Environment ,global warming,ozone layer depletion

1. Climate Change, Global
Warming Ozone Layer
Depletion Nuclear accidents &
Holocaust
Prepared by
Dr.V.Vidhya

2. Climate Change:
Fitting the pieces
together

3. What is Climate Change?
•Climate is the average weather at a given point and time of
year, over a long period (typically 30 years).
•Climate change is the greatest threat facing our planet
today.
•A warming planet alters weather patterns, water supplies,
seasonal growth for plants and a sustainable way of life for
us and the world’s wildlife.
•Climate change has already started, but it’s not too late to
take action. There’s still time for us all to be part of the
solution.

4. •Changes in:
–Sun’s output
–Earth’s orbit
–Drifting continents
–Volcanic eruptions
–Greenhouse gases
What Changes Climate?

5. “Greenhouse
effect”
Increasing greenhouse gases trap more
heat

7. Other evidence of Climate
Change
•Glacier retreat
1875 2004

8. Why should we care?

9. •Produce more fuel-efficient vehicles
•Reduce vehicle use
•Improve energy-efficiency in buildings
•Develop carbon capture and storage
processes
•Triple nuclear power
•Increase solar power
•Decrease deforestation/plant forests
•Improve soil carbon management strategies
What WE can do?

10. Ozone Layer depletion

11. Ozone Depletion
Significant concentrations of ozone (O3) exist in the
lower elevations of the stratosphere.
Ozone in the stratosphere
absorbs UV B radiation from
sunlight.
UV B radiation damages
DNA molecules and can
cause genetic defects on
the outer surfaces of
plants and animals,
including human skin (skin
cancer)

12. •Ozone depletion is the seasonal loss of a
large swath of our stratospheric ozone
above Antartica, as well as the general
degradation of this protective layer around
the globe.
•With less ozone in the atmosphere, more
ultraviolet radiation strikes Earth, causing
more skin cancer, eye damage, and
possible harm to crops.
Ozone Layer Depletion

13. Ozone Depletion Results
Each 1% loss of ozone leads to a 2% increase
in UV radiation striking the earth.
A 2% increase in UV radiation results in a 5% to
7% increase in skin cancer, including a 1%
increase in deadly malignant melanoma

14. Satellite photo of south pole. Purple shade shows the extent of the ozone
hole.

15. Protecting the Ozone Layer
Ban the use of CFC’s
Have to replace with something
Current replacements are greenhouse gases
and do not eliminate ozone depletion, just
slow it down

16. Air Quality Standards
Emission Standards
Limit amounts of pollutants that can be emitted
by pollution sources
Generally set by State Air Quality Offices

17. Global Warming

18. Global Warming
•Global warming is a Global
phenomenon.
•It refers to a gradual increase in the
temperature of the Earth due to trapping
of green house gases.

19. Green House gases
•Gases such as CO2, SO2, NO2,CH4, etc.
Are the green house gases.
•Most of these are the polluting gases that
are produced by the industries.
•These gases trap the heat from the
sunrays that are reflected from the sun.

20. Why Global Warming
Occurs?
It is the effect of the process of trapping of
Heat due to CO2 which has been going on
since times unknown.
•But due to rapid rise in population over the
last few decades, the CO2 emission has
increased whereas due to deforestation, the
rate of CO2 absorption has gone down thus
disturbing the balance of Nature.

21. Why Global Warming Occurs?
•Also due to Globalization, various
industries started to grow.
•This also led to the problems of
various types of pollutions including air
pollution.
•Most of the gases that pollute the
environment are Green house gases.
•This leads to Global warming.

22. What do climate scientists
really think?

23. Effects of Global Warming
•It has been reported that the temperature of
Earth is increasing each day by few degrees.
•As a result of this, the snow in various regions
of Earth is rapidly melting.
•This may add more water to fresh water
reserves like lakes and rivers in the beginning
but when the “meltdown” is completed, there
would be no fresh water reserves.
•Also it destroys the ecosystem in the Polar
region.

24. Prevention Of Global Warming
•The various ways to control Global
Warming are:-
1.Control of population. But, since it is not
possible to control population, the best way
to control Global warming is by planting
trees.
2.Use of ecofriendly and biodegradable
products.
3.Avoid using vehicles when not necessary.

25. 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.

26. 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.

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

28. 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

29. NUCLEAR
ACCIDENT

30. Nuclear accidents and nuclear inci
dent
⦿A nuclear accident
or nuclear incident, depending
on the severity, is
known toinadvertent releases of
radioactive materials,
accidental or radioactivity
levels likely to
harm public health.

31. Nuclear accidents and nuclear inci
dent
⦿Is described as a nuclear
accident or incident according to its
severity and its impacton the population and the environment.
⦿Radiological accidents can happen at a nuclear plant
or outside, ie in a facility thatconducts
a nuclear activity (hospitals, research laboratories ...) or
due to the loss of a radioactive
source, or by spreading involuntary or voluntary radioactive
substances intothe environment.
⦿To measure the severity of an event, there is an
international scale: INES scale.

32. International Nuclear
Event Scale

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EARTH…..
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LIFE……….
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