Perault) What is the environmental cost for your food? Suggested Answers for Critical Thinking Questions 1. Student answers will vary but should be based on counteracting the greatest obstacles to providing food to everyone (Concept 7-1). Some suggestions for actions to reduce chronic hunger and malnutrition locally are: i) Distribute food and vitamins to the poor. ii) Help educate people on the proper ways to maintain a balanced diet. iii) Rely more on locally grown food. iv) Make healthy food more easily available both in terms of cost and proximity to where people live. Actions to reduce chronic hunger and malnutrition in the world include: i) Improving food storage and distribution ii) Eating more grain-efficient forms of animal protein iii) Supporting local farmers in planting diverse crops 2. Student answers will vary but they may discuss the following: (a) An increase in genetically modified food would be favorable because it increases crop yield by engineering crops to be resistant to harmful factors and by increasing the rate of growth while using less resources such as water and fertilizer. Using genetically modified foods, more food can be produced and global food security can be increased. An increase in genetically modified food would be unfavorable because there is not enough information about the long-term potential harm these foods have on human health and ecosystems. There is also the potential for these foods to produce harmful toxins from plant cell mutations, introduce new allergens, prove harmful to beneficial insects, and can be generally lower in nutrition than non-genetically modified foods. (b) An increase in polyculture practices would be favorable, when used sustainably, as it not only implements the biodiversity principle of sustainability, it also reduces the chance of losing most or all of a year’s crop, as several crops are grown on the same plot simultaneously. An increase in polyculture practices would be unfavorable because when this approach is used extensively, slash-and-burn agriculture leads to more clearing of tropical forests than is sustainable, leading to depletion and degradation. 3. Answers to this question should consider the benefits of aquaculture (high yield, efficient, low fuel consumption, high profits) and the disadvantages (large inputs of land and water, large amount of waste produced, vulnerable to disease); and weigh those against the natural capital of coastal marshland. The student will decide if they oppose or support the issue based on where they place the most value. Safeguards or regulations for an aquaculture operation should involve requiring the farm location to cause minimal damage to forests, mangroves, and estuaries; including sustainable waste management and disease-control practices; preventing aquaculture species from entering the wild and certification labels for harvests produced using sustainable forms of aquaculture. 4. Student answers will vary but may include the following: (a) Widespread use of a pesticide can increase damage done by a particular pest by the pesticide destroying natural predators. Without the predator to maintain the pest’s population, the population can increase drastically and become a major problem. (b) Widespread use of a pesticide can create new pest organisms by accelerating the development of genetic resistance to pesticides by pest organisms. These pests, through natural selection, develop immunity to pesticides and come back stronger than before. 5. Albert Einstein’s quote is in reference to the harmful environmental consequences of some meat production. Industrialized meat production produces large amounts of pollutants and uses vast amounts of energy and water. Shifting to a vegetarian diet will put less pressure on grain-supplies as well as marine-fish. 6. Student answers will vary. 7. Student answers will vary Chapter 8 Water Resources and Water Pollution Summary and Objectives 8-1 Will we have enough usable water? The management of the world’s water supply is a huge 21st century challenge. Water is not equally available around the world; the location of the water, the type of water, and the demand for it all stress available water supplies. CONCEPT 8-1A We are using available freshwater unsustainably by wasting it, polluting it, and undervaluing this irreplaceable natural resource. CONCEPT 8-1B Freshwater supplies are not evenly distributed, and one of every six people does not have sufficient access to clean water. 1. Briefly describe the earth's water supply and its distribution. How does water flow through the hydrologic cycle? How does human activity interfere with the hydrologic cycle? 2. How much of the world's reliable runoff do we use? What impact will predicted population increases have on our water use? Describe two areas in the world with significant water scarcity. 8-2 How can we increase water supplies? Water supplies can be increased by building dams, transferring water from high water areas to low water areas, withdrawing groundwater, and desalination. CONCEPT 8-2 By pumping groundwater, building dams, transferring water, and using desalination, we can increase water supplies, but these strategies all create environmental problems. 