The ozone layer

Ozone: found in the upper atmosphere

Job: absorbs ultraviolet light from the sun's rays and stops much of it from reaching the earth's surface

Main factor affecting the ozone layer: it is now known that CFC's, chemicals found in refrigerators and aerosol cans, are causing the reduced thickness of the ozone layer.

Effects of this: this causes more ultraviolet light to reach the earth's surface, causing skin cancer to many humans.