Layers of Atmosphere, Ozone layer, Acid rain, Climate change and efforts to control the effects of climate change

1. Atmosphere
• The atmosphere is a layer of gases and dust particles
around our earth.
• The earth has acceleration due to gravity. The atmosphere
contains 78% of N2, 21% of O2, 0.3% of Co2 by its volume.
Atmosphere extends above 1600 Km from the earth.
• The atmosphere is divided into five layers. They are:
• Troposphere
• Stratosphere
• Mesosphere
• Thermosphere
• Exosphere
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2. Atmosphere
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4. Troposphere
• The first layer of the atmosphere which is extended up
to 60 km height from the earth’s surface.
Features:
• It is the lowermost layer of the atmosphere. This layer
lies nearest to the surface of the earth.
• The topmost layer of the troposphere is called the
tropo-pause. It separates the troposphere and
stratosphere.
• Its average temperature is -56*C.
• It is a layer where weather formation takes place.
• It is a layer where the cloud is formed, and lighting
takes places.
• The temperature decreases by 6.5°C per kilometer
height, etc.
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5. Stratosphere
• The layer of atmosphere between troposphere
and mesosphere is known as the stratosphere.
• The layer extends from 16 km to 50 km
vertically upward the earth’s surface.
• There is a temperature of about -55oC to -
75oC.
• It contains the ozone layer which protects the
earth from harmful rays coming from the sun.
• Its outermost boundary layer is called strato-
pause.
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6. Mesosphere
• The layer of atmosphere between
stratosphere and thermosphere is known as
mesosphere. It lies between 50- 80 km from
the surface of the earth.
• In this layer, temperature is decreased by
height.
• Meteors burn out, etc.
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7. Thermomsphere
• The layer of atmosphere which lies between
mesosphere and exosphere is called thermosphere.
• It lies in the altitude of 80–720 km from the surface of
the earth.
• Since there is more effect of solar radiation in these
regions, the temperature is high.
• Gas molecules split in ions in this layer. So this layer is
known as ion layer.
• In this layer density of the gas(air) is low.
• Its upper surface has H2 and He and lower surface have
N2 and O2 in a small amount, etc.
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8. Exosphere
• It is the outermost layer of the atmosphere
located above 720 km from the surface of the
earth.
• It is also called the fringe region.
• There is no effect of gravity in this layer.
• The temperature of this layer varies from
1200°C to 6000°C
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9. Ozone Layer
• The ozone is a gas with three oxygen atoms is known as the Ozone layer.
• The ozone layer is found in the stratosphere. It is extended from 16 km to
50 km above the earth surface. Its thickness is 34 Km.
• This layer is clear and cloudless and jet planes fly in this layer. This thick
layer of air absorbs most of the solar radiation.
• Due to the absorption of solar radiations, the temperature of the
stratosphere increases as the increase in altitude.
• The ozone layer protects earth from harmful radiation and if there is ozone
layer depletion then rays of sun enter earth without any obstacle which
causes the rise in temperature of the earth.
• Features:
a) Its molecular formula is O3.
b) This layer present in Stratosphere.
c) It is a protective layer because it absorbs 99% harmful UV radiation, etc.
Ozone layer formation:
O2 ——-UV radiation——-> O+O
O2 ——-UV radiation——-> O3(Ozone)
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10. Importance
• It absorbs 99% harmful UV radiation.
• It establishes a balance between temperature
and weather.
• It protects the chlorophyll of plant from
burning.
• It protects us from skin cancer, blindness, etc.
• It safes aquatic animals, etc.
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11. Ozone Layer Depletion
• The ozone layer depletion is a process in which the ozone
layer becomes thin and UV radiation easily penetrates and
come to earth.
• The main cause of ozone layer depletion is the chemical
substance produced by the human.
• Chlorofluorocarbon is the major chemical substance which
destroys the ozone layer.
• Along with this, chlorinated compounds such as methyl
chloroform, carbon tetrachloride, methyl bromide etc. also
destroy the ozone layer.
• CFCs (Chlorofluorocarbons) emitted from foam, aerosols,
refrigerator, air conditioner, fire extinguisher, etc.
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12. Process of ozone layer depletion
• CF2 Cl2 —— UV rays ——> CF2Cl+Cl
(Nascent/atomic chlorine)
O3+cl —— UV rays —–> ClO+O2
O3+O —— UV rays —–> O2+O2
• ∴ The nascent chlorine or atomic chlorine is
responsible for ozone layer depletion.
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13. Ozone Layer
• Formation • Depletion
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14. Effects of Ozone layer depletion
• Effect of Ozone layer depleting:
a) Human beings: Cancer, Blindness, loss of
immunity power.
b) Aves: It decreases egg laying capacity and
the egg becomes thin shelled.
c) Aquatic animals: Mostly destroyed.
d) Vegetation: The chlorophyll is destroyed
and most of the plants are lost, etc.
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15. Conservation of Ozone layer
• The production and use of CFC should be banned.
• The alternatives for the CFCs should be
developed.
• The release of oxides of nitrogen should be
avoided.
• Reduce the use of chemical fertilizer.
• We should replace fossil fuel by using the
alternating source of energy.
• We should promote public vehicles rather than
private vehicles, etc.
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16. Greenhouse
• The artificial house which is design for cultivating long day
plants in short day region of the world is called
Greenhouse.
• The greenhouse is made up of glass and plastics which
allows the light to pass through it but does not allow the
light to escape.
• The greenhouse effect is the phenomenon of increasing the
temperature of the earth’s surface as in the artificial
greenhouse.
