Global warming and ozone depletion are caused by human activities like the release of greenhouse gases and chlorofluorocarbons. Greenhouse gases trap heat in the atmosphere, causing the surface and lower atmosphere to warm. This warming affects people through rising sea levels, increased tropical diseases, and dehydration. Ozone depletion occurs when chlorine atoms destroy ozone molecules in the ozone layer, allowing more ultraviolet radiation to reach the Earth's surface and increasing health risks like cataracts. International agreements like the Montreal Protocol aim to reduce ozone-depleting substances to mitigate these issues.

1. Earth: Our Home 2 (S/E and N(A))
QUESTION BANK Chapter 10
CHAPTER 10: GLOBAL WARMING
AND OZONE DEPLETION
Multiple-choice Questions (15 marks)
1. What is the ‘greenhouse effect’?
A The Sun’s rays warm the Earth’s surface and lower atmosphere.
B When haze combines with water vapour, the Earth’s surface
and lower atmosphere get warm.
C Gases that trap the Sun’s rays cause the warming of the Earth’s
surface and lower atmosphere.
D The gases in the Earth’s atmosphere warm the Earth’s surface
and lower atmosphere.
Ans: C
2. Why is the greenhouse effect important?
A This allows all living things to live in an environment that has a
constant temperature.
B This allows green plants to survive and to photosynthesise and
produce food.
C This allows plants that can only be grown in a greenhouse to
survive temperature fluctuations.
D This allows all living things to survive in an environment that is
not too hot or too cold.
Ans: D
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2. Earth: Our Home 2 (S/E and N(A))
QUESTION BANK Chapter 10
3. Study the photograph below. Why is the use of this substance one of
the causes of global warming?
A The liquids that are released cause more heat to be trapped in
the atmosphere.
B The gases that are released cause the Earth’s surface to heat
up faster.
C The liquids that are released cause the Earth’s atmosphere and
surface to heat up.
D The gases that are released cause more heat to be trapped in
the atmosphere.
Ans: D
4. Study the photograph below. What are the gases that are released
through this human activity?
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3. Earth: Our Home 2 (S/E and N(A))
QUESTION BANK Chapter 10
A Sulphur dioxide and methane
B Methane and nitrous oxide
C Carbon dioxide and carbon monoxide
D CFCs and carbon dioxide Ans: B
5. What is the impact of global warming on plants?
A In colder regions, a warmer climate may allow people to grow
new crops.
B Global warming generally encourages plant growth as
temperatures are higher.
C Plants are affected by diseases that are brought about by high
temperatures.
D Production of food crops increases due to higher temperatures.
Ans: A
6. How are people affected by global warming?
I. More people catch pneumonia.
II. There is an increase in tropical diseases.
III. More people develop eye cataracts.
IV. More people suffer from dehydration.
A I and II
B II and IV
C II, III and IV
D All of the above Ans: B
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4. Earth: Our Home 2 (S/E and N(A))
QUESTION BANK Chapter 10
7. Study the photograph below. How does global warming affect people
living in places such as the one in the photograph?
A Rising temperatures can cause sea levels to rise and flood the
coastal areas.
B Coastal waters freeze and cause ice sheets to form and cover
the coastal areas.
C Global warming triggers tsunamis which then flood and destroy
the coastal areas.
D Coastal areas are reduced when the land mass shrinks due to
global warming.
Ans: A
8. How does ozone depletion occur?
A It occurs when oxygen atoms are added to ozone molecules.
B It occurs when carbon atoms destroy ozone molecules in the
ozone layer.
C It occurs when sulphur dioxide attacks ozone molecules in the
ozone layer.
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5. Earth: Our Home 2 (S/E and N(A))
QUESTION BANK Chapter 10
D It occurs when chlorine atoms destroy ozone molecules in the
ozone layer.
Ans: D
9. Which one of the following is an example of substances that cause
ozone depletion?
A Old television sets
B Insulation packaging
C Gas heater
D Computer monitor Ans: B
10. What is the function of the ozone layer?
A It helps to prevent the Earth from cooling down.
