The ozone layer is a deep layer located in the stratosphere that shields the Earth from harmful ultraviolet radiation from the sun. It contains 90% of the ozone in the atmosphere, residing 10-30 miles above the surface. The ozone layer plays a beneficial role by absorbing most UV-B radiation, allowing life on Earth to thrive. However, depletion of the ozone layer from CFC emissions and other chemicals has increased UV levels at the surface with harmful effects on humans, animals and plants. International agreements like the Montreal Protocol have aimed to reduce ozone depleting chemicals but more efforts are needed to balance natural ozone production and prevent further depletion.

1. The Ozone Layer
Nataly Quintanilla

2. What is the Ozone Layer?
• The Atmosphere is divided into different
layer.
• The ozone layer is a deep layer in the
stratosphere, encircling the Earth.
• The layer shields the entire Earth from
much of the harmful ultraviolet radiation
that comes from the sun.

3. Where is the Ozone Layer happening?
• Ozone is mainly found in two regions
of the Earth's atmosphere.
• Most ozone (about 90%) resides in a
layer that begins between 6 and 10
miles (10 and 17 kilometers) above the
Earth's surface and extends up to
about 30 miles (50 kilometers).
• This region of the atmosphere is called
the stratosphere.
• The ozone in this region is commonly
known as the ozone layer.
• The remaining ozone is in the lower
region of the atmosphere, which is
commonly called the troposphere.

4. How does it affect life on Earth? Or how is life
on Earth affected by it?
• Stratospheric ozone plays a beneficial role by absorbing most of
the biologically damaging ultraviolet sunlight (called UV-B),
allowing only a small amount to reach the Earth's surface.
• The absorption of ultraviolet radiation by ozone creates a source
of heat, which actually forms the stratosphere itself (a region in
which the temperature rises as one goes to higher altitudes).

5. Cont…
• Many experimental studies of plants
and animals and clinical studies of
humans have shown the harmful
effects of excessive exposure to UV-B
radiation.
• Without the filtering action of the
ozone layer, more of the Sun's UV-B
radiation would penetrate the
atmosphere and would reach the
Earth's surface.

6. Are there problems with the Ozone Layer?
• https://www.youtube.com/watch?v=XSLjApQGy5s

7. Are there problems with the Ozone Layer?
• At the Earth's surface, ozone comes into direct
contact with life-forms and displays its destructive
side.
• Because ozone reacts strongly with other
molecules, high levels of ozone are toxic to living
systems. Several studies have documented the
harmful effects of ozone on crop production,
forest growth, and human health.
• The substantial negative effects of surface-level
tropospheric ozone from this direct toxicity
contrast with the benefits of the additional
filtering of UV-B radiation that it provides
• . Depletion of the ozone layer has consequences
on humans, animals and plants. This typically
results from higher UV levels reaching us on
earth.
• Ozone layer depletion, is simply the wearing out
(reduction) of the amount of ozone in the
stratosphere.
• Unlike pollution, which has many types and
causes, Ozone depletion has been pinned down to
one major human activity. Depletion begins when
ultra violet radiation from the sun breaks up these
CFCs (chlorofluorocarbons).

8. What are some solutions?
• The only way is to remove the excess chlorine and
bromine from the stratosphere. And the only way
to do that is to stop making CFCs
(chlorofluorocarbons) and several other chemicals.
• This is why in the 1990s a meeting of the worlds
big nations met and agreed to reduce the usage of
CFCs and also encouraged other nations to do the
same. That was decided in the Montreal Protocol.
• This is not enough, but at least it was a good
starting point.
• Ozone is a natural gas and is naturally replenished
over time. This means if we can do something to
balance the natural production with its depletion,
there should not be a problem. Other way to
prevent ozone depletion:
1. Limit private vehicle driving
2. Use eco-friendly household cleaning products
3. Avoid using pesticides
4. Developing stringent regulations for rocket
launches
5. Banning the use of dangerous nitrous oxide