Weather and climate updated

1. VARIABLE WEATHER AND
CHANGING CLIMATE
A Continuing Challenge?
1

2. Diagnostic Test
• To gauge your understanding of the
topic on weather and climate
• Circle your answers
• 5 – 10 mins
• Page 96
2

3. Diagnostic Test Answers
3

4. What is the difference between
weather and climate?
Weather:
Condition of atmosphere at a particular place
and specific time.
Climate:
Average condition of the atmosphere of a
particular place over a long period of time,
usually 30 years.
4

5. Question
• Define the terms ‘ weather’ and ‘climate’
• Page 24
5

6. Weather elements
- Definition
- Instruments
1)Temperature - calculations
2)Rainfall / precipitation
3)Relative Humidity
4)Wind / Breeze - Diagram
5)Cloud cover
6

7. TEMPERATURE
Definition:
Degree of hotness or coldness of a place.
7

8. Temperature
• Temperature is measured using an
analogue or digital thermometer.
• Temperature is read on a maximum
and minimum thermometer (Sixes
thermometer) by observing the
lowest point of each metal index
(blue line). For example, in the figure,
the minimum temperature is 20°C
and the maximum temperature is
25°C.
• The diurnal temperature range is
therefore 5°C.
A digital thermometer
A maximum and minimum thermometer
http://www.youtube.com/watch?v=1JSL4bdd_8
4 to learn to read a minimum and maximum
thermometer.

9. P10 Describe the advantages of using a digital
thermometer and a hygrometer over a maximum-
minimum thermometer and a wet and dry bulb
thermometer. [4]
9
 The digital thermometer and hygrometer can
give instant readings. Thus, one does not have to
work out the answer.
 Easy / clear to read with a large digital readout
 One does not need to learn how to read a
thermometer.
 Parallax errors can be avoided since one does
not have to read off thermometer.
 Since exact figures are given, the measurements
are more accurate.
 Portable / can be used at more than one site
 Safer to use as there is no mercury content

10. • Different locations have different
temperatures due to different LATITUDES
• But places along the SAME latitude can also
have different temperature because of
- Altitude
- Distance from the sea
- Cloud cover
Little Ahmad Dislike Class 10
TEMPERATURE

11. LATITUDE
Imaginary horizontal lines east to west of Equator.
The nearer the
Equator, the
higher the
temperatures.
The further
from the
Equator, the
lower the
temperatures.

12. ALTITUDE
Definition:
• Height of a place in relation to sea level
- General decrease of 6.5°C for every 1,000 m increase in altitude.
12

13. How does altitude affect temperature?
• Distance from surface of the earth
- Longwave radiation is heat emitted by the earth
after absorbing shortwave radiation
- Most heat absorbed by the earth at lower
altitudes -> little heat at high altitudes -> cooler
• Density of air
- Air is less dense at higher altitudes -> absorb less
long wave radiation -> lower temperatures
13

14. DISTANCE FROM SEA
LOCATION LATITUDE DISTANCE
FROM SEA
TEMPERATURE
RANGE
ANCHORAGE 61.1919° N 1 KM 20°C
FAIRBANKS 64.8378° N 420KM 40°C
• The sea heats and cools more slowly than
land
• This influences the temperatures of inland
and coastal areas.
14

15. Maritime Effect:
Effect large ocean bodies have on
climate of coastal areas.
• Small temperature range
• Cool summers and warm winters
Continental Effect:
Effect huge land surfaces have
on climate of inland areas.
• Large temperature range
• Hot summers and cold winters
15
DISTANCE FROM SEA

16. P24
16

17. With cloud cover Without cloud cover
Day: Cooler
-> Clouds reflect sun’s energy back to
space.
Night: Warmer
-> Clouds prevent heat radiated from
ground from escaping.
Day: Warmer
-> Large amount of sun’s energy reaches
earth’s surface.
Night: Cooler
-> Allows more heat radiated from ground
to escape. 17
CLOUD COVER

18. P25
• Latitude
• same latitude = same angle
of incidence from the sun’s
rays
• same amount of
concentration of sunlight
from the sun
• E.g. SG and Malaysia :
similar temp 18
‘Areas along the same latitude experience similar
temperatures.’ How far do you agree with the statement?
Support your answer using evidence.

19. Different temperature due to:
Altitude
• Vertical distance from the sea level
• Higher altitude = lower temp because
• Earth’s surface is heated by sun’s rays
• Heat emit into atmosphere via longwave radiation
• Higher altitude = further away from earth’s surface = less longwave radiation absorbed = less heat = lower temp
than lower altitude
• In addition, Higher altitude – air is less dense: absorb less heat
E.g. Cameron Highlands is higher altitude, lower temp than Kuala Lampur in Msia/ Mt Batur in Bali is higher altitude,
lower temp than Kuta in Bali
Distance from the sea
• Sea heats up and cools down slower than land
• Coastal areas: maritime effect – air over sea is warmer than inland during. Therefore, warmer winter and air
over sea is cooler than inland during summer. Therefore, cooler summer
• Inland: continental effect – warmer summer and cooler winter
E.g. Anchorage is coastal area, Fairbanks is inland .Anchorage experience maritime effect and would not have same
temperature as Fairbanks even though they are of the same latitude.
Conclusion:
• Areas of the same latitude might have similar temperature but may not be true for all regions as there are other
factors that affect temperature, such as altitude and distance from the sea. 19

20. Homework P97
20

21. Homework P97 Identify the 6
characteristics of a Stevenson’s screen
21

22. RELATIVE HUMIDITY
• The amount of water vapour in the air that can
hold at a given temperature
High RH , Eg Singapore Low RH, Eg Sahara Desert

23. 23
What will happen when RH is at 100%?
• Clouds will
be formed
when dew
point
temperature
is reached.

24. What happens to Relative humidity
if we change the temperature?
• Air
molecules?
• Water vapour
molecules?
24

25. RELATIVE HUMIDITY
- At higher temperatures, the air will be able to
hold more water vapour as air molecules are
more spread out ( ), more water vapour ( )
can fill the spaces.
25Higher temperatures - RH 70% Lower temperatures – RH 20%

26. P26
26

27. 27

28. Relative humidity
Sling psychrometer
1. Dip the wick of the wet bulb in
water and swing the
psychrometer for 1 min.
2. Record the reading. Repeat step
1 until both readings are
consistent.
3. Read the temperature off the
dry bulb.
4. Obtain the depression of the
wet bulb, take the DRY – WET
reading
5. Using the table, obtain the
relative humidity by finding the
value where the wet bulb
depression intersects with the
dry bulb temperature.

29. P10
29

30. P27
With reference to Fig. 1, identify the
instrument used by the students and state
the relative humidity recorded for that day.
Explain how the students obtain this
information, using evidence from Fig.1.
[5]
 Instrument used: wet and dry bulb
thermometer (compulsory)
 Relative humidity recorded: 61%
(compulsory)
 Read/record the dry bulb temperature,
which is 33° C
 Read/record the wet bulb temperature,
which is 27° C
 Find the wet bulb depression is 6° C
[5 @ 1 mark]
30

31. P9 – hypothesis , temperature, relative
humidity
31

32. P9
32

33. Class activity P98
• Get into groups
• 3 instruments : A, B and C
• Venue X : Parade Square
• Venue Y : Canteen
• Venue Z : Foyer
33

34. • Rainfall: Water that falls from the
atmosphere to the surface of the earth.
• Two main kinds of rainfall we will learn
about:
- Convectional rainfall
- Relief rainfall
34
RAINFALL / PRECIPITATION

35. Convectional rain
• Most common rainfall type in the tropics.
- Linked to lightning and thunder.
- Short but intense periods of rain.
• Formation
Sun’s rays heat up earth’s surface
Air expands and rises
Temperature drops at high altitudes and air cools to dew point
Condensation occurs and clouds are formed
Rain falls
35
http://www.curriculumbits.com/prodimages/details/geography/types-of-rainfall.html