B It helps to protect us from rises in temperature.
C It helps to protect us from harmful ultraviolet rays.
D It helps to keep the Earth’s atmosphere free from pollutants.
Ans: C
11. Study the photograph below. How does this photograph show a
consequence of ozone depletion on people?
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6. Earth: Our Home 2 (S/E and N(A))
QUESTION BANK Chapter 10
Source: Singapore National Eye Centre
A People may have weakened immunity through exposure to
ultraviolet radiation.
B People may develop cataracts through exposure to ultraviolet
radiation.
C People may develop cataracts due to rises in temperature.
D People may develop eye diseases such as typhoid due to rises
in temperature.
Ans: B
12. How does the Montreal Protocol help to reduce ozone depletion?
A The Montreal Protocol sets out to stop the use of greenhouse
gases.
B The Montreal Protocol sets out to stop the emissions of toxic
gases.
C The Montreal Protocol sets out to reduce the production of
greenhouse gases.
D The Montreal Protocol sets out to reduce the use and
production of CFCs.
Ans: D
13. Why are hybrid cars an alternative to other types of vehicles?
A Hybrid cars use solar-powered engines and water to run more
efficiently.
B Hybrid cars use diesel-powered engines to run more efficiently.
C Hybrid cars use both petrol and electric batteries to run more
efficiently.
D Hybrid cars use high quality petroleum to run more efficiently.
Ans: C
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7. Earth: Our Home 2 (S/E and N(A))
QUESTION BANK Chapter 10
14. Study the label below. How does this help people to be responsible
consumers?
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Courtesy of National Environment Agency
A It allows people to choose energy-efficient products.
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8. Earth: Our Home 2 (S/E and N(A))
QUESTION BANK Chapter 10
B It allows people to save electricity.
C It allows people to reduce the cost of the products.
D It allows people to differentiate one product from another.
Ans: A
15. How can we reduce the impact of global warming?
A By putting CFCs into old refrigerators and air-conditioners
B By buying products that are non-CFC-free to reduce emissions
of harmful gases
C By using more electricity at a time to reduce the amount of fossil
fuels being burnt
D By taking public transport to our destinations instead of private
vehicles
Ans: D
Structured Essay Question (15 marks)
1. Study the cartoon below carefully.
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9. Earth: Our Home 2 (S/E and N(A))
QUESTION BANK Chapter 10
(a) What is the environmental problem that is presented in this cartoon?
[2]
- The problem that is portrayed in this cartoon is global warming.
- Global warming refers to the increase in air temperatures
throughout the world.
(b) Explain the causes of this problem. [4]
- Global warming is caused by the emissions of greenhouse
gases.
- Due to increased human activities, more greenhouse gases such
as carbon dioxide, CFCs, nitrous oxide and methane are
released into the atmosphere.
- These gases trap heat in the Earth’s atmosphere.
- This results in the increased warming of the Earth’s surface and
lower atmosphere.
(c) Describe the consequences of this problem as shown in the cartoon.
[2]
- The melting of the ice caps at the North Pole causes the sea
levels to rise.
- This results in flooding.
(d) Why do you think the cartoonist portrays the consequences of this
problem taking place at the North Pole? [4]
- The extent of global warming is greater at the Poles.
- The North Pole experiences a higher rate of increase in
temperature.
- This is because when ice and snow in this region melt, the
ground has less white surface to reflect sunlight.
- More sunlight is now absorbed by the dark-coloured ground as
well as by the ocean.
(e) What can be done to reduce the impact of this problem? [3]
- Countries can accede to the Kyoto Protocol and agree to reduce
the emissions of greenhouse gases.
- Governments can use alternative sources of energy such as
solar and hydro-electric energy instead of fossil fuels.
- Individuals can buy energy-efficient products to reduce the use
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10. Earth: Our Home 2 (S/E and N(A))
QUESTION BANK Chapter 10
of electricity.
(Also accept other plausible answers.)
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