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Importance of the ozone layer:
Ozone is concentrated in the lower stratosphere between 15 and 30 km above the earth’s surface – the so-called ‘ozone layer’. Ozone can be produced by numerous chemical reactions, but the main mechanism in the atmosphere for its production and removal is absorption of ultra-violet (UV) radiant energy from the sun.
Ozone is produced when O2 absorbs UV radiation at wavelengths of less than 242 nanometers, and is removed by photo-dissociation from sunlight for wavelengths greater than 290nm. O3 is also the major absorber of UV sunlight between 200 and 330nm. The combination of these processes is effective in maintaining a relatively constant amount of ozone in the layer, and in absorbing 90% of UV sunlight.
UV is linked to the formation of skin cancer and genetic damage. Increased levels of UV are known to have adverse effects on animal immune systems, aquatic organisms at the bottom of the food chain, terrestrial plants and food crops.
The maintenance of enough stratospheric ozone to absorb harmful UV sunlight is therefore vitally important to all life forms on earth.
Depletion of the ozone layer:
The ozone layer protects the Earth from the ultraviolet rays sent down by the sun. If the ozone layer is depleted by human action, the effects on the planet could be catastrophic.Ozone is present in the stratosphere.
The stratosphere reaches 30 miles above the Earth, and at the very top it contains ozone. The suns rays are absorbed by the ozone in the stratosphere and thus do not reach the Earth.Ozone is a bluish gas that is formed by three atoms of oxygen.
The form of oxygen that humans breathe in consists of two oxygen atoms, O2. When found on the surface of the planet, ozone is considered a dangerous pollutant and is one substance responsible for producing the greenhouse effect.The highest regions of the stratosphere contain about 90% of all ozone.
In recent years, the ozone layer has been the subject of much discussion. And rightly so, because the ozone layer protects both plant and animal life on the planet.The fact that the ozone layer was being depleted was discovered in the mid-1980s.
The main cause of this is the release of CFCs, chlorofluorocarbons.Antarctica was an early victim of ozone destruction. A massive hole in the ozone layer right above Antarctica now threatens not only that continent, but many others that could be the victims of Antarctica's melting icecaps.
In the future, the ozone problem will have to be solved so that the protective layer can be conserved.
Ozone depletion animation:
Ozone Depletion - Video:
Ozone Depletion - Presentation: