1. How does deforestation impact people and the environment?

2. Recap Causes of deforestation
Agricultural activities
Cattle ranching
Logging
Mining 1 2 3 4

3. Tropical Rainforest
What are tropical rainforests and where are they found?
What are the uses of tropical rainforest?
What is deforestation?
Why does deforestation occur?
How does deforestation impact people and the environment?
How should we manage deforestation?

4. Tropical Rainforest
What are tropical rainforests and where are they found?
What are the uses of tropical rainforest?
What is deforestation?
Why does deforestation occur?
How does deforestation impact people and the environment?
How should we manage deforestation?

5. Lesson Objective
Describe the impact of deforestation on people and the environment.

6. Impacts of deforestation
Environmental
- Loss of biodiversity
- Loss of water catchment areas
- Increased risk of flooding, soil erosion and sedimentation
- Enhanced greenhouse effect
Economic
- Depletion of natural resources
Social
- Effects on indigenous people

7. Pair Activity In pairs fill up the worksheet as follow:
Environmental Impact
Economic Impact
Social Impact
Loss of biodiversity
Loss of water catchment
Increased risk of flooding with soil erosion and sedimentation
Depletion of natural resources
Effect on indigenous people
2 pairs
3 pairs
In pairs fill up the worksheet as follow:
State the type of impact
State the name of factor
Describe the impact of deforestation on people and the environment

8. Enhanced greenhouse effect
The earth’s atmosphere keeps the earth warm enough for us to live.
When the sun’s rays pass through the atmosphere and strike the surface of the earth, part of the heat is absorbed by the earth.
The rest of the heat is reflected back into the atmosphere, towards space.
A greenhouse is a building made of glass, where you grow plants that need protection from cold weather. The glass allows sunlight to shine in and warm the plants and air during the day. At night, the heat is trapped by the glass and is prevented from escaping. Therefore, the greenhouse remains warm even in cold weather.

9. Enhanced greenhouse effect
As heat passes through the atmosphere, greenhouse gases (e.g. carbon dioxide, methane, water vapour and some other gases) in the atmosphere trap some of the heat and prevent it from escaping into space.
This causes the warming of the atmosphere and is known as the greenhouse effect.

10. Enhanced greenhouse effect
Without the greenhouse effect, the earth’s average temperature will be −18°C rather than the current 15°C.
However, the amount of greenhouse gases in the atmosphere has increased because of human activities.
This has led to a rise in the earth’s average temperature as more heat is trapped in the atmosphere  Enhanced greenhouse effect

12. Enhanced greenhouse effect
Deforestation is one of the human activities contributing to the enhanced greenhouse effect.
Deforestation increases the amount of carbon dioxide in the atmosphere.
Scientists estimate that about 4.8 billion tonnes of carbon dioxide are absorbed by tropical rainforests every year where the Amazon rainforest is the biggest store of carbon.

13. Enhanced greenhouse effect
The top 10 contributors to greenhouse gas emissions due to deforestation. More than half of the carbon dioxide released is from Brazil and Indonesia, where large areas of tropical rainforests are found.
Deforestation of tropical rainforest contributes significantly to the total amount of carbon dioxide released into the atmosphere

14. Enhanced greenhouse effect
The enhanced greenhouse effect affects people and the environment.
For example:
Increased temperatures can cause ice caps to melt.
Results in a rise in sea levels and flooding of low-lying coastal areas.
Low-lying islands (Kiribati and Vanuatu in the Pacific Ocean) may be submerged and disappear into the sea.
As such, people living on these islands may lose their homes.

15. Pair Activity In pairs fill up the worksheet as follow:
Environmental Impact
Economic Impact
Social Impact
Loss of biodiversity
Loss of water catchment
Increased risk of flooding with soil erosion and sedimentation
Depletion of natural resources
Effect on indigenous people
2 pairs
3 pairs
In pairs fill up the worksheet as follow:
State the type of impact
State the name of factor
Describe the impact of deforestation on people and the environment

16. Homework
Fill up the worksheets according to the factors given to you. Due: Tomorrow 31st March (Tuesday) Will select 1 pair from each factor to present.

17. How does deforestation impact people and the environment?

18. Impacts of deforestation
Environmental
- Loss of biodiversity
- Loss of water catchment areas
- Increased risk of flooding, soil erosion and sedimentation
- Enhanced greenhouse effect
Economic
- Depletion of natural resources
Social
- Effects on indigenous people

19. Loss of biodiversity

20. Loss of Biodiversity
Deforestation destroys the habitats of plants and animals.
Loss of biodiversity = Loss of the variety of plants and animals.
Millions of plant and animal species have become extinct.
As a result, there is lesser variety of resources that we can obtain from the rainforest.

