OZONE LAYER.• The ozone layer is a layer in Earth's atmosphere which contains

relatively high concentrations of ozone (O3).

• This layer absorbs 97–99% of the Sun's high frequency ultraviolet light, which potentially damages the life forms on Earth.

• It is mainly located in the lower portion of the stratosphere from approximately 20 to 30 kilometres above Earth.

• Created by ultraviolet light striking oxygen atoms (O2), splitting them into individual oxygen atoms (atomic oxygen);

• The atomic oxygen then combines with unbroken O2 to create ozone, O3

OZONE LAYER DEPLETION.

• The ozone layer can be depleted by free radicals

hydroxyl (OH-), chlorine (Cl-), bromine (Br-). chlorofluorocarbons (CFCs) and

bromofluorocarbons

EFFECTS OF OZONE DEPLETION.• More ultraviolet light from the sun can reach the Earth. • UV increase can cause skin cancer, cataracts

(snowblindness or photokeratitis), and suppression of the human immune system.

• In addition to cancer, some research shows that a decreased ozone layer will increase rates of malaria and other infectious diseases.

• Oceans will be affected as well. The most basic microscopic organisms such as plankton may not be able to survive.

• Climate changes. Melting of glaziers (rising sea levels)