A short description about global warming, It's causes, effects and it's control.

2. Index
Introduction
History
Green house gases
Global Warming Impacts
Control

3. Global Warming
An average increase in the
temperature of the
atmosphere near the Earth’s
surface and in the
troposphere, which can
contribute to changes in
global climate patterns

4. • Since the late 1800’s, the global average
temperature has increased about 0.7 to
1.4 degrees.
• The concentration of green house gases in
the atmosphere were artificially raised by
humans since past 250 years.

5. Green house effect:
How does it work
The greenhouse effect insulates
earth, resulting in the mild temperatures at
the earth's surface that have allowed life to
flourish.
The greenhouse effect is absolutely vital to
allowing life, as we know it to survive on
earth. Without the greenhouse effect, earth
would be a cold planet, with a mean surface
temperature well below freezing.

6. Main Warming Mechanism:
The Greenhouse Effect
Our earth receives most of its energy in the form
of radiation from the sun
The incoming solar energy (Ultra Violet UV) has
a very short wavelength and passes through the
atmospheric gases unaffected to reach the earth
surface
The earth surface absorbs the solar energy and
releases it back to the atmosphere at a different
wavelength as infrared (IR) radiation, some of
which goes back into space

7. Some of the IR radiation emitted by the earth
is absorbed by greenhouse gases in the
atmosphere.
These gases absorb the infrared radiation
emitted by the earth and re-radiate the
energy as heat back towards the earth
causing a warming known as the greenhouse
effect.

9. Present Day Climate Change:
In the history of earth, climate change
happened many times.
Ones more in the history of the
earth, the climate is changing.
There is however several differences
between past changes in the climate
and what we are observing today:

10.  - Present climate change is occurring very rapidly as
opposed to past climate changes which usually
occurs over millions of years (rapid change have
occurred in the past but has a result of catastrophic
events only e.g. meteorite impact, large volcanic
eruptions, sudden feedback)
 - Present day climate change is not a natural event
but a result of human activity
 - Present day climate change can be prevented as we
do know the causes and how to limit the impacts

11. Brief History Of The Earth Climate:
Natural Variability
 The Earth is a very dynamic planet which
has undergone many transformations
throughout its history and since its
formation 4.6 billion years ago.
A succession of geological events and the
appearance of life have dramatically
influenced the climate of the earth.

12. History
The field of Paleoclimatology has
provided information of climate change
in the ancient past, supplementing
modern observations of climate.
Climate variability usually occurs
naturally on the planet over millions of
years or suddenly as a result of a
catastrophic event (e.g. major volcanic
eruptions, meteor impacts).

13. Few Examples
Miocene Climate: (23–15 MYA)
 The climate during which was warmer than today's
climate.
Early Cretaceous Climate: (145-65 MYA)
The Early Cretaceous was a mild "Ice House" world.
Early & Middle Jurassic Climate: (206-144 MYA)
Deserts covered what is now the Amazon and Congo
rainforests.

14. History
Late Devonian Climate: (360 MYA)
Thick coals formed for the first time in the tropical
rainforests.
Early Permian Climate: (280 MYA)
Much of the Southern Hemisphere was covered by
ice as glaciers pushed northward.

15. Example Of A Warmer Climate:
Early & Middle Jurassic Climate
(206 To 144 Million Years Ago)
The Jurassic is an example of a climate era
which was much warmer than the climate
that we are experiencing today.
Much of the Jurassic world was warm and
moist, with a greenhouse climate.

16. Early & Middle Jurassic
Climate
The polar areas were ice-free during
this period.
The ocean surface stood at a higher
level with respect to the continents.
Much of the earth was covered in warm
and moist tropical forest

17. Example Of A Colder Climate: The
Ordovician Climate (488 To 444 Million
Years Ago)
The Ordovician is an example of a past climate
which was much colder than the climate that we
are experiencing today
Great Ice Age that gripped the earth at this
time.
There were even glaciers in what is now the
Sahara.
About 60% of animal genera became extinct,

18. Carbon dioxide (CO2)
Methane (CH4)
Nitrous oxide (N2O)
Chlorofluorocarbon (CFC)
Water vapour (H2O)

19. Carbon dioxide :
 It is generated by the human
activities like burning of
coal, wood, natural gas.oil
etc.
 It is also released by animals
& human beings during the
process of respiration.
 The trees take in the carbon
dioxide, therefore
deforestation is also an
important reason for increase
in carbon dioxide.
 It accounts for 50% of the
gases responsible for global
warming.