36. Convectional rain
36

37. Relief rain (Orographic-mountain)
• Relief rain: Occurs when warm, moist air is forced to rise
over landforms such as a mountain range.
37

38. Hawaii Pali Lookout – Windward Side
( Strong Winds, Very cloudy, High
rainfall)
38

39. P26
4 With the aid of a well-labelled diagram, account for the
formation of relief rain. [5]
1. As the wind blows across the sea, it picks up moisture.
2. When the moist air encounters the highland, it is
forced to rise.
3. As the air rises, temperature decreases and relative
humidity increases.
4. At dew point temperature, the air is saturated and
condensation soon occurs where water vapour
condense to water droplets to form clouds.
5. When the water droplets are too heavy to be
suspended, they fall as relief rain on the windward
side of the highland.
39

40. Precipitation
The amount of precipitation is
measured in millimetres using a
rain gauge. A simple rain gauge can
be made using a funnel and a jar or
tin. To determine the amount of
precipitation:
1. Find an appropriate spot to
place your rain gauge and
position the rain gauge in an
open area.
2. Place the rain gauge into the
ground with about 30 cm
protruding above ground.
3. Record the time at which the
rainfall events start and end.
4. Pour the collected water in the
rain gauge into a measuring
cylinder. Read and record the
water level.
http://www.youtube.com/watch?v=pF5de4eKzO0

41. Homework P99
(i) Instrument used to measure rainfall is RAINGAUGE
(ii) Describe how they should place the rain gauge
1. Find an appropriate spot to place your rain gauge and
position the rain gauge in an open area.
2. Place the rain gauge into the ground with about 30 cm
protruding above ground.
3. Record the time at which the rainfall events start and
end.
4. Pour the collected water in the rain gauge into a
measuring cylinder. Read and record the water level.
41

42. Air Pressure
• Force exerted on a unit area of the
earth’s surface by the weight of a column
of air above it.
- Measured in millibars (mb) using a
barometer
- Air pressure decreases as altitude increases
Air is less dense hence the weight of the
column of air at higher altitudes is lower.
42

43. Air pressure
• Air pressure is measured in
millibars (mb) using a barometer.
• A barometer has two needles.
Check that the moveable pointer
is arranged over the measuring
hand to mark the current
pressure.
• The pressure is falling if the
measuring hand moves to the
left, and rising if the measuring
hand moves to the right.

44. Wind
• Moving air created when neighboring locations
have different air pressures.
- Air moves from high to low pressure.
- The larger the difference in pressure, the faster the
wind speed.
• Two kinds of wind systems we will learn about:
- Land and sea breezes
- Monsoons
44
http://www.classzone.com/books/earth_science/terc/content/visualizations/es1903/es1903p
age01.cfm?chapter_no=visualization

45. Sea breeze
• Sea breeze: Wind that blows from sea to land
45

46. Sea Breeze
• Sea breeze occurs during the day
Land absorbs heat faster than water
Higher temperatures over land than sea
Pressure is lower over land than sea
Wind blows from high pressure area over the sea to low pressure
area over the land
46

47. Land breeze
• Land breeze: Wind that blows from land to sea
47

48. Land Breeze
• Land breeze occurs during the night
Land loses heat faster than water
Higher temperatures over sea than land
Pressure is lower over sea than land
Wind blows from high pressure area over the land to low
pressure area over the sea
48

49. P27
49

50. Nearpod
50

51. Wind speed and direction
Anemometer
• Hold up the anemometer in an
open area where there’s no
obstruction
• The cups will rotate faster with
more wind
• Read the wind speed indicated.
Issue :
- Human error when reading the
measurements
- Enclosed area without wind
Anemometer

52. Wind speed and direction
Wind vane
Wind vane
• Place the wind vane at where the wind is blowing.
• The direction the wind vane points to is the direction where the wind is blowing
from.
Issue :
- Determine where the North is using a compass
- Error in reading the directions

53. Wind speed and direction
Wind rose
Wind rose
• Rectangle numbers =
DATES that wind is
blowing in that direction
• Circle number = DATE that
there’s no wind
Issue :
- To identify which
direction has prevailing
wind in that month
- Must know how to draw!

