Cfcs Cause Deterioration of the Ozone Layer


The deterioration of the ozone layer , caused by Cfcs, endangers the
lives of humans'. Cfcs have a diminishing effect on the ozone layer.
Furthermore, the deterioration of the ozone cause an increase of Ultraviolet
(UV) radiation which can have a negative effect on human skin and eyes. As a
writer for newsweek, I have investigated the scenario and found the following
information.
The earth's atmosphere is a blanket of air that surrounds the planet.
This atmospheric air is made up of many different gases, 78% nitrogen, 21%
oxygen, and 1% of a dozen or more other gases like carbon dioxide, helium, and
ozone.
This atmosphere extends many miles out from the earth's surface.
However, this layer is not a uniform layer, from top to bottom. As one moves
out from the planet's surface the atmosphere becomes progressively dense. This
atmosphere can be divide into four major regions.
The first region is the troposphere which extends about 6.5 miles above
the planet's surface. The troposphere contains the oxygen that we breath and is
where a majority of our weather takes place.
Beyond the troposphere is the second region of the atmosphere, the
stratosphere. The stratosphere extends from roughly 6.5-30 miles from the
earth's' surface. The air on this region is much less dense than in the
troposphere, and it's a lot drier. The stratosphere is the area that contains
the majority of the ozone layer.
Past the stratosphere is the mesosphere which extends to 50 miles above
the planet. The last region is the thermosphere. The thermosphere's outermost
edge is roughly 600 miles above the surface of the earth. Beyond it, the
airless vacuum of space begins.
Oxygen is made up of two oxygen atoms that are bonded together. In the
periodic table it is represented by O2.
Like oxygen, ozone is a gas that is made up of oxygen atoms. However,
a molecule of ozone is made up of three atoms of oxygen bonded together,
therefore, O3, represents ozone. The ozone makes up only .01% of the atmosphere.
Furthermore, 90% of the ozone is found in the stratosphere. It is concentrated
in a layer between 7 and 22 miles above the earth's surface.
The massive depth of the ozone in the stratosphere would lead you to
believe that it is very thick, it is not. If it were condensed, the ozone
layer would only be a few millimeters thick (Rowland and Molina 1994. p.23).
The ozone is made in the stratosphere. It is continuously being formed,
broken down, and reformed, over and over again. Furthermore, the three key
elements of the cycle are: oxygen, ozone, and the energy from the sun.
The ultimate source of energy for our planet is the sun. This energy
travels through space in the form of Electromagnetic Radiation. Furthermore,
this electromagnetic radiation is often referred to as waves and their length,
therefore, wavelengths. The sun has a wide range of wavelengths. This range is
known as the Electromagnetic Spectrum. In this spectrum there is Gamma,
Ultraviolet, Visible, Infrared, and Radio waves.
It is the ultraviolet (UV) radiation coming from the sun that drives the
ozone cycle in the stratosphere. When a oxygen molecule is hit by a high-energy
UV ray, the O2 molecule absorbs the ray's energy. As a result, the bond holding
the oxygen molecule together breaks. This break separates the molecule, O2=O+O.
These separate molecules quickly join with nearby oxygen molecules to form a
ozone molecule, O3=O2+O. Simultaneously, ozone molecules are being hit, they
absorb the ray's energy and break apart, leaving behind an oxygen molecule and a
single oxygen molecule, O3>O2-O. At this time, the entire process repeats
itself making new molecules that are separated which combine to make new
molecules, over and again (Rowland and Molin 1991 p. 42).
As a result of this cycle, about the same amount of ozone is produced as
is broken down in the stratosphere. Therefore, the amount of ozone stays the
same under normal circumstances (Rowland and Molina 1991 p.43).
A constant and stable ozone layer are important for life on earth
because the high-energy UV rays that are absorbed in the ozone layer are
extremely dangerous. These rays can kill some things while seriously damaging
others. For example, some bacteria exposed to UV rays will die. Plants, on
land and in oceans, can be seriously damaged or even destroyed by UV rays. When
humans are exposed to the powerful rays, their skin can burn, damage to the eyes
, and permanent changes in cells that can lead to cancer and other problems can
occur. By absorbing the UV rays, the ozone molecules in the ozone layer form a
shield that protects life on earth from the dangerous and even deadly UV rays.
Cfcs