3. Briefly describe three major water problems. Evaluate which of these problems is of most concern in the United States and in the region in which you live. 4. Evaluate increasing the water supply through use of dams and water transfer projects. Compare the advantages and disadvantages of increasing the water supply through use of groundwater, desalination, and water transfer. 8-3 How can we use water more sustainably? A blue revolution must take place in order to conserve water; two-thirds of the water that we have available is wasted through evaporation, leaks, overuse in irrigation, etc. CONCEPT 8-3 We can use water more sustainability by cutting water waste, raising water prices, slowing population growth, and protecting aquifers, forests, and other ecosystems that store and release water. 5. State how much water is wasted. Briefly describe measures that can be taken to reduce water losses through irrigation, industry, and home use. 6. What is one significant change you can make to conserve water? What would be the impact of increasing the cost of water on water use? 8-4 How can we reduce the threat of flooding? Natural flooding by streams produces rich floodplains and recharges groundwater supplies. Increased human activities in active floodplains have contributed to the significant damage and destruction that result from floods. Concept 8-4 We can lessen the threat of flooding by protecting more wetlands and natural vegetation in watersheds and by not building in areas subject to frequent flooding. 7. What are the factors that have led to flooding disasters in Bangladesh? 8. Describe ways to mitigate flood risks. What inherent risks are present in those approaches to flood control? 8-5 What are the causes and effects of water pollution? Both single sources and dispersed sources contribute to water pollution. Dispersed (nonpoint) sources are the most difficult to control. CONCEPT 8-5 Water pollution, caused mostly by agricultural activities, industrial facilities, and mining, and worsened by growth in population and resource use, causes illness and death in humans and other species, and disrupts ecosystems. 9. List eight common types of water pollutants and give an example of each. Distinguish between point and nonpoint sources of pollution. 10. How many people lack access to clean drinking water in the world? What is the impact of contaminated drinking water? 8-6 What are the major water pollution problems in streams and lakes? The ability of streams and lakes to naturally recover from pollution depends primarily on flow rate and the type of pollutant. CONCEPT 8-6 Addition of pollutants and excessive nutrients to streams and lakes can disrupt these ecosystems, and prevention of such pollution is more effective and less costly than cleaning it up. 11. Draw an oxygen sag curve to illustrate what happens to dissolved oxygen levels in streams below points where degradable oxygen-demanding wastes are added. 12. Compare problems of lake water pollution to those of stream pollution. List three ways to prevent cultural eutrophication and three ways to clean up cultural eutrophication. Summarize the state of the Great Lakes. 8-7 What are the major pollution problems affecting groundwater and other drinking water sources? The properties of groundwater (location, flow rate, temperature, etc.) make it extremely difficult to detect sources of pollutants or clean them up if it becomes contaminated. Bottled water has a significantly higher monetary and environmental cost without the assurances of cleaner water. CONCEPT 8-7 Chemicals used in agriculture, industry, transportation, and homes can spill and leak into groundwater and make it undrinkable; and polluted water can be purified, but protecting it through pollution prevention is the least expensive and most effective strategy. 13. List the major pollutants of groundwater and three ways to control groundwater pollution. 14. Summarize ways to purify drinking water. 8-8 What are the major water pollution problems affecting oceans? Much of the world's population lives on the coast, and with that comes significant pollution. As populations rise, ocean pollution may increase significantly with increased human activity. CONCEPT 8-8 The great majority of ocean pollution originates on land and includes oil and other toxic chemicals and solid waste, which threaten fish and wildlife, and disrupt marine ecosystems, and the key to protecting oceans is to reduce the flow of pollutants into coastal waters. 15. Compare freshwater pollution to ocean pollution. List three ways to protect coastal waters. 8-9 How can we best deal with water pollution? Many of the regulations that have reduced point-source pollution in developed countries (like the U.S.) were largely the result of bottom-up political pressure. The most important next step in controlling water pollution is to minimize it or prevent it altogether. Developing countries, in particular, need specific assistance to shift to pollution prevention. CONCEPT 8-9 Reducing water pollution requires that we prevent it, work with nature to treat sewage, cut resource use and waste, reduce poverty, and slow population growth. 