54. P12
54

55. P11 – Hypothesis, limitations,
conclusions
55

56. P11
56

57. 5
Homework P99
• Identify the instrument used : Wind vane
• Construct a suitable mode of presentation to
present the information shown in Table 1.
57
2

58. 58
Monsoon winds

59. Monsoon winds
• Regional wind pattern that reverses direction
seasonally. This will result in seasonal changes
in precipitation.
• Monsoon winds affected by the Coriolis effect.
- Coriolis effect is a force produced by the earth’s
rotation
- Earth’s rotation will deflect the wind’s direction.
59
http://www.classzone.com/books/earth_science/terc/content/visualizations/es1904/es1904page01.cfm?chapter_no=visualization

60. Monsoon wind — Coriolis Effect
60

61. 61
Singapore
- Experience NE monsoon wind at the end of the year (Heavy rain)
- Experience SW monsoon wind in the middle of the year (Light rain)

62. India
(light rain)
62
Oct to Feb
Equator
(Coriolis effect
-Deflect left)
Australia
(heavy rain)
China
Spore
(heavy rain)
High
pressure
(Winter)
Low
pressure
(Summer)
Northeast
monsoon
Northwest
monsoon
INDIAN
OCEAN

63. Explain the formation of the monsoon
wind identified in (i).
• Area of low pressure forms over Australia during
summer
• India is experiencing winter, on the other hand,
forming area of high pressure
• Air moves from India to Australia due to the
difference in pressure
• Coriolis effect deflects the winds to the left when
they cross equator, forming the North-East
monsoon 63

64. Northeast - Northwest monsoon
• Months = October and February.
– North hemisphere : Higher pressure (Winter)
– South hemisphere: Lower pressure (Summer)
• Direction of wind
– generate NE winds from North to South as wind
blows from high to low pressure
– As the winds cross the Equator, they change direction
to NW due to Coriolis effect.
64

65. Northeast - Northwest monsoon
65
NE-NW
monsoon
blows across
the Indian
Ocean,
carrying lots of
moisture,
bringing heavy
rain to
Australia

66. Explain why Delhi receives very light
rainfall in Fig. 4. [4]
66
Fig. 4
Partner
work

67. Explain why Delhi receives very light rainfall
in Fig. 4. [4]
• Delhi receives light rainfall due to northeast
monsoon (October – February)
• an area of high pressure forms overs Indian sub-
continent and Central Asia while an area of low
pressure forms over Australia
• due to differences in pressure between the northern
and southern hemispheres, air moves from Central
Asia down towards Indian sub-continent
• resulting in drier and colder winds that bring with it
light rainfall as they blow across cold land to Delhi
67

68. India
(heavy rain)
68
June to Sep
Equator
(Coriolis effect,
deflect right)
Australia
(light rain)
China
Spore
(light rain)
High
pressure
(Winter)
Low
pressure
(Summer)
Southwest
monsoon
Southeast
monsoon
INDIAN
OCEAN

69. Southwest -Southeast monsoon
69
• Months = June to September
– North hemisphere : Lower pressure (Summer)
– South hemisphere: Higher pressure (Winter)
• Direction of wind
– generate SE winds from South to North as wind blows
from high to low pressure
– As the winds cross the Equator, they change direction
to SW due to Coriolis effect.

