THE GENE REVOLUTION

1. THE GENE REVOLUTION • The winged bean, a GMF, could be grown to help reduce malnutrition and the use of large amounts of inorganic fertilizers. Figure 13-20

2. How Would You Vote? To conduct an instant in-class survey using a classroom response system, access “JoinIn Clicker Content” from the PowerLecture main menu for Living in the Environment. • Do the advantages of genetically engineered foods outweigh their disadvantages? • a. No. The impact of these foods could cause serious harm to the environment or human health. • b. Yes. These foods are needed to combat world hunger.

3. THE GENE REVOLUTION • Controversy has arisen over the use of genetically modified food (GMF). • Critics fear that we know too little about the long-term potential harm to human and ecosystem health. • There is controversy over legal ownership of genetically modified crop varieties and whether GMFs should be labeled.

4. How Would You Vote? To conduct an instant in-class survey using a classroom response system, access “JoinIn Clicker Content” from the PowerLecture main menu for Living in the Environment. • Should labeling of GMFs be required? • a. Yes, people have the right to make informed decisions about what they are buying. • b. No, research shows that GM organisms are safe. Labeling will scare consumers and penalize producers.

5. PRODUCING MORE MEAT • About half of the world’s meat is produced by livestock grazing on grass. • The other half is produced under factory-like conditions (feedlots). • Densely packed livestock are fed grain or fish meal. • Eating more chicken and farm-raised fish and less beef and pork reduces harmful environmental impacts of meat production.

6. Trade-Offs Animal Feedlots Advantages Disadvantages Increased meat production Need large inputs of grain, fish meal, water, and fossil fuels Higher profits Concentrate animal wastes that can pollute water Less land use Reduced overgrazing Reduced soil erosion Antibiotics can increase genetic resistance to microbes in humans Help protect biodiversity Fig. 13-21, p. 289

7. How Many People can the World Support? Food Production and Population • The number of people the world can support depends mostly on their per capita consumption of grain and meat and how many children couples have. • Research has shown that those living very low on the food chain or very high on the food chain do not live as long as those that live somewhere in between.

8. PRODUCING MORE MEAT • Efficiency of converting grain into animal protein. Figure 13-22

9. Kilograms of grain needed per kilogram of body weight Beef cattle 7 Pigs 4 Chicken 2.2 Fish (catfish or carp) 2 Fig. 13-22, p. 290

10. CATCHING AND RAISING MORE FISH AND SHELLFISH • After spectacular increases, the world’s total and per capita marine and freshwater fish and shellfish catches have leveled off. Figure 13-23

11. Per capita catch (kilograms per person) Catch (millions of metric tons) Wild catch Aquaculture Year Year Total World Fish Catch World Fish Catch per Person Fig. 13-23, p. 291

12. CATCHING AND RAISING MORE FISH AND SHELLFISH • Government subsidies given to the fishing industry are a major cause of overfishing. • Global fishing industry spends about $25 billion per year more than its catch is worth. • Without subsidies many fishing fleets would have to go out of business. • Subsidies allow excess fishing with some keeping their jobs longer with making less money.

13. How Would You Vote? To conduct an instant in-class survey using a classroom response system, access “JoinIn Clicker Content” from the PowerLecture main menu for Living in the Environment. • Should governments eliminate most fishing subsidies? • a. No. At least some subsidies are needed for the fishing industry to survive and provide needed food for people. • b. Yes. Government subsidies only encourage overfishing.

14. Aquaculture: Aquatic Feedlots • Raising large numbers of fish and shellfish in ponds and cages is world’s fastest growing type of food production. • Fish farming involves cultivating fish in a controlled environment and harvesting them in captivity. • Fish ranching involves holding anadromous species that live part of their lives in freshwater and part in saltwater. • Fish are held for the first few years, released, and then harvested when they return to spawn.