16. Briefly describe two major laws that protect water quality in the United States. Outline the arguments for and against strengthening the Clean Water Act. 17. Briefly describe and distinguish among septic tanks, primary, secondary, and advanced sewage treatment. Describe biologist John Todd's approach to sewage treatment. Key Terms groundwater zone of saturation water table aquifers surface water surface runoff watershed drainage basin reliable surface runoff drought desalination floodplain water pollution point sources non point sources eutrophication cultural eutrophication septic tank primary sewage treatment secondary sewage treatment Outline 8-1 Will we have enough usable water? A. Freshwater is critical to our survival, yet one of our most poorly managed resources. 1. Only 0.024% of the planet's water supply is available to us as accessible freshwater. 2. Hydrologic cycle — natural recycling, purification, and distribution system. 3. Interference with natural cycles puts our water supply in jeopardy. 4. Differences in natural distribution of water and population creates water crises. B. Our freshwater comes from groundwater and surface water supplies. 1. Precipitation infiltrates the ground and resides in the spaces in soil and rock as groundwater. 2. Zone of Saturation: water completely fills spaces in rock. a. Water table is the top of this zone. 3. Deeper below surface: aquifers where groundwater flows a. Much like a saturated sponge where water seeps b. Bounded by water-tight rock layers 4. One-third of surface runoff is a reliable source of freshwater we can count on annually. 5. 70% of surface water/aquifer use is for irrigation; 20% for industry; 10% for cities/residences. See Case Study: Freshwater Resources in the United States. 6. Availability of surface water is influenced by climate, agricultural and industrial use, and population. 7. Water shortages will grow as droughts become more severe, populations grow, and human activity increases. Conflicts over water are quite likely as hydrological poverty increases. See Case Study: Water Conflicts in the Middle East: a Preview of the Future? 8-2 How can we increase water supplies? A. Water tables are falling due to unsustainable withdrawal of groundwater. As we withdraw too much groundwater and sea levels continue to rise, saltwater may be drawn into freshwater aquifers, making them undrinkable. B. Dams and reservoirs 1. Benefits: increase annual reliable runoff, reduce flooding, grow crops in arid areas, hydroelectricity 2. Challenges: millions of people displaced, flooding productive land, impaired ecologic al services of rivers, prolonged drought. C. Water transfer projects 1. Benefits: transfer water from water-rich areas to water-poor areas 2. Challenges: exemplified in Case Study: Aral Sea Disaster; elimination of wetlands, accumulation of salt, extinction of numerous native fish, climate alteration, expense of purifying drinking water D. Desalination 1. Benefits: opening up new supplies of drinkable water in very arid areas where salty water is more abundant 2. Challenges: high energy cost, many marine organisms killed, salty wastewater must be disposed of (often dumped into ocean, threatening that environment) 8-3 How can we use water more sustainably? A. Reduce water waste. 1. Much of the world's water is lost unnecessarily due to leaks, evaporation, or waste. 2. Main cause of waste: low cost to users due to subsidies; few subsidies for improving efficiency 3. Irrigation: change from flood irrigation method to center-pivot or drip irrigation methods 4. Industry/homes: reduce toilets that use drinking-quality water (change to composting toilets), use more water-friendly landscaping B. Sustainable use 1. Use less water, use resources sustainably, preserve forests/wetlands/watersheds, slow population growth. 2. Cut water waste, raise prices, and replace lawns with native plants that need minimal water. 8-4 How can we reduce the threat of flooding? A. Floodplains provide natural flood and erosion control and recharge groundwater supplies. 1. Fertile floodplains are attractive places for farms and residential areas. 2. Living in floodplains and removing natural vegetation contribute to significant damages when flooding occurs. 3. In Bangladesh, one of the world's poorest countries, many people live in what was once coastal mangrove forests. This significantly increases the risk of flooding and loss of life when cyclones or heavy monsoon rains hit the area. See Case Study: Living Dangerously on Floodplains in Bangladesh, B. Reducing flood risks 1. Channelization can reduce risk and yet increase human settlement in floodplains. 2. Levees, dams, and floodwalls can offer local protection, but can increase risks downstream. Nothing can guarantee protection from severe storms. 3. Protecting existing wetlands and restoring damaged wetlands offers natural flood control and protects biodiversity. 