ENVIRONMENTAL HAZARD II AND III Lesson note

PROPOSED LESSON PLAN/NOTE FOR THE FIRST WEEK ENDING 13th SEPTEMBER, 2022/2023 ACADEMIC SESSION

SUBJECT: BASIC SCIENCE

TOPIC: ENVIRONTAL HAZARD II AND III

CLASS: GRADE 9

NUMBER OF STUDENTS: 15

AVERAGE AGE: 13+ YEARS

GENDER: MIXED


PERIOD: 3RD&4TH PERIOD ON MONDAY AND WEDNESDAY RESPECTIVELY

DURATION: 40 MINUTES

DATE: 12/09/2022

SPECIFIC OBJECTIVES: By the end of the lesson the students should be able to;

i. explain deforestation-Reasons For Deforestation, Effects On The Environment, Regulations On Deforestation.

ii. discuss desertification-Meaning, Geographical Area, Causes And Control Measures.

iii. explain Ozone Layer Depletion-Causes Effects And Control Measures.

ENTRY BEHAVIOUR: Students are familiar with forest.

INSTRUCTIONAL MATERIALS: Textbook, lesson note, laptop, projector, marker, whiteboard, Pictures showing forest, desert, ozone layer.

INSTRUCTIONAL METHODS/TECHNIC: Questions, simulation, quiz.

INTRODUCTION: Questions posed to the students include:

Question 1: Have you seen a forest before?

Expected Answer: Yes

Question 2: Why do people clear forest?

Expected Answer: For building, planting.

STEP I: MEANING OF DEFORESTATION

  The clearing of large areas of forests by man is termed deforestation. Forest refers to a large area of land covered with trees. Forests support thousands of  

Life forms of plants and animals.

REASONS FOR DEFORESTATION:

1. Fire wood gathering for domestic purposes.

2. Increased demand for housing.

3. Expansion of agricultural land.

4. Mining activities.

5. Industrial/ Commercial Activities.

6. Overgrazing

7. Natural disaster such as forest fires.

Question 3: What is the effects deforestation on the environment?

 Expected Answer: Global warming

EFFECTS OF DEFORESTATION ON THE ENVIRONMENT:

1. Global warming and greenhouse effect: Global warming is a sustained increase in the average temperature of the Earth, sufficient to cause climate change. The trees remove carbon dioxide from the atmosphere during the process of photosynthesis and release oxygen back into the atmosphere. Greenhouse is a hot state in global climate. Deforestation contributes to global warming, and is often cited as one of the major causes of the enhanced greenhouse effect.

2. Disturbance in water cycle: When a part of a forest is removed, the trees are no longer available to evaporate water present in them, resulting in a drier climate. Deforestation reduces the content of water in the soil and groundwater as well as atmospheric moisture.

3. Biodiversity: Deforestation generally increases the rate of soil erosion, by increasing the amount of runoff and reducing the protection of the soil from tree litter.

4. Rate of soil erosion: Deforestation generally increases the rate of soil erosion, by increasing the amount of runoff and reducing the protection of the soil from tree litter.

5. Economic impact: Any damage to forests and other aspects of nature could harm the living standards of the population which is dependent on forests for its living.

REGULATION ON DEFORESTATION:

1. Involvement of Local People: Local people should be involved in the conservation of forest.

2. Use of Alternative Source of Energy: Renewable energy such as hydel, tidal and solar energy should be used.

3. Afforestation: Forest areas should be increase by massive plantation of trees on the degraded land.

4. Legislation: Laws should be made and implemented strictly to check the following;

i. Prevention of overgrazing.

ii. Appointment of forest guards to prevent any illegal activity in forests.

iii. Restriction on mining on any forest land.

iv. Deforestation.

STEP II: DESERTIFICATION-MEANING, GEOGRAPHICAL AREA, CAUSES AND CONTROL MEASURES.

MEANING OF DESERTIFICATION: Desertification simply means making of deserts. It may be because of loss of vegetation, little or no rainfall, high temperature, etc. Desertification is the gradual conversion of fertile land into desert usually as a result of human activities.

EFFECTS OF DESERTIFICATION:

i. Loss of topsoil by soil erosion due to bad management of farmland.

ii. After desertification, the land cannot be used to grow crops or support livestock

iii. Loss of vegetation and exposure of soils to the atmosphere create warmer and drier climates. It further leads to desertification.

