Is The Stratospheric Ozone Layer Recovering?
The stratospheric ozone layer shields life on Earth from harmful solar ultraviolet (UV) radiation. Research has clearly shown that excess exposure to UV radiation is harmful to agriculture and causes skin cancer and eye problems. Excess UV radiation may suppress the human immune system. Ozone is formed naturally in the stratosphere through break-up of oxygen molecules (O2) by solar UV radiation. Individual oxygen atoms can combine with O2 molecules to form ozone molecules (O3). Ozone is destroyed when an ozone molecule combines with an oxygen atom to form two oxygen molecules, or through catalytic cycles involving hydrogen, nitrogen, chlorine or bromine containing species. The atmosphere maintains a natural balance between ozone formation and destruction. The natural balance of chemicals in the stratosphere has changed, particularly due to the presence of man-made chlorofluorocarbons (CFCs). CFCs are non-reactive and accumulate in the atmosphere. They are destroyed in the high stratosp