15. Trade-Offs Aquaculture Advantages Disadvantages High efficiency Needs large inputs of land, feed, and water High yield in small volume of water Large waste output Destroys mangrove forests and estuaries Can reduce overharvesting of conventional fisheries Uses grain to feed some species Low fuel use Dense populations vulnerable to disease High profits Tanks too contaminated to use after about 5 years Profits not tied to price of oil Fig. 13-24, p. 292

16. Solutions More Sustainable Aquaculture • Use less fishmeal feed to reduce depletion of other fish • Improve management of aquaculture wastes • Reduce escape of aquaculture species into the wild • Restrict location of fish farms to reduce loss of mangrove forests and estuaries • Farm some aquaculture species in deeply submerged cages to protect them from wave action and predators and allow dilution of wastes into the ocean • Certify sustainable forms of aquaculture Fig. 13-25, p. 293

17. How Would You Vote? To conduct an instant in-class survey using a classroom response system, access “JoinIn Clicker Content” from the PowerLecture main menu for Living in the Environment. • Do the advantages of aquaculture outweigh its disadvantages? • a. No. Although there are advantages, aquaculture causes significant environmental damage. • b. Yes. Aquaculture can protect wild marine species from commercial extinction.

18. SOLUTIONS: MOVING TOWARD GLOBAL FOOD SECURITY • People in urban areas could save money by growing more of their food. • Urban gardens provide about 15% of the world’s food supply. • Up to 90% of the world’s food is wasted. Figure 13-26

19. Government Policies and Food Production • Governments use three main approaches to influence food production: • Control prices to keep prices artificially low. • Provide subsidies to keep farmers in business. • Let the marketplace decide rather that implementing price controls.

20. How Would You Vote? To conduct an instant in-class survey using a classroom response system, access “JoinIn Clicker Content” from the PowerLecture main menu for Living in the Environment. • Should governments phase out subsidies for conventional industrialized agriculture and phase in subsidies for more sustainable agriculture? • a. No. Current subsidies maintain critical food supplies that should not be disrupted to Americans and others. • b. Yes. Agricultural pollution is a serious problem and subsidies should be used to encourage environmentally friendly agriculture.

21. Solutions: Steps Toward More Sustainable Food Production • We can increase food security by slowing populations growth, sharply reducing poverty, and slowing environmental degradation of the world’s soils and croplands.

22. PROTECTING FOOD RESOURCES: PEST MANAGEMENT • Organisms found in nature (such as spiders) control populations of most pest species as part of the earth’s free ecological services. Figure 13-27

23. PROTECTING FOOD RESOURCES: PEST MANAGEMENT • We use chemicals to repel or kill pest organisms as plants have done for millions of years. • Chemists have developed hundreds of chemicals (pesticides) that can kill or repel pests. • Pesticides vary in their persistence. • Each year > 250,000 people in the U.S. become ill from household pesticides.

24. Animation: Pesticide Examples PLAY ANIMATION

25. PROTECTING FOOD RESOURCES: PEST MANAGEMENT • Advantages and disadvantages of conventional chemical pesticides. Figure 13-28

26. Advantages Disadvantages Save lives Promote genetic resistance Increase food supplies Kill natural pest enemies Profitable to use Create new pest species Work fast Pollute the environment Safe if used properly Can harm wildlife and people Fig. 13-28, p. 295

27. Individuals Matter: Rachel Carson • Wrote Silent Spring which introduced the U.S. to the dangers of the pesticide DDT and related compounds to the environment. Figure 13-A

28. The ideal Pesticide and the Nightmare Insect Pest • The ideal pest-killing chemical has these qualities: • Kill only target pest. • Not cause genetic resistance in the target organism. • Disappear or break down into harmless chemicals after doing its job. • Be more cost-effective than doing nothing.

29. Superpests • Superpests are resistant to pesticides. • Superpests like the silver whitefly (left) challenge farmers as they cause > $200 million per year in U.S. crop losses. Figure 13-29

30. Pesticide Protection Laws in the U.S. • Government regulation has banned a number of harmful pesticides but some scientists call for strengthening pesticide laws. • The Environmental Protection Agency (EPA), the Department of Agriculture (USDA), and the Food and Drug Administration (FDA) regulate the sales of pesticides under the Federal Insecticide, Fungicide and Rodenticide Act (FIFRA). • The EPA has only evaluated the health effects of 10% of the active ingredients of all pesticides.

