The earth’s ozone layer provides protection to all the living species on earth by absorbing the UV radiations and preventing them from reaching us. The term ‘ozone depletion’ is used to describe the process when this protective layer is damaged or is destroyed. There are various factors which contribute to depleting the ozone layer such as industrial activities, exhaust of chlorofluorocarbons, etc. In today’s article we will try to understand what exactly is ozone layer depletion and see how it affects life on earth in a negative manner.
What is Ozone Layer Depletion?
The ozone layer is a deep layer in Earth’s atmosphere called the stratosphere. It extends from about 6 to 30 miles (10 to 50 kilometers) above Earth’s surface. In this region, ozone molecules are clustered in high concentrations — roughly 10 to 100 parts per million. The cluster of ozone molecules is commonly referred to as the “ozone layer.”
What Is Ozone Layer Depletion?
Ozone layer depletion occurs when the natural balance between the production and destruction of stratospheric ozone is tipped in favor of destruction. This can occur through chemical reactions involving industrial chemicals called chlorofluorocarbons and bromine-containing substances called halons.
How does the ozone layer form and function?
The ozone layer is a deep layer in the stratosphere, encircling the Earth, that has large concentrations of ozone (O3). It resides at an altitude of 15 to 30 kilometers (9 to 18 miles) above the Earth’s surface, depending on latitude. The ozone layer is mainly found in the lower portion of the stratosphere, from approximately 20 to 30 kilometers (12 to 19 miles) above Earth, although its thickness varies seasonally and geographically.
Why do we need the ozone layer?
The ozone layer absorbs 97-99% of the sun’s high frequency ultraviolet light, which is potentially damaging to life on earth. This protection is particularly important in relation to UVB as it causes sunburn and skin cancers. We only need a little exposure to UVB for our bodies to produce Vitamin D, so we don’t need to be exposed to it all of the time.
What happens if we lose the ozone layer?
Without the ozone layer, much more UV would reach the earth’s surface, and there would be a huge increase in skin cancers, cataracts and immune system damage.
What caused the hole in the ozone layer?
In 1974 scientists Sherwood Rowland and Mario Molina identified chlorofluorocarbons as gases that could destroy ozone molecules in the stratosphere. The main source was from aerosol sprays containing chlorofluorocarbons (CFCs). In 1985, British scientists found that an area of unusually low ozone over Antarctica varied each year with the seasons. The finding was confirmed by US satellite data and by November 1985, scientists had identified a large ‘hole’ in the ozone layer above Antarctica.
Ozone Layer Depletion Causes
The three main gases that contribute to the destruction of the ozone layer are carbon tetrachloride, halon, and methyl chloroform. These gases are used as solvents and degreasing agents, in medicine and fire extinguishers, in pesticides and refrigerants.
Chlorofluorocarbons (CFCs) are compounds containing chlorine, fluorine and carbon that have been used extensively as refrigerants, propellants (in aerosol sprays), and solvents. When these substances reach the stratosphere, they undergo a series of reactions that break down ozone molecules.
Carbon tetrachloride was widely used as a solvent for cleaning metals or degreasing surfaces and in pesticides; but it has been banned in most countries since 2010 due to its effect on the ozone layer.
Effects on Plants
Ultraviolet radiation can damage plant DNA as well as chlorophyll and carotenoid molecules that help plants capture solar energy. Some plants are especially vulnerable to ultraviolet radiation because they grow close to Earth’s poles, where the UV intensity is higher due to ozone depletion. For example, Antarctic macroalgae experienced a decline in growth during a period of ozone depletion, while some Arctic plants exhibited signs of DNA damage as a result of exposure to UV light.
Effects on Animals
The depletion of the ozone layer increases the amount of UV radiation that reaches Earth’s surface. This can cause problems for some animal species because their white fur or feathers can reflect UV light rather than absorb it, resulting in burned patches on their skin. For example, albino seals exhibit signs of skin cancer due to exposure to increased levels of UV radiation. Depletion of the ozone layer
Man-made chemicals responsible for ozone depletion
The main cause of ozone depletion and the ozone hole is manufactured chemicals, especially chlorofluorocarbons (CFCs). CFCs and other ozone-depleting substances (ODS) are mostly used as
How Can We Prevent Ozone Layer Depletion?
Ozone layer depletion can have dangerous effects on our health and environment. Therefore, it is necessary to take preventive measures to reduce its harmful effects. Some of these are:
Use of non-CFC based products
Use energy efficient appliances
Reduce emission of carbon dioxide (CO2)
Increase awareness about ozone layer depletion