8-5 What are the causes and effects of water pollution? A. Point sources and nonpoint sources 1. Point sources: discharge pollutants at specific locations. Fairly easy to identify, monitor, regulate. 2. Nonpoint sources: broad areas where pollutants originate. Very difficult to identify, monitor, regulate. a. Agricultural activities, industrial activities, and mining are leading causes of water pollution. b. Urban runoff (parking lots, lawns, etc.) is also a significant source of water pollution. c. As climate change alters local precipitation levels, transportation of pollutants will also be altered. B. Harmful effects of water pollution (See Table 8.1) 1. Spread of infectious diseases a. 1.6 million people die prematurely each year from infectious diseases spread by contaminated water. b. Majority of those who become ill are children. 2. Organic and inorganic chemicals increase toxins in water. 3. Sediments from land erosion disrupt food webs and photosynthesis. 4. Thermal pollution (heated water) from power plants and industrial plants increases disease susceptibility for some organisms. 8-6 What are the major water pollution problems in streams and lakes? A. Streams can recover from moderate pollution through dilution and bio-degradation. 1. Stream flow rate, pollution amount, and pollution type determine how effectively the stream can break down the pollutant. 2. An oxygen sag curve is created as bacteria degrade oxygen-demanding wastes. a. As stream flow continues away from the point source, stream oxygen levels recover. b. Organisms with high oxygen demands are eliminated until the stream is cleaned of wastes. B. Water pollution in developed versus developing countries 1. Developed countries have successfully reduced water pollution with wastewater treatment plants and regulations. 2. In developing countries, stream pollution from untreated sewage and industrial waste is a significant problem. C. Lake pollution 1. Lakes are not able to dilute most pollutants due to little vertical mixing and low flow rate. 2. Contaminants can kill fish and other wildlife that feed on contaminated aquatic organisms. D. Cultural eutrophication 1. Human activities can increase the input of plant nutrients into a lake. 2. During hot weather, these nutrients support excess growths of algae and cyanobacteria and water plants. 3. The degradation of these plants and bacteria reduce the oxygen in the water, killing fish and other organisms. 4. Eutrophication can be prevented through water treatment, reducing use of phosphates in household cleaners, and controlling soil runoff. 5. Lakes can be cleaned up by removing excess plants, controlling algae growth, and pumping oxygen into the lake. These methods are very costly. 6. The Great Lakes are very vulnerable to pollution due to their low flow rate and high nearby population. (See Case Study: Pollution in the Great Lakes) a. Pollution control methods have significantly decreased algal blooms and increased dissolved O2. b. Significant challenges remain, especially from sewage, urban runoff, and atmospheric deposition. c. Invasive species are also threatening native species and causing billions of dollars in damage. 8-7 What are the major pollution problems affecting groundwater and other drinking water sources? A. Groundwater supplies drinking water for half the U.S. population and 95 percent in rural areas. Contamination of groundwater is particularly difficult to manage. 1. Contamination is not easily cleansed, as groundwater flow rate is incredibly slow. 2. Bacterial decomposition of wastes is limited; chemical reactions are slowed due to cold temperatures. B. Pollution of groundwater often goes undetected in both developed and developing countries. 1. Lack of detection due to lack of testing, difficulty of locating sources, delay in time between start of leak and detection. 2. Prevention is the only effective protection for groundwater. Cleanup strategies are highly expensive and invasive. C. Pure drinking water 1. In developed countries, reservoirs and purification plants provide clean drinking water. 2. In developing countries, simple measures such as using UV light from the sun can help purify drinking water when systems for purification are lacking. 3. Bottled water is costlier (both financial and environmental costs) than tap water in places with high-quality drinking water, such as the U.S. (See Case Study: Is Bottled Water a Good Option?) 8-8 What are the major water pollution problems affecting oceans? A. An estimated 80% of marine pollution begins on land; a number that is sure to increase as population centers near the coasts grow. 1. Raw sewage and agricultural runoff contribute significantly to ocean pollution. 2. These nitrates and phosphates cause algal blooms, creating a toxic environment for fish and other marine life. 3. The Chesapeake Bay is an example of a polluted estuary that has benefited from the community's efforts to reduce pollution sources. See Case Study: Chesapeake Bay – an Estuary in Trouble. B. Petroleum products are serious ocean pollutants. 