describes about global warming

12. The Antarctic Ozone
Hole

13. The Ozone hole as
seen from the Earth

16. ChloroFluoroCarbons

20. Melting and breaking down of
polar ice caps.

21. Artist’s illusion of New York city
underwater.

22. Artist’s illusion of backwards
evolution in case of polar bears.

23. WORLD OZONE DAY
• In 1994, the United Nations General
Assembly voted to designate September
16 as "World Ozone Day", to
commemorate the signing of the
Montreal Protocol on that date in 1987.

26. The greenhouse effect is the process in which
greenhouse gases absorbs radiation (the infra
red rays) and re- radiates it in all directions.
Since part of this re-radiation is back towards
the surface and the lower atmosphere, it results
in an elevation of the average surface
temperature above what it would be in the
absence of the gases.

31. A greenhouse is a structural building with
different types of covering materials, such as
a glass or plastic roof and frequently glass or
plastic walls; it heats up because incoming
visible sunshine is absorbed inside the
structure. Air warmed by the heat from
warmed interior surfaces is retained in the
building by the roof and wall; the air that is
warmed near the ground is prevented
from rising indefinitely and flowing away.
This process in which the heat is trapped
within the greenhouse can be compared to
the way in which the heat radiations are
trapped in the earth’s atmosphere.

32. Green house effect is something that cannot be
prevented but can
be reduced. It can be reduced in the following
ways:
1. By opting for greener technologies that are
eco-friendly.
2. By reducing emissions from automobiles,
the greenhouse gases can be reduced.
3. By preventing deforestation, because plants
absorb a great amount of CO2 from the
atmosphere.
4. By using CFC-free refrigerators.

33. ACID RAIN
Rain Classifier : The Engineered Way of Evaluating the Rain
Acid Rain :
Nature’s “Tears of
Paradise”..

34. ACID RAIN
* Involves deposition of aqueous acids, acidic gases and acidic salts
- Acid deposition has 2 parts: wet and dry
- Wet deposition refers to acidic rain, fog & snow
- Dry deposition refers to acidic gases and particles
- Half of the acidity in the atmosphere falls back to earth through
dry deposition
* Acid rain is a regional air pollution problem
- Canada, & North Western USA are worst affected
- Average pH of rainfall recorded in Toronto in Feb. 1979 is 3.5.
In 1989 fog in Los Angles had a pH as low as 2.2. Most acidic rain
fall in US in Wheeling West Virginia is 1.4.
- Precipitation of clean atmosphere may have 5.6 pH.

35. What are the origins of ACID RAINS ?
Human activities are at the origin of important
quantities of polluting items that are thrown out in the
atmosphere which contibutes to acid rain .
Combustion of fossil fuels like Coal, Firewood
etc which produces air pollutants like sulphur
dioxide and nitrogen dioxide.

36. Gases which are at the origin of acid rains
are :
Sulphur dioxyde Carbon dioxyde Nitrogen oxide

37. Acid rains appear when :
Sulphur dioxyde Nitrogen oxide
Release sulphuric acid and nitric
acid !
They move up into the air and are released
as acid rains