This is about the environmental change concerns. The different layers of the atmosphere have been described in this ppt. It is very easy to understand about the layers from this presentation

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Climate Change Concerns

2. The Atmosphere of Earth
Earth
Atmosphere
•The atmosphere of earth is the layers of gases, commonly
known as air, that surrounds the earth.
•The air/ atmosphere is retained due to gravity around the
earth.
•By volume, dry air contains 78.09% Nitrogen, 20.95%
oxygen, 0.93% argon and 0.04% carbon dioxide.
Atmosphere also contains water vapours.
•The earth’s atmosphere is about 480 Km thick and most
of it is within 16 Km. The atmosphere becomes thinner
and thinner with increasing altitude, with no definite
boundary between the atmosphere and outer space.
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3. Is Atmosphere Part of Earth??
The thermosphere is considered as a part of Earth’s atmosphere, but the air density is
so low that most of this layer is what normally thought of as outer space. In fact, this is
where the space shuttles flew.
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4. Layers of Atmosphere
• 99% of layers are confined into first 32 Kms.
Layers of Atmosphere
Thermal Layer
(This layer
exists with the
earth)
Magneto- Electrical
Structure
(Layer which surrounds
the earth).
* Most of the scientists,
do not consider this as the
layer of the earth. So, still
its controversial, whether
to consider this as a layer
of atmosphere or not.
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5. Thermal Layers
Troposphere Layer
Tropopause
Earth
*Tropopause: The upper boundary of the troposphere layer. Here pause means upper layer of
the boundary.
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6. Thermal Layers
Homosphere
Uniform mixing of gases. It
includes lower layers such as
troposphere, stratosphere
and mesosphere.
Hetrosphere
Non uniform mixing of
gases.
Troposphere
Stratosphere
Mesosphere
Nitrogen
Oxygen
Thermosphere
Helium
Hydrogen
Hetrosphere
Homosphere
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7. Layers of the Thermal Structure
Troposphere
•It is the lowest region of the
atmosphere. It extends from
the earth’s surface to a height
of 6-10 Km.
•All the weather conditions
take place in this layer.
•Formation of clouds is in
this layer.
•From the temperature point
of view it can be seen that
with the increase of altitude
the temperature is
decreasing.
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8. Layers of the Thermal Structure
Stratosphere
•This layer extends from 15 too 55
Km.
•The major phenomena in this layer is
the presence of Ozone.
•This Ozone layer shields the harmful
UV rays that comes from Sun.
•The Ozone in the troposphere is a
pollutant.
•There are no clouds in the
stratosphere and the
•Wind blows in horizontal direction.
•From the temperature point of view
it can be seen that the temperature for
the initial 9 Km from the tropopause
is constant and after that it starts
increasing.
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9. Layers of the Thermal Structure
Mesosphere
•This layer is up to 80 Km.
•Most of the shooting of stars
occurs here.
•There is decrease of temperature
and it is the coldest layer.
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10. Layers of the Thermal Structure
Thermosphere
•It extends from 80 Km to the outer space.
•This is the part of Hetrosphere.
•Highly dense gases are below the thermosphere
and low dense gases are above them.
•There has an increase of temperature with the
altitude and this is due to low density molecules.
•The temperature rise reaches up to 1200oC.
•Space shuttles are in this region.
Nitrogen
Oxygen
Thermosphere
Helium
Hydrogen
Hetrosphere
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11. Exosphere
Exosphere is a thin, atmosphere like volume surrounding a planet, where the molecules
are gravitationally bound to that body, but where the density is too low for them to
behave like a gas by colliding with each other.
Helium is the most commonly available gas in the exosphere. It ranges from 400 to
1000 Km. Temperature available is 5568oC.
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12. Ionosphere
For the ionosphere there is no starting point, however it has been considered that
ionosphere starts from mesosphere and it ranges from 60-1000 Km. Further, the
ionosphere is divided into 3 layers: D,E,F.
D layers: It can be seen in day only. It absorbs hard
X-Rays.
E layers: It absorbs in soft X-rays and is
particularly seen in night.
F layers: They absorbs the UV rays. F2 layers,
propagation of radio waves at high frequency.
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Magneto- Electrical Structure
Radiation Belt: It is the zone of
energetic charged particles. Most
of which are originated from Sun
wind.
Magnetopause: The region where
the solar wind strikes to the outer
layer of earth’s magnetic filed.
When the solar wind strikes to the
bow shock and magnetosheath,
they gets heated due to which they
change their path. Due to which
we can see the magnetotail.
Plasmasphere: It is mainly made
up of plasma. The fourth stage of
matter

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Aurora
An aurora, sometimes referred to as polar lights,
northern lights (aurora borealis) or
southern lights (aurora australis),
is a natural light display in the Earth's sky

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Global Temperature
The common definition of climate suggests that it is the prevailing or average weather
of a place as determined by temperature and other metrological conditions over a
period of time.