1. Urban runoff is the largest source of ocean oil pollution. 2. Oil coats birds' feathers and mammals' fur, destroying their natural insulation and buoyancy. 3. Recovery from a spill of refined oil is particularly difficult, taking 10–20 years, compared to recovery from a crude oil spill, which takes about 3 years. 4. Preventing oil pollution is the most effective strategy—double hull oil tankers will make a significant impact in prevention, yet only 50% of tankers have double hulls. C. The key to preventing ocean pollution is to reduce pollutant flow that results from human activities on land. 8-9 How can we best deal with water pollution? A. Reduce surface water pollution from nonpoint sources 1. Agricultural sources include soil erosion from unplanted areas, fertilizers, lack of buffer zones between crops and surface water, pesticides, and runoff from animal waste. B. Reduce surface water pollution from point sources. 1. The Clean Water Act (1977) and the Water Quality Act (1987) are the basis of U.S. efforts to control point source pollution. See Case Study: US Experience with Reducing Point-Source Pollution. 2. Between 1992 and 2002, water pollution in the U.S. has been significantly reduced as a result of the Clean Water Act, yet significant challenges remain. a. Calls for strengthening the Clean Water Act include ideas to promote pollution prevention, increase fines for regulation violators, regulate irrigation water quality, and increase wetland restoration. b. Opposition to increased regulation comes from farmers and other property owners who view these proposals as too restrictive. They also desire compensation for property value losses due to wetland conservation efforts. C. In urban areas in the U.S., like most developed countries, wastewater is treated in sewage treatment plants. 1. Primary sewage treatment removes floating objects and allows solids to settle. 2. Secondary sewage treatment uses bacteria to remove biodegradable, oxygen-demanding wastes. 3. Before discharge into waterways, water from treatment plants is disinfected, usually via chlorination. 4. Composting toilets and other biological solutions can help reduce the need for wastewater treatment. 5. See Science Focus: Treating Sewage by Working with Nature. D. The principles of sustainability can guide our approach to reducing water pollution. 1. Use solar energy to desalinate water to increase supply and purify the water we use. 2. Recycle more water. 3. Preserve biodiversity by avoiding disruption of aquatic ecosystems. 4. Controlling population growth will help use resources more sustainably and maintain quality. Teaching Tips 1. To engage students at the beginning of the chapter, use one or two of the Attitudes & Values discussion questions (see below) as small group discussions. Groups can then report their discussions to the class. Alternatively, have students complete a two-minute “quick write” to capture their ideas about the topic. Using these quick writes throughout the semester is a good way to help assign a participation grade. 2. Supplementing the textbook with local stories of water use, water pollution, water shortages, etc. keeps students connected with their community and helps them relate what they read in the textbook to real life. Students may be well aware of local or regional issues, but they may not (especially those who live in other places)—bringing them up in class and encouraging understanding of the complexities of these situations is beneficial from not only an environmental perspective, but from a socio-political one, as well. 3. Helping students understand life in developing countries is valuable, and they often find it very interesting. Seek out projects to describe to the class that involve water purification, sanitation, or other related topics. When students see that sometimes complex and seemingly insurmountable problems in the world often have straightforward solutions that real people came up with, the world gets a little bit smaller. Three sample projects are listed in the Internet Resources section below. You can find other projects related to water, sanitation, and other environmental issues at The Tech Museum Awards website (http://www.techawards.org), or the Design for the Other 90% exhibition website (http://www.cooperhewitt.org/tags/design-other-90). Search for projects related to “water” or “environment.” You will find several different water purification and water supply projects that may be of interest to your students. 4. Water quality and abundant supply is something we take for granted in most parts of the United States. Asking students to carefully monitor their water use and waste is a way to help raise awareness of just how much water we use on a daily basis. Term Paper and Discussion Topics Conceptual Topics 1. Flooding. History of flooding in the United States or Asia: change in rates and possible causes. Mississippi River flooding (1993, 2008), flooding associated with Hurricane Katrina in New Orleans (2005). 2. Droughts. Drought history of the African Sahel. Drought in the U.S.: Southeast, California. 