1. Human Impact on the Environment:
Current Crises for Human Survival: Problems to be Solved Within the Next Generation
Practical observation of ONE example of human influence on the environment in the local area (e.g. the impact of alien species on biodiversity). Written report on the chosen example.
Look at the interrelatedness and interdependence of the human impacts and the environment.

3. Research: Human impact on the environment
Food security
Loss of Biodiversity
Climate change
Deforestation
Desertification
Discuss what you understand these terms to mean

4. The atmosphere and climate change
carbon dioxide emissions;
- concept of ‘carbon footprint’ and the need to
reduce the carbon footprint;
- deforestation;
- greenhouse effect and global warming:
desertification, drought and floods;
- methane emissions;
- ozone depletion.

5. http://www. vanderbilt

6. Non-natural sources of CO2
Burning fossil fuels for electricity
For transportation
South Africa is 13th in the world and 1st in Africa for CO2 emissions.

7. Carbon footprint: the amount of carbon dioxide or other carbon compounds emitted into the atmosphere by the activities of an individual, company, country.

8. Brainstorm what you can do to reduce your carbon footprint

9. Main greenhouse gases:
Carbon dioxide
Water vapour
Methane

10. Enhanced greenhouse effect (leads to global warming)

11. Methane emissions SOURCES:
Anaerobic respiration in the intestines of herbivores
Decomposition of organic waste
Treatment of waste water (sewerage)
Agricultural activities (e.g. rice paddies)
Mining
Making and using of fossil fuels and biofuels.

12. DEFORESTATION
Forests take out CO2 from the air. But we are cutting down forests for fuel, wood, paper, grazing space, roads, mining and agriculture. This results in less CO2 being removed from the atmosphere

13. We have to stop cutting down trees!* 
*This is getting really serious!*

14. Overgrazing on marginal lands (top) can extend desert zones (lower)
Desertification the productive potential of arid and semi-arid lands falls and topsoil is lost or degraded.
Desertification results mainly from a combination of natural climate changes causing prolonged drought and unsustainable human activities, including overgrazing and deforestation.
Desertification may lead to the formation of a desert or the encroachment of an existing desert onto formerly arable land.
Overgrazing on marginal lands (top) can extend desert zones (lower)

15. Effects of Climate Change
FLOODING

16. Effects of Climate Change
DROUGHT

17. Effects of Climate Change
Research what individuals, schools, communities and businesses can do to reduce climate change

18. EFFECTS OF CLIMATE CHANGE
See pg 336

19. OZONE DEPLETION
The ozone layer protects Earth from harmful UV radiation. However, it is getting thinner due to CFC’s.
CFC’s are released by refrigerators and aerosol cans.
EFFECTS:
Causes some trees to die → more greenhouse effect
Increased skin cancer
Can affect human immune systems.

20. HOW TO REDUCE CLIMATE CHANGE PG 339

21. Most household cleaning can be done with a half-and-half mixture of vinegar and water, or liquid soap
and baking soda.

23. How can your family/school reduce its electricity consumption?
If it has a thermostat it uses a large amount of electricity.
How can your family/school reduce its electricity consumption?

24. Ways to reduce climate change see pg 339.

28. Water:Availability: Construction of dams - Destruction of wetlands
- Poor farming practices
- Droughts and floods
- Exotic plantations and depletion of water table
- Boreholes and effects on aquifers
- Wastage
- Cost of water

32. South Africa gets about half the amount of rainfall that other countries receive.
Mostly arid

33. 1. CONSTRUCTION OF DAMS
Functions of dams: Stores water for human needs (residential, industrial and agricultural). Controls flood waters Can be used to generate hydro-power

34. NEGATIVES
Affects flow downstream, impacting on humans and the natural communities.

35. 2. DESTRUCTION OF WETLANDS

36. What is a wetland?
Wetlands are areas where terrestrial and aquatic ecosystems come together.
In a wetland, the water table is at or near the surface of the ground. The land is either temporarily or permanently covered with shallow water.

37. Wetlands are a source of water
Wetlands purify water .

38. DESTRUCTION OF WETLANDS
Destroyed by:
Draining the water
Filling with soil
Removing plants
(urbanisation)

40. 3. POOR FARMING PRACTICES
Water is needed for irrigation.
Much water however is lost through poor practices. E.g. Open ditch irrigation and ploughing along the slope.

41. 4. DROUGHTS AND FLOODS
Due to climate change, some areas will become drier and others wetter.
Floods and Droughts

42. 5. Exotic plantations and the depletion of the water table.
Exotic plantations can be beneficial financially.
Exotic plants have deeper roots and use more water than indigenous plants and thus deplete the water table
Exotic plantations

43. 6. Boreholes and effects on aquifers
Aquifer – permeable rock, saturated with water.
Boreholes remove water from aquifers and only precipitation and rivers can “recharge” these systems

44. 7. Wastage
Poor practices
Leaks

47. 8. Cost
6 kilolitres given free per household.

48. ACT pg 354 (exclude no2 )

49. Water: Quality
- Water for domestic use, industry, agriculture and mining: pollution, diseases, eutrophication and algal bloom.
- The effect of mining on quality of water
- Thermal pollution The need for water purification and recycling
- Alien plants, e.g., Eichornia

50. Uses of water
DOMESTIC: washing, cooking, cleaning, gardening, etc) INDUSTRIAL USES: parts of ingredients, to cool down machinery. AGRICULTURAL: Drinking water for livestock and watering (irrigation) After being used water is polluted.

51. WATER POLLUTION
Domestic pollutants: detergents and pathogenic bacteria from sewage. Industrial pollutants: heavy metals, paints solvents, oil, heat Agricultural pollutants: pesticides, herbicides and fertilisers.

52. EUT ROPHICATION
Excess fertilisers → water system → nutrients (N and P) → rapid growth of algae (algal blooms) →Block sunlight → plants die → decomposition → oxygen is used up → animals die.

54. EFFECT OF MINING
Releases acidic water with a high temperature (thermal pollution) which contains heavy metals (poisonous).

55. THERMAL POLLUTION Increased temperature of water.
Some benefit, but others negatively affected, because warm water has less O2. Warm waters more likely to get algal blooms.

57. EFFECT OF ALIEN PLANTS
Some alien species grow out of control (invasive). No natural predators/parasites → outcompete indigenous species.
Water hyacinth (Eichhornia crassipes)can form a continuous layer blocking light. The impact is similar to that of algal blooms.
They also prevent recreational activities.
It cost millions of rands to clear them from the water.