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Global Temperature Model

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Green House Effect
Shorter Wavelength
Longer Wavelength
Shorter wavelength: high
frequency, high energy.
Longer wavelength: low
frequency, low energy
First discovered by Joseph Fourier
in 1824.
First experimented by John
Tyndall in 1858.
First reported quantitatively by
Svante Arrhenius in 1896.

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Green House Effect
90% Visible and IR
30% is the albedo.
70 % is reaching to the earth
surface.
Out of 70% , 19% goes back to
atmosphere and 51% absorbed
by land and water.
SUN

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Green House gases
The gases which helps in predominantly in heating are known as green house gases.
Most common GHG are: CO2, CH4, SO2, N2O, CFC, HCFC etc.
On the basis of absorption capability:
N2O has 271 times more absorption capability than CO2.
CH4 has 21 times more absorption capability than CO2.

20. Greenhouse Gas Emissions
• Animal agriculture, manure,
natural gas, rice paddies,
landfills, coal, and other
anthropogenic sources
contribute about 450 million
tons of methane each year
• Atmospheric concentrations of
CO2 and CH4 have increased by
31% and 149% respectively
above pre-industrial levels since
1750
• Combustion of fossil fuels: coal-burning power plants, automobile
exhausts, factory smokestacks, other waste vents of the human
environment contribute 22 billion tons of carbon dioxide and other
greenhouse gases each year

21. Power Plants
40% of carbon dioxide emissions stem from the burning of fossil fuels for the purpose of electricity
generation
Cars
20% of carbon dioxide emissions comes from the burning of gasoline in internal-combustion engines of
cars and light trucks with poor gas mileage contribute the most to global warming
Trucks
Another 13% of carbon dioxide emissions come from
trucks used mostly for commercial purposes
Airplanes
Aviation causes 3.5 percent of global warming,
and the figure could rise to 15 percent by 2050
Carbon Dioxide from Buildings
Buildings structure account for about 12% of
carbon dioxide emissions
Greenhouse Gas Emissions

22. Methane
• Methane is more than 20 times as effective as CO2 at trapping heat in the atmosphere
• 2004 Levels of atmospheric methane have risen 145% in the last 100 years
• Derived from sources such as rice paddies,bacteria in bogs and fossil fuel
production
• In flooded fields, anaerobic conditions develop
and the organic matter in the soil decomposes
Nitrous oxide
• Naturally produced by oceans and rainforests
• Man-made sources-nylon and nitric acid
production, the use of fertilizers in agriculture,
cars with catalytic converters and the burning
of organic matter
Deforestation
• Responsible for 25% of all carbon emissions
entering the atmosphere by the burning and cutting of about 34 million acres of trees each
year
Greenhouse Gas Emissions

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Proportion of Green House gases
Water vapors:- 36 to 76%
CO2 :- 9 to 26%
CH4:- 4 to 9%
O3 :-3-7%

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Global Warming
When there has an increase in temperature of earth’s surface, this is known as global warming
and the global warming can be measured by an indicator which is known as global warming
potential.
•Global warming potential is a relative measure of heat being trapped a green house gas in the
atmosphere
•Compares the total heat trapped by certain mass of gas to total amount of heat trapped by a
similar mass of CO2.
•GWP is being measured within a time span of 20, 50, 100 years. It varies from region to region

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Global Warming Potential
2 2
0
0
. ( )
. ( )
t
g g
t
CO CO
F R t dt
GWP
F R t dt





It is a ratio of cumulative radiative forcing for 1 kg of a GHG over some period of time
to the cumulative radiative forcing for 1 kg reference gas, chosen to be CO2, over the
same period of time.
Mathematically, it is given as
Where
Δ Fg = radiative forcing of GHG in question per kg (W/m2/kg)
Δ FCO2 = radiative forcing of CO2 in question per kg (W/m2/kg)
Rg (t) = fraction of 1 kg of GHG remaining in the atmosphere at time t.
RCO2 (t) = fraction of 1 kg of CO2 remaining in the atmosphere at time t.
t = time period for the cumulative effect.

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Factors on which Global Warming Potential depends
•The absorption of the infrared radiation by a given species.
•The spectral location of its absorbing wavelength
•The atmospheric lifetime of the species.

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Climate change and concerns
The variation and shifts in weather conditions over space and time of different scales and
magnitude resulting into change of climate type is defined as climate change. E.g. from warm and
moist climate to warm and dry climate.
The rate of climate change depends on the nature of casual factor, which may be gradual or rapid,
short or long, local, regional and global scale.
Factors affecting the climate change are:
1) Natural factors
2) Anthropogenic factors

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