the Earth's atmosphere is what makes
life on Earth possible this atmosphere
protects us from harmful radiations of
the Sun and helps maintain the earth's
temperature by trapping some of the heat
that enters the atmosphere
the Earth's atmosphere is divided into
five layers depending upon the
temperature
the second layer known as stratosphere
holds a very important shield that
protects us from the sun's harmful
ultraviolet radiation and only lets in
the good rays this important shield is
known as the ozone layer
ozone is a gas with three atoms of
oxygen in a molecule and the formula is
oh three
the highest concentration of the ozone
gas is found in the stratosphere but its
amount is still less compared to the
other gases present in the stratosphere
despite its small amount the ozone layer
performs a very important function it
blocks the harmful ultraviolet
radiations of the Sun from reaching the
Earth's surface
the ultraviolet radiations of the Sun
can be very harmful for us it can cause
skin cancer blindness a weak immune
system and many other diseases the ozone
layer protects us from these harmful
ultraviolet rays by absorbing about 98%
of them but due to human activities this
protective layer is in danger in the
1980s scientists discovered that the
amount of ozone gas in the Earth's
atmosphere had decreased it was also
reported that 70% of the ozone layer was
reduced above Antarctica
this reduction of the ozone layer was
referred to as ozone depletion or the
ozone hole
the depletion of the ozone layer is
mainly caused by chemicals such as
chlorofluorocarbons or CFCs
hydrofluorocarbons and other
ozone-depleting substances
these chemicals are mostly found in
sprays refrigerants used in air
conditioners and refrigerators and
plastic products chlorofluorocarbons are
molecules made up of chlorine
Florine
and carbon when a chlorofluorocarbon
molecule is released into the Earth's
atmosphere the ultraviolet rays of the
Sun cause it to break up and release a
chlorine atom the ozone molecule is
highly reactive as it reacts with a
chlorine atom it produces a single
oxygen molecule and chlorine monoxide
chlorine monoxide further reacts with
another ozone molecule to produce
another chlorine atom which further
reacts with more ozone molecules the
chlorine atom is highly reactive
this results in the thinning of the
ozone layer in the atmosphere
as a result the harmful ultraviolet rays
penetrate through the atmosphere and
reach the Earth's surface these harmful
rays may affect human health by causing
skin cancer blindness and a weak immune
system these rays also affect plant
growth and ocean life
thus disturbing the entire ecosystem in
2016 it was reported that the amount of
chlorine and other ozone depleting
substances and the atmosphere had been
reduced and the ozone hole was gradually
healing
it is estimated that if we continue to
take measures to heal the ozone layer by
prohibiting the use of ozone depleting
substances the level of ozone will
return to the pre 1980s levels by 2075
let's summarize what we have learned
today the ozone layer is present in the
stratosphere the second layer of the
Earth's atmosphere the ozone layer
absorbs harmful ultraviolet rays of the
Sun and prevents them from reaching the
Earth's surface
the ultraviolet radiations of the Sun
can cause skin cancer blindness and
other harmful diseases it can also
affect the growth of plants
chlorofluorocarbons hydrofluorocarbons
and other ozone-depleting substances
from refrigerants sprays and plastic
materials react with the ozone molecules
in the stratosphere this results in the
depletion of the ozone layer
the use of ozone depleting substances
should be banned in order to prevent
those on their from disappearing
completely