What is the ozone layer depletion?
The ozone layer depletion shows the reduction in the concentrations of ozone molecules present in the ozone layer. Or ozone layer depletion can also be described as a decrease in the thickness of the ozone layer.
For the first time in 1981, the ozone hole was detected in the upper atmosphere of Antarctica. After that scientist takes this phenomenon seriously and started searching for its cause. By 2005, the antarctic ozone hole had grown to 24 million sq km, equivalent to the area of North America. The ozone layer depletion has seen very much in very cold foggy areas.
The major reason for ozone layer depletion is the emission of the compound called chlorofluorocarbon(CFC). It is mostly emitted in gases form. In 1930, first time CFC gas was created to use in refrigerator as coolant. Other products like an air conditioner, fire extinguishers, and shaving creams also Emmit the CFC gas.
CFC is very light gas and raises to the top of the atmosphere where the ozone layer exists. The chlorine present in CFC compound reacts with the ozone gas and form the chlorine monoxide as well as release the oxygen. So, the more amount of CFC results in more degradation of ozone gas(O3). Due to this, the amount of ozone gas is decreased and the thickness or concentration of ozone reduced. As a result, more amount of ultraviolet radiation comes to the earth’s surface.
The halogen gases like Cl, Br, etc are responsible for the reduction of ozone. Other chemicals like hydrocarbon, Helon which is used in a fire extinguisher, etc are also responsible for ozone layer depletion.
Effects of ozone layer depletion
- The exposure of ultraviolet rays causes many types of skin cancer in humans. These include malignant melanoma, basal and squamous cell carcinoma.
- Direct exposure to UV rays can cause problems such as mist blindness and cataracts.
- White-skinned people have to suffer from rashes and other skin diseases due to the harmful effects of ultraviolet rays.
- If a pregnant woman comes in contact with ultraviolet rays, they have to face the harmful effects of irreparable pregnancy loss.
- Plant growth is directly affected by UV-B radiation. A special type of ultraviolet rays (UV-B) penetrates several kilometers into the ocean and harm marine life. Ultraviolet radiation has a profound impact on the lives such as Plant plankton and bacterioplankton affecting the food chain as well as the entire ecosystem.
Furthermore, ozone present in troposphere acts as a greenhouse gas, which causes global warming and climate change.
To solve the problem of the worldwide threat of the destruction of the ozone layer, a meeting of 47 nations was held in Montreal, Canada in September 1987 and an agreement called the Montreal Protocol was signed. The agreement called for stopping the use of ozone-depleting chemicals within a certain time.