Environmental issues like Global warming and Ozone depletion

1. ENVIRONMENTAL ISSUES LIKE
GLOBAL WARMING AND
OZONE DEPLETION
BY : SONANI PARTH (09)
LIMDIWALA ISHA (10)
SARVAJANIK COLLEGE OF ENGINEERING & TECHNOLOGY

2. CONTENTS
• Global Warming
 Definition
 Causes
 Green House Effect
 Problems
 Remedies
• Ozone Depletion
 Definition
 Causes
 Effects
 Steps taken
• Conclusion

3. What is Global Warming ?
• The phenomenon of gradual increase in average temperature of
earth’s atmosphere is known as Global Warming.
• Average temperature around the world have risen by 0.75°C over
the past 100 years about two thirds of this increase has occurred
since 1975.
• The Global Warming is also some times referred to as abrupt
climate change.

4. Causes behind Global Warming
• Industrial pollution
• Deforestation
• Increase in Green House Gases
• Population explosion
• Over use of Fossil Fuels

5. Green House Effect
• The Green House Effect is the process
by which radiation from a planet’s
atmosphere warms the planet’s surface
to a temperature above its normal
temperature.
• It is caused by green house gases like
carbon dioxide (CO₂), Water vapor
(H₂O), Methane (CH₄), Nitrous oxide
(N₂O), Ozone (O₃), Chlorofluorocarbons
(CFCs), etc…
• The mains causes behind their emission
is industrial smoke, automobiles, ACs,
Refrigerators, etc…

6. Problems because of Global Warming
• Increase in sea levels
• Less rain and more drought situation
• Extinction of wild life
• More aggressive and frequent hurricanes
and cyclones
• Lesser production of food grains and
vegetables
• Human deaths because of Heat strokes
etc..

7. Remedies to prevent further damage
• Industrial smokes should be controlled and filtered before releasing it to
the atmosphere.
• Alternate cooling agents should be used in air conditioners and
refrigerators which are not harmful to atmosphere.
• People should prefer less use of private vehicles and more use of public
transport that could lead to less pollution.
• Renewable energy resources should be preferred like solar energy.
• Less use of carbon emitting fuels.
• Many countries like India, Japan, UK etc. have signed the agreements on
creating less pollution and helping in creating a better environment.

8. Ozone Layer Depletion
• Ozone depletion describes the phenomena
observed since the late 1970s : a steady
decline of about 4% in total amount of
ozone in Earth’s stratosphere.
• Ozone layer protects Earth from harmful
UV rays.
• The emission of ODS (Ozone Depleting
Substances) account for roughly 90% of
total depletion of ozone layer in
stratosphere.
• The depletion takes place in the form of
holes known as ozone hole.

9. Causes behind Ozone Depletion
• The main cause behind these Ozone Depletion or Ozone hole is
man-made chemicals, especially man-made halocarbon
refrigerants, solvents, propellants, HFCs, CFCs etc.
• The above ODS are transported into the stratosphere by winds
after being emitted at surface.
• Once in the stratosphere, they release halogen atoms through
photodissociation, which catalyze the breakdown of ozone(O₃)
into oxygen(O₂).

10. Effects of Ozone Depletion
• Ozone Depletion has generated worldwide
concern over increased cancer risks and other
negative effects.
• The Ozone layer prevents the most harmful UVB
wavelengths of ultraviolet light (UV light) from
passing through the Earth’s atmosphere.
• These wavelengths causes skin cancer, sunburn,
cataracts etc. apart from these it is also harmful
for plants and animals.
• The melting of polar ice is also result of ozone
depletion.
• Many marine life is endangered because of the
thinning of the ozone layer.
Image of largest
Antarctic ozone hole
( September 2006)

11. Steps taken against the Ozone Depletion
• The concerns regarding the gradual loss of ozone in the
atmosphere led to the adoption of the Montreal Protocol in 1987,
which bans the production of CFCs, halons, and other ODS.
• The ban came into effect in1989. Ozone levels stabilized by the
mid-1990s and began to recover in the 2000s.
• Recovery is projected to continue over the next century and the
ozone holes are expected to completely filled by the 2075.
• The Montreal Protocol is considered the most successful
international environmental agreement to the date.

12. Conclusion
• It’s because of the environment that we are alive
so every little action we take to protect and
preserve our Environment is of the utmost
importance.
• It’s the Environment cycle, we hurt the nature
and it is going to come back sooner or later with
more aggression, taking lives of many people by
Natural disasters.
• Every year 5th June is celebrated as World
Environment Day to make people understand the
importance of the nature
• “ There is enough in the world for everyone’s
need, but not enough for everyone’s greed.” –
Mahatma Gandhi