Greenhouse effect raises the carbon dioxide level and leads to global warming. The ozone layer gets thinner due to CFCs.

1. Green house Effect & Ozone Depletion – Grade 9
Dr. Pramila Kudva

2. Green House Effect

3. How does
the
greenhouse
effect work?
In the daytime, sunlight shines into the
greenhouse and warms the plants and air
inside. At night time, it's colder outside, but
the greenhouse stays pretty warm inside.
That's because the glass walls of the
greenhouse trap the Sun's heat.
Gases in the atmosphere, such as carbon
dioxide, methane, water vapour trap heat just
like the glass roof of a greenhouse. These
heat-trapping gases are called green house
gases.

4. Green
house Gases
• Nitrous oxide
• Chlorofluoro Carbons
• Carbon dioxide
• Methane
• Water vapour

6. Energy supply
Industries
Rice cultivationDeforestationLandfills
Incinerator
Transportation
Sources of Greenhouse Effect
Urbanization
Livestock

7. Nitrous
oxide
• soil cultivation practices, especially the use of commercial and organic fertilizers, fossil fuel
combustion, nitric acid production, and biomass burning.
Methane
• decomposition of wastes in landfills, agriculture, and especially rice cultivation, as well as
ruminant digestion and manure management associated with domestic livestock.
Carbon di
oxide
• Released through respiration, volcanic eruptions and through human activities such
as deforestation, land use changes, and burning fossil fuels
Chlorofluoro
carbons
• common source of CFCs are refrigerants, but fire suppression systems for aircraft and
aerosols also emit CFCs into the atmosphere.

9. Effects of Global warming Pg 1of 2
• Permafrost thawing could lead to global warming by releasing
methane and other hydrocarbons, which are powerful greenhouse
gases. It also could encourage erosion because permafrost lends
stability to barren Arctic slopes.
• Polar ice caps will melt leading to a rise in the ocean levels and low
lying areas could disappear beneath the waves.
• Increase in global temperatures may lead to climate change.
• It could lead to more diseases since increased temperatures might
lead to growth of micro organisms.
• Species may become extinct. Wild fires may increase.
• Economy might suffer due to low production, Poverty might increase

10. Effects of Global warming Pg 2 of 2
• The rise in temperature will bring about a fall in agricultural produce.
• Bring about changes in habitat – extreme weather conditions-
droughts, floods etc. could affect the flora and fauna
• Moderate warming and more carbon dioxide in the atmosphere may
help some plants to grow faster. However, more severe warming,
floods, and drought may reduce yields.
• Livestock may be at risk, both directly from heat stress and indirectly
from reduced quality of their food supply.
• Fisheries will be affected by changes in water temperature that make
waters more hospitable to invasive species and shift the ranges or
lifecycle timing of certain fish species.

11. Ozone Depletion / Ozone Hole video

12. Global
warming and
Ozone
depletion
Ozone (O3) depletion does not cause global
warming; human activities that release
pollutants into the atmosphere alter it.
Global warming is caused primarily by too
much of green house gases.
Ozone depletion occurs when
chlorofluorocarbons (CFCs) are released into the
atmosphere.
Ozone is in the upper atmosphere and absorbs
UV radiation, CFCs cause chemical reactions that
break down ozone molecules.

13. Good vs Bad Ozone
• Ozone is found in two different parts
of our atmosphere. Ground level or
“bad” ozone is a human health
irritant and component of smog. It is
found in the lower atmosphere
(troposphere) and has nothing to do
with the "ozone hole."
• High level or “good” ozone occurs in
the stratosphere and accounts for
the vast majority of atmospheric
ozone.

14. Ozone hole
• The term ‘ozone hole’ refers to the depletion of
the protective ozone layer in the upper
atmosphere (stratosphere) over Earth's polar
regions. Discovered in 1980s.
• People, plants, and animals living under the ozone
hole are harmed by the solar radiation now
reaching the Earth's surface—where it causes
health problems, from eye damage to skin cancer.

15. How does Ozone depletion occur
Ozone Depletion. When chlorine and bromine atoms come into contact
with ozone in the stratosphere, they destroy ozone molecules. One chlorine
atom can destroy over 100,000 ozone molecules before it is removed from
the stratosphere.

16. What does Ozone Depletion do?
Increases the UV
radiation leading to
sunburn, cataract,
skin cancer.
Weakens the
immune systems
Affects the ability of
the plants to
capture light energy.
Reduces the
nutrient content and
the growth of the
plants. Eg.
Legumes, cabbage.
Plant and animal
plankton are
damaged by the UV
rays.
Zooplankton form
the basis of the
marine food chain.
This affects the fish
production.
Atmospheric
changes induced by
pollution lead to
global warming.

17. Ways to control ozone depletion
Replace halon fire
extinguishers with
alternatives
Check ACs, refrigerators
should be regularly
checked for leaks
Try to create awareness to
recycle the old CFC
products. Ensure the
technicians don’t release it
into the atmosphere.
Subsidize production of
safer alternatives, Find
alternate sources of fuel
Reduce vehicle using fossil
fuel, Produce more fuel-
efficient vehicles
Decrease deforestation

18. The 1987 Montreal Protocol on Substances
that Deplete the Ozone Layer is a landmark
agreement that has successfully reduced the
global production, consumption, and
emissions of ozone-depleting substances
(ODSs). - Phase out the technology using CFC
Montreal Protocol
While the Montreal Protocol was established
to phase out substances that deplete ozone,
the Kyoto Protocol was set in place to reduce
the emissions of greenhouse gases. - HFCs
could also be replaced with alternatives like
carbon dioxide, Ammonia and
Hydrofluorolefins

19. Ocean
acidification
All plants — from giant trees to tiny phytoplankton in the
ocean — take in carbon dioxide and give off oxygen.
Increased carbon dioxide in the ocean changes the water,
making it more acidic. This is called ocean acidification.

20. What is
acid rain?
Precipitation
with acidic
components,
such as sulfuric
or nitric acid
that fall to the
ground. - rain,
snow, fog, hail
or even dust
that is acidic.

21. Effect of Acid Rain

22. Questions
• How does the Green house Effect work? Which are the green house
gases?
• What are the sources of green house effect?
• What are the sources of green house gases?
• What is ocean acidification?
• What is meant by global warming and ozone depletion?
• What causes ozone depletion? How does it occur?
• What are the effects of ozone depletion?
• What are the ways to control ozone depletion?
• What is acid rain and what are its effects?

23. Case studies – make a proper plan with objectives and the methodology draft for
approval before beginning the case study.
1. Delhi introduced odd , even number vehicles to bring down the emission
levels and combat the smog. – refer your text page 83. Is that a a viable
option? State reasons to justify.
What other effective measures would you suggest ? Justify your reasons.
2. Survey what the students feel about deforestation. Explore the impact of
deforestation in terms of climatic change.
3. What Is the Best Way to Reduce Fuel Use in our Community?
4. Prepare posters to create awareness about citizens responsibility to
reduce global warming.
5. Tajmahal was affected by the effluents of Mathura refinery. What
measures would you suggest to overcome this effect on the marble?
6. Why did Kyoto Protocol fail?