5. • The composition of gases in the
atmosphere and find out how
much ozone is present in air
comparatively, very little
amount of ozone is present in
the atmosphere. It is from about
18 to 55km above the earth’s
surface in the stratosphere.
6. Ozone layer Depletion
• Ozone is a deep blue gas present in
Stratosphere.
• It acts as a protective shield above
the earth.
• It absorbs harmful ultra-violet
radiation and prevents it from
reaching the earth’s surface.
• The thickness of ozone layer is
decreasing every year due to action
of green house effect.
7. • Thickness of ozone layer is more at
poles than at the equator.
• This decrease in thickness of ozone
layer is know as ozone layer
depletion or ozone hole.
• The ozone hole was first discovered
in 1985 over Antartica.
• It is more during spring time.
8. Problems caused by the
ozone depletion
• Changes in climate.
• Destruction to agriculture and
forests.
• Diseases like cataract and
blindness to eyes.
• Increase in incidence of skin
cancer.
