1. Do Now: Identify and discuss 2 factors that may limit food production in the future.

2. Turn and Talk Can we survive without soil?

3. Aim: What Environmental Problems Arise from Food Production?

4. Producing Food Has Major Environmental Impacts Harmful effects of agriculture on Biodiversity Soil Water Air Human health

5. Natural Capital Degradation: Food Production Fig. 12-10, p. 289

6. Natural Capital Degradation Food Production Biodiversity LossSoilWaterAir PollutionHuman Health Loss and degradation of grasslands, forests, and wetlands in cultivated areas ErosionWater wasteEmissions of greenhouse gas CO 2 from fossil fuel use Nitrates in drinking water (blue baby) Loss of fertility Aquifer depletion Pesticide residues in drinking water, food, and air Salinization Increased runoff, sediment pollution, and fl ooding from cleared land Emissions of greenhouse gas N 2 O from use of inorganic fertilizers Fish kills from pesticide runoff Waterlogging Contamination of drinking and swimming water from livestock wastes Killing wild predators to protect livestock Desertification Pollution from pesticides and fertilizers Emissions of greenhouse gas methane (CH 4 ) by cattle (mostly belching) Increased acidity Loss of genetic diversity of wild crop strains replaced by monoculture strains Algal blooms and fish kills in lakes and rivers caused by runoff of fertilizers and agricultural wastes Bacterial contamination of meat Other air pollutants from fossil fuel use and pesticide sprays

7. Do you understand how the envrionment is degraded?

8. Topsoil Erosion Is a Serious Problem in Parts of the World Soil erosion Movement of soil by wind and water Natural causes Human causes Two major harmful effects of soil erosion Loss of soil fertility Water pollution

9. Topsoil Erosion on a Farm in Tennessee Fig. 12-11, p. 289

10. Natural Capital Degradation: Gully Erosion in Bolivia Fig. 12-12, p. 290

11. Wind Removes Topsoil in Dry Areas Fig. 12-13, p. 290

12. Natural Capital Degradation: Global Soil Erosion Fig. 12-14, p. 291

13. Serious concern Some concern Stable or nonvegetative

14. Drought and Human Activities Are Degrading Drylands Desertification: productive potential of topsoil fails Moderate (10-25% drop) Severe (25-50% drop) Very severe (over 50% drop) Human agriculture accelerates desertification Effect of global warming on desertification

15. Severe Desertification Fig. 12-15, p. 291

16. Natural Capital Degradation: Desertification of Arid and Semiarid Lands Fig. 12-16, p. 292

17. Do you understand how soil erosion leads to desertification?

18. Excessive Irrigation Has Serious Consequences Salinization Gradual accumulation of salts in the soil from irrigation water Lowers crop yields and can even kill plants Affects 10% of world croplands Waterlogging Irrigation water gradually raises water table Can prevent roots from getting oxygen Affects 10% of world croplands

19. Natural Capital Degradation: Severe Salinization on Heavily Irrigated Land Fig. 12-17, p. 292

20. Agriculture Contributes to Air Pollution and Projected Climate Change Clearing and burning of forests for croplands One-fourth of all human-generated greenhouse gases Livestock contributes 18% of gases: methane in cow belches Grass-fed better than feedlots

21. Food and Biofuel Production Systems Have Caused Major Biodiversity Losses Biodiversity threatened when Forest and grasslands are replaced with croplands – tropical forests Agrobiodiversity threatened when Human-engineered monocultures are used Importance of seed banks Newest: underground vault in the Norwegian Arctic

22. Genetic Engineering Could Solve Some Problems but Create Others Pros Cons

23. Fig. 12-18, p. 294 Trade-Offs Genetically Modified Crops and Foods AdvantagesDisadvantages Need less fertilizer Unpredictable genetic and ecological effects Need less water Harmful toxins and new allergens in food More resistant to insects, disease, frost, and drought No increase in yields Grow faster More pesticide-resistant insects and herbicide-resistant weeds May need less pesticides or tolerate higher levels of herbicides Could disrupt seed market May reduce energy needs Lower genetic diversity

24. There Are Limits to Expanding the Green Revolutions Usually require large inputs of fertilizer, pesticides, and water Often too expensive for many farmers Can we expand the green revolution by Irrigating more cropland? Improving the efficiency of irrigation? Cultivating more land? Marginal land? Using GMOs? Multicropping?

25. Industrialized Meat Production Has Harmful Environmental Consequences Advantages Disadvantages

26. Trade-Offs: Animal Feedlots Fig. 12-19, p. 295

27. Trade-Offs Animal Feedlots AdvantagesDisadvantages Large inputs of grain, fish meal, water, and fossil fuels Increased meat production Greenhouse gas (CO 2 and CH 4 ) emissions Higher profits Less land use Reduced overgrazing Concentration of animal wastes that can pollute water Reduced soil erosion Use of antibiotics can increase genetic resistance to microbes in humans Protection of biodiversity

28. Producing Fish through Aquaculture Can Harm Aquatic Ecosystems Advantages Disadvantages

29. Fig. 12-20, p. 296 Trade-Offs Aquaculture AdvantagesDisadvantages Large inputs of land, feed, and water High efficiency High yield Large waste output Reduced over- harvesting of fisheries Loss of mangrove forests and estuaries Some species fed with grain, fish meal, or fish oil Low fuel use Dense populations vulnerable to disease High profits

30. Summary: Do the advantages of industrialized farming and aquaculture outweigh the disadvantages? Support your answer using evidence from case studies.