31. How Would You Vote? To conduct an instant in-class survey using a classroom response system, access “JoinIn Clicker Content” from the PowerLecture main menu for Living in the Environment. • Do the advantages of using synthetic chemical pesticides outweigh their disadvantages? • a. No. Synthetic pesticides are overused, damage the environment, and increase cancer risks. • b. Yes. Pesticides save human lives and protect crops.

32. What Can You Do? Reducing Exposure to Pesticides • Grow some of your food using organic methods. • Buy organic food. • Wash and scrub all fresh fruits, vegetables, and wild foods you pick. • Eat less or no meat. • Trim the fat from meat. Fig. 13-30, p. 299

33. Other Ways to Control Pests • There are cultivation, biological, and ecological alternatives to conventional chemical pesticides. • Fool the pest through cultivation practices. • Provide homes for the pest enemies. • Implant genetic resistance. • Bring in natural enemies. • Use pheromones to lure pests into traps. • Use hormones to disrupt life cycles.

34. Other Ways to Control Pests • Biological pest control: Wasp parasitizing a gypsy moth caterpillar. Figure 13-31

35. Other Ways to Control Pests • Genetic engineering can be used to develop pest and disease resistant crop strains. • Both tomato plants were exposed to destructive caterpillars. The genetically altered plant (right) shows little damage. Figure 13-32

36. Case Study: integrated Pest Management: A Component of Sustainable Agriculture • An ecological approach to pest control uses a mix of cultivation and biological methods, and small amounts of selected chemical pesticides as a last resort. • Integrated Pest Management (IPM)

37. Case Study: integrated Pest Management: A Component of Sustainable Agriculture • Many scientists urge the USDA to use three strategies to promote IPM in the U.S.: • Add a 2% sales tax on pesticides. • Establish federally supported IPM demonstration project for farmers. • Train USDA personnel and county farm agents in IPM. • The pesticide industry opposes such measures.

38. How Would You Vote? To conduct an instant in-class survey using a classroom response system, access “JoinIn Clicker Content” from the PowerLecture main menu for Living in the Environment. • Should governments heavily subsidize a switch to integrated pest management? • a. No. Without extensive funding and training, mere subsidies are not enough to successfully promote integrated pest management. • b. Yes. These subsidies would decrease pollution and exposure to hazardous pesticides.

39. SOLUTIONS: SUSTAINABLE AGRICULTURE • Three main ways to reduce hunger and malnutrition and the harmful effects of agriculture: • Slow population growth. • Sharply reduce poverty. • Develop and phase in systems of more sustainable, low input agriculture over the next few decades.

40. Solutions Sustainable Organic Agriculture More Less High-yield polyculture Soil erosion Soil salinization Organic fertilizers Aquifer depletion Biological pest control Overgrazing Overfishing Integrated pest management Loss of biodiversity Efficient irrigation Loss of prime cropland Perennial crops Food waste Crop rotation Subsidies for unsustainable farming and fishing Water-efficient crops Soil conservation Population growth Subsidies for sustainable farming and fishing Poverty Fig. 13-33, p. 302

41. Sustainable Agriculture • Results of 22 year study comparing organic and conventional farming. Figure 13-34

42. Solutions Organic Farming Improves soil fertility Reduces soil erosion Retains more water in soil during drought years Uses about 30% less energy per unit of yield Lowers CO2 emissions Reduces water pollution from recycling livestock wastes Eliminates pollution from pesticides Increases biodiversity above and below ground Benefits wildlife such as birds and bats Fig. 13-34, p. 302

43. Solutions: Making the Transition to More Sustainable Agriculture • More research, demonstration projects, government subsidies, and training can promote more sustainable organic agriculture. Figure 13-35

44. What Can You Do? Sustainable Organic Agriculture • Waste less food • Eat less or no meat • Feed pets balanced grain foods instead of meat • Use organic farming to grow some of your food • Buy organic food • Eat locally grown food • Compost food wastes Fig. 13-35, p. 303