& CARBON CYCLE
The earth is covered in a blanket of
gases called the atmosphere. Without the
atmosphere no living thing can survive.
The atmosphere gives us warmth by the
natural greenhouse effect. It gives us
air to breath. It protects us from the
Sunís harmful rays and much much more.
Atmospheric layers & gases
Scientists have divided the Earthís
atmosphere into 6 layers. The first
layer is the troposphere. The
troposphere is 0-17 km high. On top of
the troposphere is the stratosphere. The
stratosphere is 17-50 km high. After the
stratosphere is the mesosphere. The
mesosphere is 50-85 km high. Then comes
the thermosphere which is 85-300 km.
then comes the ionosphere. After that is
the exosphere which is more than 500 km
There are about 5 important gases.
Nitrogen (78.1%), oxygen (20.9%), argon
(0.9%), carbon dioxide (0.039%) and
water vapor (3%).
Carbon dioxide is necessary for plants
to live and it also act as greenhouse
gas thereby keeping the Earth warm
enough to sustain life. But if the
carbon dioxide level goes up more than
what it already is it will start to warm
up the Earth. more than its normal
temperature. If the level of carbon
dioxide keeps on raising it will
raise the temperature of Earth which
could lead to melting of polar ice cap
which then can increase the water level.
This can lead to many coastal cities and
even many island countries go
Plants use carbon dioxide to produce
sugar. This process is called
photosynthesis. While producing their
food through photosynthesis they
generate oxygen which all animals on
Earth use for respiration.
The Carbon Cycle
In the atmosphere, carbon is attached to
some oxygen in a gas called carbon
Plants use carbon dioxide and sunlight
to make their own food and grow. The
carbon becomes part of the plant. Plants
when die and are buried may turn into
fossil fuels made of carbon like coal
and oil over millions of years. When
humans burn fossil fuels, most of the
carbon quickly enters the atmosphere as
What blocks the Sunís energy from
escaping from the Earth? Unlike a
greenhouse, the Earth does not have a
layer of glass over it! Instead,
molecules in our atmosphere called
greenhouse gasses absorb the heat.
Greenhouse gasses include water vapor,
methane, ozone, nitrous oxide, and
carbon dioxide. There may not be much of
some of these gasses in our atmosphere,
but they can have a big impact. Each
greenhouse gas molecule is made of three
or more atoms that are bonded loosely
together. These molecules are able to
absorb heat, which makes them vibrate.
They eventually release the heat energy
and it is often absorbed by another
greenhouse gas molecule.
The greenhouse effect is useful because
trapping some energy keeps the
temperatures on our planet mild and
suitable for living things. Without its
atmosphere and the greenhouse effect,
the average temperature at the surface
of the Earth would be zero degrees
Fahrenheit. However, too many greenhouse
gases can cause the temperature to
increase out of control. Such is the
case on Venus where greenhouse gases are
abundant and the average temperature at
the surface is more than 855 degrees
Fahrenheit (457 degrees Celsius).
End Result Of Human Action On Earth
The Earth as we know it is slowly
warming up which may result in global
warming and climate change leading to
extinction of many animal and plant
species including humans. And this all
is happening due
increase in carbon dioxide and other
green housegasses in the atmosphere.
Also due to human actions the ozone layer is breaking and
the Sunís harmful Ultraviolet rays are
entering the Earth. If this increase in
CO2 and other gases doesnít stop all
living things including humans may
become extinct in near future. We must
do something to stop global warming as
soon as possible.
About The Author:
This article is written by Dave Bhardwaj a
12 years old (Grade 7) student. For more
articles from Dave