2. Essential Questions Definitions Learning outcomes
A. How has global
climate changed in
the last 150 years?
B. Is climate change
natural or human
induced?
C. What is greenhouse
effect and how does
it work?
D. What is the
enhanced
greenhouse effect?
E. How do human
activities lead to
climate change?
- Climate has
changed in the
past through
entirely natural
causes.
- Human activities
are impacting
the climate
system through
increasing the
amount of
greenhouse
gases in the
atmosphere
- Explain natural
causes
contributing to
climate change
- Explain the
greenhouse effect
- Explain how
various human
activities have led
to an increase in
greenhouse gases
which contribute
to the enhanced
greenhouse effect.
6. Sun emits differing amounts of solar
radiation due to changes in magnetic
field
High temperatures
Because more sunspots found
Sunspots = Higher solar activity
Low temperatures
Lesser sunspots found
Lower solar activity
* natural
7. * natural
Large amount of CO2, water vapour, sulphur
dioxide, dust and ash released
Results in global dimming
Gradual reduction of amount of sunlight reaching
the earth’s surface
Eg Mt Pinatubo in 1991
Lowers temperatures for 2 years
Temporary effects on earth’s climate
http://www.youtube.com/watch?v=2QENyRWdImY
9. •Glass panels lets in light but keeps heat from escaping.
•So plants can grow with the trapped heat from the sun.
*Greenhouse (Cold countries)
10. Greenhouse effect Enhanced greenhouse
effect
Definition
Natural process to trap
heat
Human activities
- Rapid increase in amount
of greenhouse gases
Effects
Positive
- Warm the earth’s
surface
Negative
- Rise in global
temperatures
Illustration
11. 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
12. •Greenhouse gases in atmosphere = Glass panel
•Traps heat naturally to keep Earth warm and livable
13. Yellow layer = Extra Greenhouse Gases / Air pollutants
*
Greenhouse
Effect
15. *Fossil fuels = oil, coal and natural gas
*Burning fossil fuels produces large amount
of energy
*Energy to be used for: Industries,
transportation, domestic and commercial
activities eg Electricity
*Contributes to carbon dioxide (results in
ENHANCED greenhouse effect)
16. *Loss of forests due to removal or clearance
of trees
*Reasons: Paper, building materials, mining,
animal grazing, planting crops,
infrastructure
*Results in lesser trees to absorb Carbon
dioxide in the atmosphere
20. *
1.Explain natural causes contributing to
climate change. [2]
2.Explain the enhanced greenhouse
effect. [3]
3.Explain how various human activities
have led to an increase in greenhouse
gases which contribute to the
enhanced greenhouse effect.[3]