70. Southeast - Southwest monsoon
70
SE - SW
monsoon
blows across
the Indian
Ocean,
carrying lots of
moisture,
bringing heavy
rain to Indian
sub-continent

71. With reference to Fig. 6, explain how
Mangalore, India is affected by Southwest
monsoon. [4
Partner
work
P29
Fig. 6

72. • Max 3 marks awarded only if student never make reference to
Mangalore, India.
• Between June and September, when it is summer in the northern
hemisphere. Air over Central Asia heats up, expands and rises,
forming a region of low pressure over the area.
• During the same period, the southern hemisphere is experiencing
winter. The low temperature causes the air to be cold and dense,
exerting a greater force on the earth’s surface. This results in an
area of high pressure over Australia.
• Due to the difference in pressure between Central Asia and
Australia, air from Australia moves to the Indian sub-continent
and Central Asia as the southeast monsoon winds. As the winds
cross the Equator, the Coriolis effect deflects the winds to the
right.
• These winds become the southwest monsoon winds and warm
up as they head for Central Asia. The warm air picks up moisture
as it travels over the Indian Ocean and brings heavy rain to the
Mangalore, India.
72

73. Using your understanding of the topic, identify the
monsoon wind shown in Fig. 7 and explain its
formation. [4]
73
 It is the SouthWest Monsoon [1m]
 In June to Sept, the southern hemisphere is having winter
and the Northern hemisphere is having summer [1m]
 The wind moves from Southern Hemisphere which is of
higher pressure towards the Northern Hemisphere which
is of a lower pressure[1m]
 Due to the Coriolis effect, the winds are deflected to the
right in the Northern Hemisphere, which results in the
Southwest monsoon winds blowing across India [1m]

74. We will learn about 3 key climate types:
1) Equatorial Climate
2) Monsoon Climate
3) Cool temperate (marine west coast)
74

75. Types of Climate
75

76. Equatorial Climate
76
How would you describe the temperature and rainfall of this climate?

77. Equatorial climate
77
• High temperatures, high rainfall, high
humidity all year round.
• Dominantly convectional rain with large
cloud cover: small diurnal range
• Places are located between 10° north and
south of Equator.
- Examples: Singapore, Malaysia, Congo, Brazil

78. Monsoon Climate
78
How would you describe the temperature and rainfall of this climate?

79. Monsoon climate
• High temperatures, high rainfall, high
humidity all year round.
• Distinct wet and dry season
• Moderate temperature range (7.5° C)
• Located between 5° and 25° north and
south of Equator
- Examples: India, Sri Lanka, Vietnam
79

80. Cool temperate Climate
80
How would you describe the temperature and rainfall of this climate?

81. Cool temperate (marine west coast)
climate
• Mild winters and cool summers
• Rainfall evenly distributed but total
annual rainfall is lower than in places
with equatorial and monsoon climates.
• Large temperate range of 25°C
• Located between 45° and 60° north and
south of Equator.
- Examples: France and Canada
81

82. Climographs
1. Mean monthly
temperature -
line graph
2. Total monthly
precipitation –
bar graph

83. Describing climographs
1. The months where the
minimum and maximum
temperatures are
experienced.
2. The average
temperature range
3. The months where it
minimum and maximum
rainfall are experienced.
4. The total amount of
rainfall experienced in
the place

84. Equatorial climate
84
Describe the climograph in terms of :
• Temperature range Small: 1.6⁰C
• Rainfall pattern Relatively high rainfall every month
• Rainfall and temperature values High amount of rainfall of more than
2,000mm a year, high annual temperatures of around 26.5-28.1⁰C

85. Monsoon climate
85
• Temperature range Moderate: 6⁰C
• Rainfall patterm Distinct wet (May- Sep) and dry (Oct-Apr) seasons
• Rainfall and temperature values High amount of rainfall of more than 2,000mm a year, high
annual temperatures of around 22.2-27.8⁰C

86. Cool temperate (marine west-coast)
climate
86

87. Singapore’s Climograph
87
Using Fig.1,
describe the
climograph of
Singapore. [4]
Fig. 1

88. Nearpod
88

89. P28
89

90. P28
90

91. P30
91

92. P30
92

93. How has global climate changed?
• Global Climate Change: variation in the global
climate or climatic patterns in the long term.
How has
temperatures
changed from
1800 until 2000?
93
Trend: General increase over the years; sharp
increase in temperatures between 1980-2000

94. GLOBAL TEMPERATURE INCREASE
• Changes in global climate since 1881.
- Earth warmed up by 0.74° C in 100 years.
- Greatest increase after 1980s
- Some places recorded much higher temperature
increases.
 Arctic, Asia and Africa (1.2° C to 1.4 ° C)
94
Video: http://www.youtube.com/watch?v=2_ZQRIsn2pA
Q: What are the impacts of a one degree change?