• It is required to maintain the temperature of the earth’s
surface. The over greenhouse effect made lead to increase
in temperature, global warming, affect in the environment
and so on.
• The greenhouse is the process of tapping the radiation of
the sun and making the atmosphere warm. It causes global
warming as it increases the temperature of the earth.
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17. Greenhouse Gases
• The gases like carbon dioxide, Nitrous Oxide, Methane, sulfur
dioxide, chlorofluorocarbons prevent the return of ultraviolet
radiation from the earth and cause the increment of a temperature of
the earth.
• So, those gases are called Greenhouse gases.
a) CO2
b) N2(Nitrous oxide)
c) CH4 (Methane)
d) SO2 (Sulfur dioxide)
e) Ozone (O3)
f) Water vapor (H2O) etc.
• Disadvantage of the Greenhouse:
a) Global warming
b) Acid rain
c)Change in Weather pattern, etc.
• Advantage of Artificial greenhouse
• Different crop plants can be grown in off-seasons.
• Summer plants can grow in winter seasons
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18. Effects of Greenhouse
• The gases like carbon dioxide, Nitrous Oxide, Methane,
sulfur dioxide, chlorofluorocarbons let the entrance of the
ultraviolet radiation but stop them exist.
• As a result, the ultraviolet radiation changes into heat
which causes an increment of a temperature of the earth is
called the greenhouse effect.
• It absorbs the solar as well as the earth’s existing heat
which increases the surface temperature of the earth.
• Increase in the temperature forces the ecosystem to
change which affect the biodiversity.
• As a result of the greenhouse effect, it increases the
temperature and affects the water cycle.
• The greenhouse effect increases the temperature which
results in the meltdown of polar ice caps along with global
warming.
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19. Acid Rain
• Falling of acid along with water during rainfall is called acid rain.
• Process of acid formation:
• H2SO4 Formation:
SO2 + O2 ——–> SO3 (Sulphuric oxide)
SO3 ——-> H2SO4
• HNO3 formation:
NO (Nitric oxide) + O2 ——-> NO2 (Nitrogen dioxide)
NO2 + O2 ——-> N2O5 (Nitrogen pentaoxide)
N2O5 ———> HNO3
• H2Co3 Formation:
CO2 + H2O ——-> H2CO3
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20. Acid Rain
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21. Industrial gases
• The thick layer of gases produced by industries are
called industrial gases. So2, Nitrogen oxide, etc
• In the process of industrial production, different types
of toxic gases, lead, metal, complex organic
compounds, etc. are released.
• These gases produced in industrial production are
known as industrial gases.
• Due to the increase in industrial gases, the air gets
polluted.
• Along with that, it also affects the weather.
• When rain falls on the earth’ surface, due to the
presence of industrial gases, acid rain occurs.
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22. Effects in Air
• Industrial smog: Industrial smog is the cloud
of smoke gases solid and liquid particles
released by industries.
• Climate change: The change in the change in
the statistical distribution of weather patterns
when that change lasts for extended periods is
called climate change.
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23. National Efforts in Nepal
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25. 2.Local Adaptation Program of Action
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26. International Efforts
• Agenda-21: The work plan think globally and act locally was
brought in practice to address the issues of climate change and
sustainable development in the 21st century is called Agenda-21.
• Kyoto Protocol: The Kyoto protocol is the international carbon
emission reduction agreement.
• Efforts made on the international level:
• United Nations Convention about climate change.
• Conference of the Concerned and the Recognized Countries about
climate change.
• Agenda-21.
• Kyoto protocol.
• Intergovernmental forum.
• Methods of minimizing the emission of greenhouse gases according
to the Kyoto Protocol.
• Minimizing the carbon emission resulted due to deforestation, etc.
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30. Review
• Name the layer of the atmosphere where cloud and fog
formation occur.
Ans: Stratosphere.
• Streaks of hot gases released from meteors are seen.
Ans: Mesosphere layer.
• Gases ionize to form positive ions and electrons.
Ans: Thermosphere.
• Sun’s ultraviolet radiation are absorbs.
Ozone layer.
• Frequent storm ozone.
Ans: Mesosphere.
• Temperature range between -109°C to 1500°C.
Ans: Mesosphere.Anjan Nepal

31. Review
• Give the reasons:
• a) The greenhouse effect is advantageous as well as
disadvantage.
Ans: Greenhouse absorbs heat then its warm in winter in
summer it makes 2X heat. Hence, The greenhouse effect is
advantageous as well as disadvantage.
• b) Temperature increases remarkably in the stratosphere.
Ans: Temperature increases remarkably in the stratosphere
because of temperature gradually increase in height.
• c) Ozone layer must be conserved.
Ans: Ozone layer must be conserved because it prevents UV
rays.
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32. Review
• d) It is better not to use a refrigerator with CFC.
Ans: It is better not to use a refrigerator with CFC because
greenhouse’s covered layer reflect inside ray but outside not share
rays.
• e) The thermosphere is also known as the ionosphere.
Ans: The thermosphere has the direct effect of solar radiation, so
gases are ionized. Hence, The thermosphere is also known as the
ionosphere.
• f) The exosphere is also known as the fringe region.
Ans: Exosphere varies from 1200°C to 6000°C. Hence, The
exosphere is also known as the fringe region.
• g) Stratosphere is also known as Ozonosphere.
Ans: Ozone layer absorbs UV radiation and protects us from the
hazardous effect of UV. Hence, Stratosphere is also known as
Ozonosphere.
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