Introduction to Ozone Depletion
Ozone is both beneficial and harmful to us. Near the ground, ozone forming as a result of
chemical reactions involving traffic pollution and sunlight may cause a number of
respiratory problems, particularly for young children.
However, high up in the atmosphere in a region known as the stratosphere,
ozone filters out incoming radiation from the Sun in the cell-damaging ultraviolet (UV)
part of the spectrum. Without this ozone layer, life on earth would not have evolved in
the way it has.
The stratosphere is the second major layer of the atmosphere and
lies above the troposphere, the lowest layer. It occupies the
region of atmosphere from about 12 to 50 km above the Earth's surface,
although its lower boundary tends to be higher nearer the equator
and lower nearer the poles.
Concentrations of ozone in the stratosphere fluctuate naturally in response to variations
in weather conditions and amounts of energy being released from the Sun,
and to major volcanic eruptions.
Nevertheless, during the 1970s it was realised that man-made emissions of CFCs and
other chemicals used in refrigeration, aerosols and cleansing agents may cause
a significant destruction of ozone in the stratosphere, thereby letting through
more of the harmful ultraviolet radiation.
Then in 1985 evidence of a large "ozone hole" was discovered above the continent of
Antarctica during the springtime. This has reappeared annually, generally growing larger
and deeper each year. More recently, fears have emerged about significant ozone depletion
over the Arctic, closer to the more populous regions of the Northern Hemisphere.
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Twenty Questions and Answers about the Ozone layer
Ozone is regularly
monitored above the UK determine the level of ozone loss.
For more information visit the
Ozone Hole Tour Web site