For Grade 5 to 6

1. Welcome To Our
Presentation
Greenhouse Effect

2. • What is Greenhouse?
The greenhouse effect is the process by which radiation
from a planet's atmosphere warms the planet's surface
to a temperature above what it would be without its
atmosphere.If a planet's atmosphere contains radiatively
greenhouse gases, the atmosphere will radiate energy in
all directions. The part of this radiation is directed
towards the surface, warming it. The downward
component of this radiation – that is, the strength of the
greenhouse effect – will depend on the atmosphere's
temperature and on the amount of greenhouse gases
that the atmosphere contains.

3. • History
The existence of the greenhouse effect was argued by Joseph
Fourier in 1824. The argument and the evidence was further
strengthened by Claude Pouillet in 1827 and 1838, and
reasoned from experimental observations by John Tyndall in
1859. The effect was more fully quantified by Svante Arrhenius
in 1896. However, the term "greenhouse" was not used to refer
to this effect by any of these scientists; the term was first used
in this way by Nils Gustaf Ekholm in 1901.
In 1917 Alexander Graham Bell wrote "[The unchecked burning
of fossil fuels] would have a sort of greenhouse effect", and
"The net result is the greenhouse becomes a sort of hot-house.
Bell went on to also advocate the use of alternate energy
sources, such as solar energy.

4. • Mechanism
 The sun radiates solar energy
on earth. The larger part of
this energy (45%) is radiated
back into space. Greenhouse
gases in the atmosphere
contribute to global warming
by absorption and reflection of
atmospheric and solar energy.
This natural phenomenon is
what we call the greenhouse
effect. It is agreed that the
greenhouse effect is correlated
with global temperature
change. If greenhouse gases
would not exist earthly
temperatures would be below
–18 o

5. It is not physically realistic to assign a specific percentage to
each gas because the absorption and emission bands of the
gases overlap. The major non-gas contributor to Earth's
greenhouse effect, clouds, also absorb and emit infrared
radiation and thus have an effect on the radiative
properties of the atmosphere.
By their percentage contribution to the
greenhouse effect on Earth the four major
gases are:
• water vapor, 36–70%
• carbon dioxide, 9–26%
• methane, 4–9%
• ozone, 3–7%
• Greenhouse gases

6. • Role in climate change
• Water vapor: The most abundant greenhouse gas, but
importantly, it acts as a feedback to the climate. Water
vapor increases as the Earth's atmosphere warms, but
so does the possibility of clouds and precipitation,
making these some of the most important feedback
mechanisms to the greenhouse effect.
• Carbon dioxide (CO2): A minor but very important
component of the atmosphere, carbon dioxide is
released through natural processes such as respiration
and volcano eruptions and through human activities
such as deforestation, land use changes, and burning
fossil fuels.

7. • Methane: A hydrocarbon gas produced both through natural
sources and human activities, including the decomposition of
wastes in landfills, agriculture, and especially rice cultivation,
as well as ruminant digestion and manure management
associated with domestic livestock. On a
• Nitrous oxide: A powerful greenhouse gas produced by soil
cultivation practices, especially the use of commercial and
organic fertilizers, fossil fuel combustion, nitric acid
production, and biomass burning.
• Chlorofluorocarbons (CFCs): Synthetic compounds entirely
of industrial origin used in a number of applications, but
now largely regulated in production and release to the
atmosphere by international agreement for their ability to
contribute to destruction of the ozone layer.

8. • The Effects of Greenhouse :
1. The Weather: For greenhouse effect most areas will become
warmer, some areas will become cooler. There may be many
storms, floods and drought. no one can predict which area
will be effected.
2. Sea Levels: Higher temperatures will make the water of the
seas and oceans expand. Ice melting in the Antarctic and
Greenland will flow into the sea. All over the world, sea levels
may rise, perhaps by as much as 20 to 40 cm, by the
beginning of the next century.
3. Farming: The changes in the weather will affect the types of
crops grown in different parts of the world. Some crops, such
as wheat and rice grow better in higher temperatures, but
other plants, such as maize and sugarcane do not.

9. 4.Plants & Animals: It has taken millions of years for life to
become used to the conditions on Earth. As weather and
temperature changes, the homes of plants and animals will be
affected all over the world. Many animals and plants may not
be able to cope with these changes and could die.
5.People: The changes in climate will affect everyone, but
some populations will be at greater risk. The effect on people
will depend on how well we can adapt to the changes and
how much we can do to reduce climate change in the world.

10. • Ways to Reduce Greenhouse Gases
1. Reduce, Reuse, Recycle: Buying products with minimal
packaging will help to reduce waste. By recycling half of our
household waste, we can save 2,400 pounds of carbon
dioxide annually.
2. Use Less Heat and Air Condition: Adding insulation to our
walls and installing weather stripping or caulking around
doors and windows can lower our heating costs more than 25
percent, by reducing the amount of energy we need to heat
and cool our home.

11. 3. Replace Your Light Bulbs: Wherever practical, replace
regular light bulbs with compact fluorescent light (CFL) bulbs.
Replacing just one 60-watt incandescent light bulb with a CFL
will save us TK.30 over the life of the bulb.
4. Drive Less and Drive Smart: Less driving means fewer
emissions. Besides saving gasoline, walking and biking are
great forms of exercise.
5. Buy Energy-Efficient Products: Home appliances now come
in a range of energy-efficient models, and compact
fluorescent bulbs are designed to provide more natural-
looking light while using far less energy than standard light
bulbs.

12. 6. Plant a Tree: If we have the means to plant a tree, start
digging. Trees absorb carbon dioxide and give off oxygen. A
single tree will absorb approximately one ton of carbon
dioxide during its lifetime.
7. Encourage Others to Conserve: Share information about
recycling and energy conservation with our friends,
neighbors and co-workers, and take opportunities to
encourage public officials to establish programs and policies
that are good for the environment.

13. Thank You