95. Do you think 1 degree Celsius
can affect the world? How?

96. P31
96

97. P31
97

98. GH effect
A natural phenomenon where gases
in Earth’s atmosphere trap heat
from the sun to warm the surface
and lower atmosphere
Enhanced GH effect
Accelerated GH effect due to rapid
increase in GH gases in the
atmosphere, trapping more heat
from the sun

99. .Relationship of Earth &
Atmosphere
Relationship of Body &
Clothes
The atmosphere is the
layer of air around the
earth to keep it warm.
Allows the right amount
of sun’s heat in, and
doesn’t allow too much to
escape.
The clothes are the
layer around our body
to keep us warm
Allows the body to
maintain a certain
temperature.

100. Warming of the Earth Warming of the Body
We are warmed by
1. Body gives out heat
2. Heat from the sun
3.Trapped heat from
the clothes
Earth is warmed by :
1. Itself – gives out heat
2. Heat from sun
3. Trapped heat from
Greenhouse effect
A natural Greenhouse effect
allows the sun’s rays to
enter earth and keep the
heat inside
Necessary to keep Earth
warm and livable.

101. ENHANCED
Greenhouse effect
Extra Warming of
the Body
• When you put on a
jacket unnecessarily
• More heat being
trapped
• Result = Warmer
body
When there’s MORE
greenhouse gases in
atmosphere
unnecessarily
Due to industrialization
More heat being
trapped
Result = Global
Warming (hotter earth)

102. Heat
that
reaches
earth
Heat that are
reflected back
by earth &
atmosphere
Heat is
trapped
by GH
gases
Heat
given out
from the
earth
Greenhouse
gases in the
atmosphere
Solar radiation from the Sun to Earth

103. What is a greenhouse?
103

104. •Glass panels lets in light but keeps heat from escaping.
•So plants can grow with the trapped heat from the sun.
Greenhouse
(Cold countries)

105. •Greenhouse gases in atmosphere = Glass panel
•Traps heat naturally to keep Earth warm and livable

106. Yellow layer = Extra Greenhouse Gases / Air pollutants
Enhanced
Greenhouse
Effect

107. •What are
greenhouse
gases?
107

108. Greenhouse
Gases
Carbon dioxide
Causes of Greenhouse effect
Source •Respiration
•Burning of fossil fuels
& forests
What is the % in
the atmosphere?
Newspaper article on Carbon reduction and
alternative sources of energy
72% (Highest percentage
of greenhouse gas)

109. Greenhouse
Gases
Chlorofluorocarbons
(CFC)
Causes of Greenhouse effect
Source •Aerosol spray cans
•Coolant in refrigerators
and air-conditioners
What is the % in the atmosphere?
13%

110. Greenhouse
Gases
Methane
Causes of Greenhouse effect
Source •Decomposition of waste
•Livestock eg cattles/goats
belch
•Mud, volcanoes
What is the % in the
atmosphere? 10%

111. Greenhouse
Gases
Nitrous Oxide
Causes of Greenhouse effect
Source •Burning of fuel
•Chemical fertilisers
(Which topic did we
learn about this?)
Proportion in
atmosphere
5%

112. Greenhouse effect
• Greenhouse effect:
– Natural process
– Gases in the Earth’s atmosphere traps heat
– Warms the atmosphere.
• Greenhouse gases
– Water vapour, carbon dioxide, methane, nitrous oxide
ozone and halocarbons such as chlorofluorocarbons
(CFCs)
– Absorbs heat
112