3. Water supply through dams and water transfer projects. Trickle irrigation; water diversion projects in China (Three Gorges Dam) and India; new dams in South America and their effects on indigenous people. Aral Sea changes. Water supply for the southwest U.S. and the Colorado River. 4. Water supply through groundwater. Urban construction and aquifer recharge problems; the Kissimmee River story; groundwater use and land subsidence in central Florida; the Ogallala Aquifer. Water “banking” in underground aquifers. 5. Water pollution. Animal feedlot wastes; electric power plants and thermal pollution; waterborne disease-causing agents and their control; waterborne disease problems in developing countries; pesticides; deep-well disposal and groundwater contamination; sanitary landfills and groundwater contamination; hazardous storage and disposal problems; Exxon Valdez oil spill; leaking underground gasoline tanks; salinity problems in irrigated areas. 6. Case studies in water pollution. The fight to save Lake Erie; Lake Baikal; James River fuel spill; Chesapeake Bay; ocean dumping in the New York Bight. Attitudes & Values 1. Do you consume too much water? Does your community consume too much water? 2. Do you feel your community is doing enough to provide water? Do you feel other strategies should be tried? 3. Are you confident that your community has an adequate water supply for the needs of the community for the next decade? Do you feel other strategies should be tried? 4. What are your feelings toward increasing water supply through building dams? 5. What are your feelings toward increasing water supply through more withdrawal of groundwater? 6. Do you favor metering water use and charging water consumers the full cost of providing fresh water? 7. Do you favor increasing the price of irrigation water to reflect its true cost and encourage conservation among farmers? 8. Do you favor local ordinances that conserve water (such as the low-use toilet requirement for new housing)? 9. Would you support sharp increases in monthly water bills for all homes, buildings, and industries to discourage water waste? 10. How responsible are upstream communities for ensuring that high-quality water is delivered to downstream communities? 11. What are human attitudes toward cleanliness of water resources? 12. Is the public ready for water recycling? Action-Oriented Topics 1. Individuals acting to conserve water. New uses for residential “gray” water; water-saving showers, faucets, and toilets. Scientific methods of analyzing water. Groundwater pollution testing and monitoring; water quality testing, such as with Hach kits. Individuals acting to prevent water pollution. Grassroots movements to protect river watersheds and prevent ocean dumping. 2. State. The California Water Plan. Droughts in California and Arizona. Conflicts over water supplies. 3. National. The Safe Drinking Water Act of 1974; protection of groundwater; the Clean Water Act; problems in enforcing water quality standards; the role of the Environmental Protection Agency in water quality management; the Toxic Substances Control Act; the National Eutrophication Survey; the Coastal Barrier Resources Act; water-rights battles in the West. 4. Global. Conflicts over water supply: Jordan and Israel; Turkey and Iraq; Ethiopia and Egypt. UN Conference on the Law of the Sea. Activities and Projects 1. Ask your class to determine the local agricultural and industrial uses of water. Is irrigation used widely? What is the source of irrigation water? What water conservation practices are used by local government, industry, and agriculture? 2. Ask your students to bring to class and share paintings, photographs, poems, songs, or other expressions of intense human feelings about water as a life-sustaining and precious substance. 3. Invite a local, state, or federal water-supply official to discuss water-supply problems of your area with your class. Investigate the water-supply needs of your area and the strategies that are being used to meet those needs. 4. Ask your students to bring to class and share paintings, photographs, poems, songs, or other expressions of human feelings about water and/or water pollution. 5. Invite a local, state, or federal water pollution control official to discuss water pollution control methods, progress, and problems with your class. 6. Visit a sewage treatment plant with your class. Find out what level of sewage treatment is used in your community. What is the volume of effluent discharged? If effluent is discharged into a river or stream, is the water subsequently used for drinking water supply? Are there bodies of water in your locale unfit for fishing or swimming because of inadequately treated sewage effluent? If so, is anything being done to correct the problem? BBC News Videos The Brooks/Cole Environmental Science Video Library with Workbook, Featuring BBC Motion Gallery Video Clips, 2011. DVD ISBN: 978-0-538-73355-7 (Prepared by David Perault) Kalahari Desert Could Double in Size Half the World Denied Basic Sanitation Carbon Dioxide's Impact on Our Oceans Suggested Answers for Critical Thinking Questions 1. Answers will vary, but may include some of the following concepts. There are many ways to cut water waste in daily life: do not leave water running while washing dishes or brushing teeth; only run dishwasher when full; only do full loads of laundry and use least amount of water possible; avoid watering landscaping during heat of the day; wash car using bucket of water without running water; take shorter showers; etc. There are many ways to protect aquifers by preventing pollution from urban runoff, keeping watersheds clean (and protected, keeping toxic substances out of storm drains, and being active politically to pressure lawmakers to protect aquifers and aquatic ecosystems. 