GEOGRAPHICAL ZONES PRONE TO DESERTIFICATION:

Areas having less or no rainfall are more prone to become deserts. In Northern states such as Katsina, Kano, Sokoto, Jigawa, Borno, have very low rainfall.  

CAUSES OF DESERTIFICATION:

i. Misuse of resources.

ii. Overgrazing which makes the land barren.

iii. Deforestation which leads to soil erosion until the land can no longer be used to grow crops.

iv. Cutting of trees for firewood makes the land arid.

 v. Over cultivation of crops on the same land resulting in loss of fertility rendering it unsuitable for cultivation.

vi. Bush burning exposes the soil to wind and rain.

vii. Bad management of farmland by the farmers.

CONTROL MEASURES OF DESERTIFICATION:

1. Sustained planting of trees.

2. Strict regulations against cutting of trees.

3. Spreading awareness in local people about the benefits of planting trees.

4. Regulation against bush burning.

STEP III: DEPLETION OF OZONE LAYER AND ITS EFFECTS

DESCRIPTION OF OZONE LAYER

  The Earth’s atmosphere consists of a number of different layers i.e. troposphere, stratosphere, mesosphere, thermosphere and Exosphere. The stratosphere contains the ozone shield, a layer of ozone (O3). Ozone layer shields the surface from biologically destructive ultraviolet radiation from the sun. Ozone is being destroyed by the release of gases particularly chlorofluorocarbons (CFCs). CFCs are used in refrigerators, solvents, and air conditioners.

LOCATION OF THE OZONE LAYER IN THE ATMOSPHERE:

 Earth’s atmosphere is made up of a number of different layers. The troposphere which is the lower atmospheric layer surrounds us at ground level. The stratosphere is often called the upper atmosphere.

Ozone lies above the troposphere and extends between 8 km to 50 km. It is produced in the upper atmosphere when sunlight strikes oxygen atoms and causes them to temporarily combine. It performs a very important function as it shields the atmosphere and protects the earth from ultraviolet (UV) radiation. The UV radiation is very harmful and highly damaging.

IMPORTANCE OF OZONE LAYER:

Ultraviolet radiations are very harmful or highly damaging to us. The ozone layer serves as an umbrella or protective shield that saves the Earth's surface from most of the ultraviolet solar radiation.

EFFECTS OF DEPLETION OF THE OZONE LAYER TO THE LIFE ON EARTH:

1. Greenhouse Effect: The greenhouse effect is a natural process in which certain gases, known as "greenhouse gases," trap heat that radiates from the earth's surface. The temperature on Earth may increase by about 1.5 to 4.5°C by the year 2050. Photosynthesis, water use efficiency and yield of plants would decrease. The photosynthesis by phytoplankton in the aquatic ecosystem would also be markedly reduced. Human health is also affected.

2. Global Warming: All scientists agree that if "greenhouse gases" increase and all other factors remain constant, the Earth will warm up. The climate is getting warmer and the effects of global warming are becoming increasingly noticeable in many countries.

3. Ice Melting and Flooding: According to most estimates, a 20C average increase in global temperature would warm up the Antarctic by 50C. This temperature rise is enough for the melting and disintegration of ice-sheets. This will increase sea level by 16 to 20 feet. It will cause flooding in most of the areas.

CONTROL MEASURES TO PREVENT DEPLETION OF OZONE LAYER:

1. Reduce bush burning.

2. By reducing the use of CFCs. Many countries have already banned the use of CFCs.

3. By developing substitutes to replace CFCs. Scientists have already developed some substitutes which are ozone friendly.

4. Reduction of energy use, especially the fossil fuels.

5. Shifting from carbon-based fossil fuels to alternative energy sources.

6. Carbon capture and storage.

7. Geoengineering including carbon sequenstation.

SUMMARY/CONCLUSSION:

i. Desertification refers to sustained land degradation.

ii. Desertification results from the misuse of resources. Desertification can be controlled by the systemic and sustained planting of trees.

EVALUATION: Oral questions

1. What is desertification?

2. What are the causes and effects of desertification?

3. What is deforestation?

4. What is ozone layer? Where is it present?

5. What is ozone hole? How is it formed?

ASSIGNMENT:

1. Discuss the role of laws and regulations in the prevention of deforestation.

2. Name two agencies, which can make laws and regulations on bush burning.

3. List any two reasons for deforestation.

4. What are the harmful effects of the ozone layer depletion?

5. List some of the control measures to prevent depletion of ozone layer.

Post a Comment

0 Comments