Humans in the Biosphere

1. Humans in the Biosphere Chapter 6

2. Changing Landscape Activities affect environment Relationship between resources and sustainable use

3. Effect of Human Activity • Living on Island Earth • We affect environment when: • Obtain food • Eliminate waste products • Build places to live • Humans impact regional and global environments: • Agriculture • Development • Industry Which impact natural resources such as soil, water and the atmosphere.

4. Effect of Human Activity Agriculture • Dependable supply of food that can be stored for future use • Monoculture-clearing large areas of land to plant a single highly productive crop annually (soybean) • Efficient sowing , tending, and harvesting of crops • Providing food for nearly 7 billion people-impacts natural resources • Fertilizer production and Farm machinery-consume large amounts of fossil fuels.

5. e.g.-Canola Oil Soybean

6. Effects of Human Activity • Development • Dense human communities produce lots of wastes. • Not disposed correctly they affect air, water and soil. • Consumes farmland • Habitat fragmentation

7. Effects of Human Activity • Industrial Growth • Conveniences utilize a great deal of energy to produce and power • Energy comes from burning fossil fuels such as coal, oil and natural gas (emits greenhouse gases-90 % of US emissions) • Past-dumped waste directly into air, water and soil

8. Sustainable development • Goods-things that can be bought and sold and have value in terms of dollars and cents. • Services-processes or actions that produce goods. • Ecologically-these are goods and services produced by ecosystems that benefit the human economy.

9. What type of goods and service?

10. Ecosystem Goods and Services • Many natural and free of charge • Breathable air • Drinkable water • In environment cant provide-society must spend money to produce • E.g. many places drinkable water is free; source polluted or damages and water quality falls-must pay for water treatment to be safe.

12. Renewable and Nonrenewable Resources Renewable Nonrenewable Natural processes cannot replenish these goods within a reasonable amount of time. E.g. fossil fuels (formed from buried organic material over millions of years) ; when depleted they are gone. • Can be produced or replaced by healthy ecosystem. • E.g. southern white pine that can grow back when an old tree dies or is cut down.

14. Sustainable Resource Use • Conscious Way to use resources • Provides for human needs while preserving the ecosystem that produce natural resources • No harm to soil, water or climate • Flexible enough to survive environmental stresses (droughts, floods, heat waves, etc.) • Human economic systems-more than just enable people to survive-must help situation.

16. Using Resources Wisely

17. Soil Resources • Important objects that rely on soil • Grain in cereal • Wood in home • Pages of textbook • Healthly soil supports agriculture and forestry.

18. Topsoil- mineral- and nutrient- rich portions of soil • GOOD • absorbs and retains moisture • allows draining • rich organic matter and nutrients • Renewable Resource • Properly managed • Healthy soil can take centuries to forms but be lost quickely

19. 1930s drought • Badly eroded once-fertile soil of Great Plains • Thousands lost jobs and homes • Became a desert w/ dry soil- aka “dust bowl” • Cause-conversion of prairie land to cropland in way that left soil vulnerable to erosion (wearing away).

20. Soil Erosion • Removal of soil by water or wind • Worse- land plowed and left barren b/w plantings. • No roots to hold soil-easily washed away • Badly eroded-organic materials and minerals that make soil fertile are carried away.

21. Desertification • Dry climates-farming, overgrazing, seasonal drought and climate change can turn farmland to desert. • Great Plains is an example • 40% of Earth’s land is considered at risk

22. Desertification Risk

23. Deforestation • Loss of forest • Forests value • Wood • Hold soil in place • Protect quality of water • Absorb CO2 • Moderate local temperature

24. Deforestation • ½ of world’s old-growth forests (never been cut) lost • Temperate areas-forest can regrow after cutting; centuries for succession • Tropics-forest DO NOT grow back after logging • Old-Growth forest usually considered non-renewable.

25. Deforestation can: • Leads to severe erosion • Change local soils and microclimates in a way prevent regrowth of trees • E.g Tropical Rain Forest- • Soil is thin and decomposition quick b/c of high heat and humidity. • Soil ok for few years • Then becomes wasteland; harsh conditions prevent regrowth

26. Soil use and sustainability • Minimize erosion through careful management of both agricultural and forestry • Leaving stems and roots can help • Crop rotation-planting different crops at different seasons or in different years (erosion and nutrient loss) • Altering shape (e.g. planting fields across, instead of down and slope; reduce water runoff and erosion.

