Question

Why is the depletion of the ozone layer a matter of concern for us? What steps have been taken to minimize it?

Answer 1

Hint: Earth’s atmosphere consists of several layers, among which the stratosphere is the one where ozone concentration is maximum. The ozone layer prevents the ultraviolet rays from the sun from reaching the earth’s surface. These ${\text{UV}}$ rays are harmful as they cause skin cancers.

Complete step by step answer:
The Ozone layer is located in the stratosphere about \[{\text{15 to 30 kms}}\] above the earth’s surface. Ozone layer is composed of ozone molecules $\left( {{O_3}} \right)$ that constantly form and destroy over time but there are certain chemicals mainly chlorine and bromine that can degrade them. Antarctic ozone holes are an example of ozone layer depletion.
Step (1): Importance of the Ozone layer:
Ozone layer absorbs the portion of ultraviolet light called the${\text{UVB}}$, which is found to cause harmful effects such as skin cancers, immune deficiency and cataracts. This is also hazardous to the marine ecosystem. More levels of ${\text{UVB}}$ can damage the crops which will reduce agricultural activities. So, Ozone layer depletion is a matter of concern for us.
Step (2): Steps to minimize ozone layer depletion:
The chemicals Chlorine and Bromine which contribute to ozone layer depletion come from ${\text{CFCs}}$ (Chlorofluorocarbon), ${\text{HCFCs}}$ (Hydrochlorofluorocarbons, carbon tetrachloride, methyl chloroform, halons and methyl bromide. These chemicals are mainly released by chemical industries, refrigerators, fire suppressors, etc. To minimize the use of such chemicals some protocols have been taken under the Montreal Protocol in the late${\text{1980s}}$. It is advised to minimize the use of refrigerators in home and air conditioners electrical appliances.
So, these are the steps taken to minimize ozone layer depletion.

Note:
Mechanism of ozone layer depletion UV radiation first hits the ${\text{CFC}}$ molecule to break Chlorine from it. This free chlorine then hits the ozone molecule, and takes one oxygen atom to form chlorine monoxide and leaves one molecule of oxygen. Free oxygen atom hits the chlorine monoxide molecule to form oxygen molecule and free chlorine atom. This chlorine atom then hits another ozone molecule and the process goes on.