21. Loss of Biodiversity
Plants of medicinal value are lost when a single tree is cut down in a tropical rainforest.
Imagine the loss when thousands of trees are cut down every day!
Pg 98

22. Loss of Biodiversity
Changes in biodiversity may increase the likelihood of insect-borne diseases (e.g. malaria, dengue fever) due to the lack of predators to control the population.
The rainforest may grow back (but often not) after being deforested and if it does, the lack of nutrients in the soils may not be able to support the biodiversity that once existed on that land.

23. Loss of water catchment areas

24. Loss of water catchment areas
Forests play an important role in maintaining our water supply.
They enable water to be collected and stored within a water catchment area.
The Amazon Basin is said to produce half of its rainfall through the forest’s transpiration process in the water cycle.

25. Loss of water catchment areas

26. Loss of water catchment areas
The Amazon Basin has 7,000 tributaries
Countries surrounding the Amazon rainforest depend on water from the Amazon Basin, especially during dry seasons.

27. Loss of water catchment areas
Mass clearing of trees disrupts the water cycle.
When trees are removed, a drier climate and drier soils might occur as the ground no longer contains and receives as much water.
In turn, this results in decreased water supply and higher water prices.
In Tanzania, deforestation caused by charcoal production is predicted to reduce ½ of its catchment area by The cost of water is expected to rise by four times!

28. Increased risk of flooding, soil erosion and sedimentation

29. Increased risk of flooding, soil erosion and sedimentation
When trees are cleared, the ground is left bare.
Rainwater falls directly on the ground and flows over the surface more rapidly as surface runoff.
This causes flooding in the surrounding areas.

30. Increased risk of flooding, soil erosion and sedimentation
Interception
Infiltration

31. Increased risk of flooding, soil erosion and sedimentation
Soil erosion is the removal of the top layers of soil by rainwater, wind and destructive human activities (logging).
When the trees are removed, land becomes exposed.
Water washes the soil away when it rains.

32. Increased risk of flooding, soil erosion and sedimentation
The Great Red Island in Madagascar has lost so much soil to erosion (400 tonnes for every 0.01 km2) that its rivers are blood-red, affecting even the surrounding Indian Ocean.

33. Increased risk of flooding, soil erosion and sedimentation
Eroded soil is often washed into rivers, increasing the amount of sediments in the rivers.
This affects water quality and aquatic life.
The increased amount of sediments smothers fish eggs, resulting in lower hatch rates.
Also, it turns water cloudy and prevents sunlight from penetrating the water.

34. Increased risk of flooding, soil erosion and sedimentation
Sediments enter
the sea
Coral reefs get suffocated
Sediments will eventually settle and accumulate

35. Impacts of deforestation
Environmental
- Loss of biodiversity
- Loss of water catchment areas
- Increased risk of flooding, soil erosion and sedimentation
- Enhanced greenhouse effect
Economic
- Depletion of natural resources
Social
- Effects on indigenous people

36. How does deforestation impact people and the environment?

37. Impacts of deforestation
Environmental
- Loss of biodiversity
- Loss of water catchment areas
- Increased risk of flooding, soil erosion and sedimentation
- Enhanced greenhouse effect
Economic
- Depletion of natural resources
Social
- Effects on indigenous people

38. Depletion of natural resources

39. Depletion of natural resources
Natural resource: Anything from the natural environment that people can use to satisfy their needs such as food, shelter, clothing, air and water.
Tropical rainforests provide important natural resources (timber, food and water) that contribute greatly to the economic growth of many countries.
Rapid deforestation often destroys the rainforest faster than it can replenish itself.

40. Depletion of natural resources
Earnings of industries that rely on rainforest resources get affected
e.g. timber trade.

41. Effects on indigenous people

42. Effects on indigenous people
The Guarani community is living in makeshift camps because parts of the forest were cleared for sugarcane plantations, displacing these people from their homes in the tropical rainforest.

43. Effects on indigenous people
Cutting down rainforests to create land for plantations or mining affects the lives of indigenous people.
They lose their homes and are forced to adapt to a new way of living to survive.
Traditionally, they live in harmony and obtain everything they need (food, shelter) from the forest.
This displacement often causes indigenous tribes to disperse and cultures to disappear.

44. Effects on indigenous people
The impact of deforestation can be devastating.
However, people have different views towards this issue

45. Effects on indigenous people
Palm oil production in Sarawak, Malaysia
Malaysia is the world’s second largest producer of palm oil.
Currently, 40,000 km2 of the land in Peninsular Malaysia are planted with oil palms.
New plantations have sprouted in Sarawak as land is used up in Peninsular Malaysia.
In 2010, Sarawak was predicted to become Malaysia’s largest palm oil producer by the end of this decade.

46. Impacts of deforestation
Summary
Impacts of deforestation
Environmental
- Loss of biodiversity
- Loss of water catchment areas
- Increased risk of flooding, soil erosion and sedimentation
- Enhanced greenhouse effect
Economic
- Depletion of natural resources
Social
- Effects on indigenous people

47. Homework: Workbook: Activity 3.3: Page 41-42 Activity 3.4: Pages 43-45