27. Freshwater Resources • Goods and services-drinking water, industry, transportation, energy and waste disposal. • Fresh water is renewable resource; some is not • Ogallala Aquifer- spans 8 states (South Dakota to Texas); more than a million years to collect; not replenished by rainfall; expected to run dry in 20-40 years. • 3% Earth’s water is fresh water- most locked in ice at poles

28. Water Pollution • Pollutant-harmful material that can enter biosphere. • Point source- pollution enter water supply from single source (e.g. factory or oil spill) • Nonpoint source- pollutant enters from many smaller sources (e.g. grease and oil washed off streets; chemicals released by factories and autos) • Primary sources-industrial and agriculture chemicals; residential sewage; and nonpoint sources

29. Industrial and Agricultural Chemicals Industrial Chemicals Agricultural Chemicals Pesticides and insecticides Runoff-enter water supply DDT-pesticide; dangerous, controls against pest and disease carrying mosquitoes; threatened fish-eating birds-females laid fragile eggs; lowered numbers Biomagnification • PCBs-Chemical used in industry until 1970s; large-scale contamination events; banned. • Can be difficult, if not impossible to eliminate • Others-Cadmium, lead, mercury and zinc

30. Biological Magnification Pollutant concentrations increase as they move up the trophic levels.

31. DDT (dichlorodiphenyltrichloroethane)

32. Residential Sewage • Household waste-becomes sewage • Not poisonous-contains lots of nitrogen and phosphorus • Reasonable amounts-process and absorbed healthy ecosystem • Large amounts-blooms of algae and bacteria rob water of oxygen. • Dead zones-oxygen poor areas- fresh or salt water • Sewage carry microorganism that can spread disease.

33. Water Quality and Sustainability • Protect natural systems involved in water cycle. • Watershed-land whose groundwater, streams, and rivers drain into same place (lake or river) • Sewage treatment can lower bacteria and prevent dead zones • Integrated Pest Management (IPM) instead of pesticides-biological control

34. Water Quality and Sustainability • Use of less-poisonous sprays • Crop rotation • Water conservation • drip irrigation

35. Atmospheric Resources Common resource whose quality has a direct effect on health *Provides Oxygen we breathe

36. Ozone Form of oxygen-O3 Natural; Upper atmosphere Absorbs harmful UV radiation from sunlight; protecting skin from cancer

37. Atmospheric Services • Greenhouse Gases- (CO2, Methane and water vapor) regulate global temperatures • W/out Earth would be 30°C cooler • Never “Used Up” • Human activities can have lasting impact

38. Air Pollution • Air quality reduced-respiratory illnesses are made worse and tend to increase. • Globally-climate patterns may be impacted

39. Cause of Air Pollution • Industrial processes • Burning fossil fuels

40. Forms of Air Pollution • Smog • Acid Rain • Greenhouse Gases • Particulates

41. Smog • Gray-brown haze formed by chemical reactions among pollutants released into the air by industrial processes and automobile exhaust.

42. Smog • Products • Ozone-High in atmosphere protective; ground level, threatens health, especially those with respiratory conditions. • 2008 summer Olympics in Beijing

43. Acid Rain • Rain containing nitric and sulfuric acids • Cause-burning fossil fuel releases nitrogen and sulfur compounds; combine with water vapors and from acids. • Effects • kills plants • Damages leaves • Changes chemistry of the soil and surface water • Dissolve and release mercury and other toxic elements from soil (enter other parts of biosphere)

45. Greenhouse Gases • Burning fossil fuels and forest-release carbon into atmosphere as CO2 • Agriculture-raising cattle to farming rice releases methane and other green house gasses. • Contribute to global warming and climate change.

46. Particulates • Visible, microscopic particles from certain industrial processes and certain diesel engines. • Ash, dust, soot, smoke aerosols • Enter nose and mouth-to lungsand cause serious health problems.

47. Air Quality and Sustainability • Difficult to improve • Doesn’t stay in one place • Doesn’t “belong” to anyone • Improvements • Automobile emissions standards • Clean-air regulations • Phasing out of lead gas; now banned in US

48. Complete: Analyzing Data, page 164.

49. Biodiversity Total of all the genetically based variation in all organisms in the biosphere Variety of organisms

50. Types of Biodiversity • Ecosystem Diversity-Variety of habitats, communities and ecological processes in the biosphere. • Species Diversity- The number of different species in the biosphere or in a particular area. • 1.8 species identified and named • 30 million more to be discovered • Genetic Diversity-Sum total of all different forms of genetic information carried by a particular species, or all organisms on Earth.