The stratosphere is the layer
of the atmosphere from 10 to 30 miles above sea level.

 “The ozone layer” refers to
the ozone within stratosphere, where over 90% of the earth’s ozone
resides. The ozone layer absorbs 97-99% of the sun’s high frequency
ultraviolet light , light which is potentially damaging to life on
earth.

 In the absence of this
gaseous shield in the stratosphere, the harmful radiation has a perfect
portal through which to strike Earth. 

The amounts of “good” and
“bad” ozone in the atmosphere depend on a balance between processes that
create ozone and those that destroy it. An upset in the ozone balance
can have serious consequences for life on Earth. Scientists are finding
evidence that changes are occurring in ozone levels—the “bad” ozone is
increasing in the air we breathe, and the “good” ozone is decreasing in
our protective ozone shield.

 

NASA GSFC Graphic


Good Ozone.
Ozone occurs naturally in the Earth’s upper atmosphere—10 to 30
miles above the Earth’s surface—where it forms a protective layer that shields
us from the sun’s harmful ultraviolet rays. This beneficial ozone is gradually
being destroyed by manmade chemicals. An area where ozone has been significantly
depleted—for example, over the North or South pole—is sometimes called a “hole
in the ozone.”