Global warming is caused by the increasing concentration of greenhouse gases like carbon dioxide and methane in the atmosphere from human activities such as the burning of fossil fuels and deforestation. This has led to a rise in average global temperatures of 0.6°C per century since the late 19th century and more extreme temperature highs and lows. Consequences include rising sea levels that threaten coastal regions, decreased food production in some areas, and increased health risks. Governments are implementing policies to limit pollutants and encourage renewable energy to control the problem.

1. GLOBAL
WARMING

2. Global Warming
• an average increase in the
temperature of the
atmosphere near the Earth’s
surface and in the
troposphere1, which can
contribute to changes in
global climate patterns

3. Causes
• Burning of fossil fuels (Coal/Crude oil)
– Power plants generate electricity
– Transportation-----fuels for transports (E.g. LPG,
kerosene, fuel oil)
– Industrial processes (E.g. manufacture of
cement, steel, aluminium)

4. Causes
• Other greenhouse
gases emission
– Agriculture
– Forestry
– Other land uses
– Waste management

5. Example : Using natural gas to cook
CH4 + 2O2  CO2 + 2H2O

6. Greenhouse gases in the atmosphere
↓
Some infrared radiation is trapped
↓
Greenhouse effect
Serious greenhouse effect
Global Warming

7. How serious the problem
is?...

8. Increase in greenhouse
gases
• Concentration of greenhouse gases in
the atmosphere is highly increasing by
human activities
→ Leads to the increasing seriousness of global
warming

10. Global surface
temperatures
– increased about 0.6°C/century since the
late19th century
– increased to 2°C/century over the past
25 years

11. Increase in Global
temperatures

12. Temperature difference
between different parts
of atmosphere
• troposphere temperatures (the lowest 8
kilometers of the Earth's atmosphere)
collected since 1979 also indicate warming
• Cooling effect in higher parts of the
atmosphere: stratospheric temperatures
have been decreasing

15. Increasing temperature
extremes
• Regions that have temperatures (1-3°C)
warmer than the average:
– United States
– Most of the Europe
• Regions that have temperatures (1-3°C)
cooler than the average:
– Australia

16. Sea level rising
• rising at an average rate of 1 - 2
mm/year over the past 100 years

17. Environmental
and Human
Effects

19. Air Quality
An increase in the concentration of
ground-level ozone
Damage lung tissue
Harmful for those with asthma and
other chronic lung diseases

20. Food supply
Rising temperatures and variable
precipitation
Decrease the production of staple foods in
many of the poorest regions
Increasing risks of malnutrition

21. Population displacement
Rising sea levels
Increase the risk of coastal flooding
(Necessitate population displacement)
• More than half of the world's population now lives
within 60km of the sea.
• Most vulnerable regions: Nile delta in Egypt, the Ganges-
Brahmaputra delta in Bangladesh, many small islands,
such as the Maldives, the Marshall Islands and Tuvalu.

22. Measures on controlling the
problem
• Government
* set some laws to limit the amount of
pollutants produced by factories
* develop the skills of using
renewable fuels, e.g. solar energy,
wind energy

23. Measures on controlling
the problem
* encourage the factories to replace fossil
fuels by renewable fuels, which would not
cause environmental pollution
* carry out energy saving scheme → reduce
the pollution produced by burning fossil fuels
* build more plants → reduce the pollutants e.g.
CO2