113. 113

114. Enhanced greenhouse effect
• Increase in the concentration of
greenhouse gases
• Causes a rise in global temperatures.
• Due to human activities
• Increased amount of greenhouse gases
eg carbon dioxide.
114

115. 115

116. Natural causes
• Variations in solar
output
• Volcanic eruptions
Anthropogenic causes
• Burning of fossil fuel
• Deforestation
• Changing land use
– Agriculture
– Industrialization
– Urbanization
116
Causes of climate change?
Because Darren Can Always
Iron Uniform

117. • Describe how variation in solar output
affects the global climate change? [3]
- Point
- Elaborate
- Example
Use textbook only to assist you.
117

118. Variations in solar output
• The magnetic activity of the
sun has a cycle that lasts
about 11 years.
• An increase in solar radiation
is due to an increase in sun
spots.
– Areas surrounding the
sunspots radiate more
energy to make up for the
cooler sunspot areas.
• With higher solar radiation,
earth’s temperatures will
increase.
Sunspots represented by the dark spots
on surface of the sun.
118

119. Example
In 2000, the number of
sunspots observations
reach up to 170, which
coincided with high
solar activities.
When the solar activity
reached its minimum,
global temperatures
then were also lower
than those in the past
20 years.
119

120. Volcanic eruptions
• Global dimming: Gradual reduction in the amount of
sunlight reaching the earth’s surface. Temporarily cools
the earth for months or years.
– Dust particles from eruption form condensation nuclei,
creating more cloud cover.
– Dust and ash also reflect away incoming solar radiation.
• For example, Mount Pinatubo eruption lowered
temperatures by as much as 0.6°C for as long as two
years.
120
Q: How volcanic eruptions can lower global temperatures?
http://www.youtube.com/watch?v=aQRvJHtfP1o

121. How do human activities lead to enhanced
greenhouse effect?
• Burning fossil fuels
• Deforestation
• Changing land use
– Agriculture
– Industries
– Urbanisation
121
Proportion of greenhouse
gases in atmosphere
Carbon
Dioxide
(72%)
Methane
(10%)
Nitrous
Oxide (5%)
CFCs (13%)

122. Deforestation
• Loss of forests due to the removal or
clearance of trees in forested areas.
• Causes increase in levels of carbon dioxide in
three ways:
–Fewer trees to absorb carbon dioxide
–Carbon oxidation: When soil is exposed to
sunlight, the carbon in soil reacts with oxygen to
produce carbon dioxide, this is aided by higher
temperatures
–Burning of trees produces Carbon dioxide 122

123. Burning fossil fuels
• Fossil fuels: formed from decomposition
of dead organic matter over millions of
years
- For example, petroleum, coal and natural
gas.
- Powers 80% of the world’s energy
- Contains high carbon content, releases huge
amount of carbon dioxide when burnt
- Highest contributor of greenhouse gases.
123

124. Burning fossil fuels
124
Describe the trend of burning fossil fuel using Figure 1. [3]
• All three fossil fuel increased from 1950 till 2005.
• Oil has the biggest increase and the highest usage (3,800 tonnes).
• The usage of coal is increasing at a slower rate compared to oil and
natural gas.

125. Changing land use
125
Agriculture Industries Urbanisation
Farming practices
eg grow of crops
or rear of animals
Manufacturing
of goods by
machines and
mass production
Development into
a city eg buildings
and high
technology

126. Agriculture
Practice of cultivating land, producing crops and
raising livestock.
Name the three key gases released during crop cultivation.[3]
Carbon Dioxide, Nitrous Oxide, Methane

127. Agriculture
• Cattle farming releases millions of tonnes of
methane into the atmosphere annually, as gases are
released from the digestive systems of cattle.
127
Greenhouse gas emissions
from agriculture and land use

128. Industries
• Production of
goods and services
within a country.
–burning of fossil
fuels to create
energy needed
to run factory
processes. 128