2. Answers will vary, but may include the following considerations. (A) (For) Raising the price of water will promote conservation and reduce wasteful use of this limited resource. However, we must have basic, affordable (lifeline) rates for poor and lower middle class families to ensure their basic water needs will be met. With higher prices, people will alter their habits and become much more aware of how little things, such as watering the lawn, can make a big difference. Hitting people in the pocketbook is often the only way to make them pay attention to a serious problem and change their habits accordingly. (Against) We cannot raise the price of water without hurting businesses and individuals significantly. We should not have different prices—everyone should pay the same price for water they use, regardless of income. We all use this precious resource; we should pay equally for what we use. Businesses would certainly be hurt by higher prices, especially those with high water demands, such as industry. My city/state can't survive another big company moving their manufacturing plant overseas and taking jobs away from our area. (B) (For) Irrigation inefficiency is a significant source of wasted water, thus improving agricultural water use will help the environment significantly. Without subsidies, farmers cannot make enough return on the investment to make their environmentally sound efforts financially worthwhile. If they were to pass the cost along to consumers, we would not be able to afford food. (Against) The government provides enough subsidies to farmers already; we cannot afford to continue to pay farmers. Our food costs need to increase to reflect the true costs of bringing these products to market, without government subsidies. 3. 2 drops / second x 60 seconds/minute x 60 minutes/hour x 24 hours/day x 30 days/month = 5,184,000 drops in one month. This is 1,481 liters or 392.5 gallons. 4. Answers will vary, but may include the following considerations. (A) To control pollution from a factory pipe, install treatment process before water leaves factory to reduce/remove toxins, cool water (thermal pollution), and ensure the stream flow is sufficient to dilute and process the waste that does enter the stream. (B) To control pollution from parking lot, ensure drainage does not directly flow into stream, regularly clean parking lot to remove oil/gas/other chemicals, clean out drains regularly to prevent litter from entering stream. (C) To control pollution from a farmer's field, design a buffer zone so that pesticide, fertilizer, and animal waste runoff does not directly flow into stream. Encourage use of organic farming methods, reduce pesticide use, etc. 5. Population growth contributes to groundwater pollution problems by increasing human activities that result in groundwater pollution—industrial, mining, increased use of pesticides and fertilizers in agricultural activities, increased use of oil, gasoline, and other household toxins that are dumped into the ground can also contaminate groundwater. Increased use of these items as well as these potentially toxic sources spread into new areas previously uninhabited or unused for human activities. New roads, new subdivisions, new gas stations, etc. Coastal pollution can also increase as population increases, as the majority of the marine pollution originates on land (80%). Runoffs from sewage plants and agricultural activities are the most toxic. Nonpoint sources as well, such as oil and gasoline from parking lots, fertilizer and pesticides from lawns, etc. is also a significant ocean polluter—all things that will easily increase as populations increase and new population centers are built in coastal areas. 6. Answers will vary, but should include the basics of water going down toilet, through pipes out of house, to city sewer lines and to wastewater treatment plant. Alternatively, some students will live on septic tanks, where water travels to septic tank underground near the house (usually downhill). Treated wastewater released into the environment can be researched with local water treatment plant. 7. These answers will vary, depending on your community's water source. Many water districts or local environmental organizations have much of this information available online or in annual reports. Instructor Manual for Sustaining the Earth G. Tyler Miller, Scott E. Spoolman 9781285769493