The ozone layer

By Madeleine Murtagh

The ozone layer

The ozone layer is a layer of gas which is located in the stratosphere several miles above the Earth's surface. It is made up of ozone (a gas), 78% nitrogen, 21% oxygen, and argon.

The ozone layer protects us from the sun's dangerous ultra-violet rays. When the ultra-violet light hits oxygen molecules in the stratosphere (the layer in the atmosphere directly above the one we breathe in), it splits them into two oxygen atoms. When each of these atoms hits another oxygen molecule, it combines with the molecule and makes ozone. The UV light also breaks the ozone into an oxygen molecule and an oxygen atom. This is called the ozone-oxygen cycle and it protects the Earth by converting UV radiation to heat.

The ozone layer is being destroyed by many different types of air pollution. Probably the worst air pollution is from aerosol cans.

Common misconceptions about the ozone layer:

  1. CFC's (Chlorofluorocarbons) are heavier than air, so they can't reach the ozone layer.
  2. Volcanoes are causing ozone layer depletion
  3. Ozone layer depletion occurs only in Antarctica.
  4. No link exists between ozone layer depletion and higher UV levels.