129. Urbanisation
• Process by which an increasing number of people
live in urban areas.
129
- Human activities leads to
increased in Greenhouse
gases
Examples
- Burning of petrol in cars
for energy
- Burning of fossil fuel to
generate lights

130. P33, P34, P35
• ‘Deforestation is the main cause of global
warming.’ How far do you agree with this
statement? Support your answer using evidence.
[6]
• Using specific examples, explain two
anthropogenic factors that led to enhanced
greenhouse effect. [6]
• Assess the international agreements that have
been implemented to address global warming. [6]
• Assess the national effects that have been
implemented to address global warming. [6]
130

131. Impact of climate change
1) Sea level rise
2) Frequent extreme weather events
3) Spread of infectious insect-borne
diseases
4) Lengthening of growing season in
certain regions
131
Sharifah Eats Dried Grapes
Video: http://www.youtube.com/watch?v=btp01Az0ZcU (Climate change and extreme weather)

132. Sea level rise
• Increase in the mean height of the sea’s
surface between high and low tide
relative to land.
–Higher temperatures causes water to
expand
–Higher temperatures causes glaciers to
melt, adding meltwater to the sea
132

133. Frequent extreme weather events
• Severe and rare weather
phenomenon
• Results in significant economic
losses and the loss of lives
- Eg. Heat waves, floods, droughts and
tropical cyclones
133
http://www.youtube.com/watch?v=btp01Az0ZcU
1)Why do extreme weather events occur?
2)What are the kind of destruction you can see from the
video?

134. Spread of infectious insect-borne diseases
• Link between insect-borne diseases and
climate change:
- Increased rainfall and temperatures is
favourable for mosquitoes to breed
- allows spread of malaria and dengue fever
- As temperate countries get warmer,
mosquitoes are able to breed further up
north of the Equator
- eg Dengue fever in Nepal
134

135. 135

136. Lengthening of growing season in
certain regions
• Higher temperatures have lead to longer growing
seasons for some regions.
- Advantage (Cold regions are now warmer, more
conducive for crop growing)
• Increase in types of crops that can be grown in UK.
• Increase in fruit, soybeans, potatoes and wheat in
Canada.
- Disadvantage (Cool regions are now getting hotter,
less conducive for crop growing)
• Apples and cherries production in Yunnan is reduced as they
need cool conditions.
• Wheat yield has decreased in Canada.
136

137. P32
‘ The spread of insect – borne diseases is the
most significant impact of enhanced greenhouse
effect’.
To what extent do you agree with this
statement?
Give reasons for your answers. [6]
137

138. What are the responses to climate
change?
• International Level
–Kyoto Protocol (1997)
• National Level
–Singapore
138

139. Kyoto Protocol
• Kyoto Protocol: An international
agreement to reduce greenhouse gases
emission into the atmosphere.
–Drawn up on 11/12/97, came into effect
16/02/05
–Different countries have different targets to
hit and progress of carbon emissions will be
tracked and reported for review.
139

140. Kyoto Protocol
Successes
• Many countries met or exceeded targets set
by Kyoto Protocol as there was constant
monitoring and reporting by countries for self
and peer assessment.
• Encouraged sustainable development.
- Developed countries are encouraged to work
with developing countries in carbon-reducing
projects (Clean Development Mechanism —
CDM) 140

141. Kyoto Protocol
Limitations
• Not all countries are able to meet their goals and
not all countries have the same emission targets.
- Denmark, Sweden and the United Kingdom did not
achieve their targets
• Many countries did not sign the Kyoto Protocol and
continue to contribute to global emissions.
- A large portion of the increase in global emissions came
from China, India and the United States of America
141

142. 142

143. National response: Singapore
1) Singapore Green Plan 2012
• Reduce energy consumption and greenhouse
emission from burning fossil fuels
2) Green Mark Scheme
• Constructing ‘green’ buildings
3) Plant-A-Tree programme
• Planting more trees and plants
143

144. Singapore Green Plan 2012
144

145. Singapore: Green Mark Scheme
145

146. Singapore: Plant-A-Tree programme
146

147. 147