20. METHANE
 Methane accounts for
16% of all gases
responsible for global
warming .
 It is estimated that nearly
30 to 200 million tones of
methane is released
every year.
 The main source of
methane is rice field.

21. NITROUS OXIDE
 It is generated due to burning
of
biomass, agriculture, livestock
waste, nitrogen rich fuels.
 It accounts for 6% of the gases
responsible for global warming.

22. Chlorofluorocarbon [CFC]
 It accounts for nearly 20% of the gases
responsible for global warming.
 These are non-toxic, nonflammable & highly
stable compounds.
 They are also used as coolants in compressors of
air conditioners & refrigerators.
 They are also use in insulators, fire extinguishers,
aerosol etc.

23. Gas Major Source %
Contri
bution
Carbon dioxide Fossil fuel & deforestation 50
Methane Fossil fuel, wood burning. 16
Nitrogen Oxide Wood burning, fertilizer, fossil fuel. 06
Chlorofluro carbons & Industries, insulation, refrigeration. 20
other carbon

26. What’s the proof that
global warming is taking
place?

27. Portage Glacier
Alaska
1914 2004
Photos: NOAA Photo Collection and Gary Braasch – WorldViewOfGlobalWarming.org

28. Colorado River
Arizona
June 2002 Dec 2003

29. Ocean
Life
Living
Habitat
Plants
Impact of
rise in
CO2
Emission temperature Weather
of 1.8oC to
4oC
Crops Sea level
Human
Health

30. Effects of Global Warming
Rising Sea Level Increased Temperature
Habitat Damage and
Species Affected Changes in Water Supply

31. Effects Of
Global
Warming
Human Plants & Human Marine
Animals Agriculture
Society Beings Life

32. On human Society:
• Siberia & Canada might experience
increase in temperature from 10 to 12
degrees.
• The rainfall have increased by 2 to 3%
per decade over tropical regions due to
high rate of evaporation.

33. On Plants & Animals:
• Slowly disappearing & eventually die if
the current trend in global warming
countries.
• There are rapid rise in global temperature
in next 100 years
• The wetland & coral reef may also
undergo decline due to climatic changes

34. On Agriculture:
• There may be negative effect on various
type of crop in different regions of the
world.
• Soil moisture may decrease, water
requirement of the crop will increase &
will affect the crop yield.
• Due to Green house effect, several plants
cripple down their size, fruits & leaves.

35. On Human Health:
• It may lead to changes in rainfall
pattern & some areas may
become breeding ground for
mosquitoes & some other insects
which are vector of disease like
malaria, dengue fever, yellow
fever, etc.
• In low rainfall there will be
waterborne disease.
• Heat waves are harmful to
health.

36. On Ocean Life:
• It is estimated that there will be rise in
sea level by 20 to30 cm by 2030.
• Due to increase in the temperature, the
water expands & require more space.
• It also occur as a result of melting of
glacier.
• Due to global warming the ice extent &
snow cover have decreased.

37. • Scientists use information from several
sources to analyze global warming that
occurred before people began to use
thermometers.
• Computers help climatologists to analyze
past climate change & predict the future
changes.

38. 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

39. 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
* Planting more plants → reduce the
pollutants e.g. CO2

40. What’s being done now to
reduce our emissions?
Wind Power Solar Power Fuel-Efficiency

41. Measures on controlling the problem
Citizens
* Reduce the use of plastic bags → as
degradation of plastic emit CH4
* Recycle the resources, e.g. plastic
* Reduce the use of sprays → as CFCs would
be emitted out

42. Measures on controlling the problem
* Reduce the use of air-conditioner, which will
emit CFCs
* Use public transportation instead of
private cars → reduce the pollutants emitted
by cars