Ozone Layer in Simple Terms
Ozone or trioxygen, is an inorganic molecule with the chemical formula O3. It is a pale blue gas with a distinctively pungent smell. It is an allotrope of oxygen that is much less stable than the diatomic allotrope O2, breaking down in the lower atmosphere to O2 (dioxygen). Ozone is formed from dioxygen by the action of ultraviolet (UV) light and electrical discharges within the Earth’s atmosphere.
The ozone layer is the common term for the high concentration of ozone that is found in the stratosphere around 15–30km above the earth’s surface. It covers the entire planet and protects life on earth by absorbing harmful ultraviolet-B (UV-B) radiation from the sun. The sun emits three different types of UV radiation: UVA, UVB, and UVC. … UVA rays, which account for 95 percent of radiation that reaches the earth’s surface, cause wrinkles, “sun spots,” and other types of premature aging. The stratospheric ozone layer is Earth’s “sunscreen” – protecting living things from too much ultraviolet radiation from the sun. The emission of ozone depleting substances has been damaging the ozone layer.
Ozone Layer Depletion –
Ozone layer depletion is the thinning of the ozone layer present in the upper atmosphere. This happens when the chlorine and bromine atoms in the atmosphere come in contact with ozone and destroy the ozone molecules. One chlorine can destroy 100,000 molecules of ozone. It is destroyed more quickly than it is created. Ozone depletion consists of two related events observed since the late 1970s: a steady lowering of about four percent in the total amount of ozone in Earth’s atmosphere, and a much larger springtime decrease in stratospheric ozone around Earth’s polar regions. The latter phenomenon is referred to as the ozone hole.
International Ozone Day –
In 1994, the United Nations General Assembly proclaimed 16 September the International Day for the Preservation of the Ozone Layer, commemorating the date of the signing, in 1987, of the Montreal Protocol on Substances that Deplete the Ozone Layer.
The theme for the celebration of 2020 World Ozone Day to be marked on 16th September is “Montreal Protocol – Keeping us, our food and vaccines cool“. This year’s World Ozone Day seeks to highlight, the Montreal Protocol does so much – such as slowing climate change and helping to boost energy efficiency in the cooling sector, which contributes to food security. The Protocol has been universally ratified by all 197 member countries of United Nations.
The Dobson Unit
The Dobson Unit (DU) is the unit of measure for total ozone. If you were to take all the ozone in a column of air stretching from the surface of the earth to space, and bring all that ozone to standard temperature (0 °Celsius) and pressure (1013.25 millibars, or one atmosphere, or “atm”), the column would be about 0.3 centimeters thick. Thus, the total ozone would be 0.3 atm-cm. To make the units easier to work with, the “Dobson Unit” is defined to be 0.001 atm-cm. Our 0.3 atm-cm would be 300 DU.
Effects Of Ozone Layer Depletion-
The depletion of the ozone layer has harmful effects on the environment. Let us see the major effects of ozone layer depletion on man and environment.
On Human Health-The humans will be directly exposed to the harmful ultraviolet radiations of the sun due to the depletion of the ozone layer. This might result in serious health issues among humans, such as skin diseases, cancer, sunburns, cataract, quick ageing and weak immune system.
On Animals-Direct exposure to ultraviolet radiations leads to skin and eye cancer in animals.
On Environment-Strong ultraviolet rays may lead to minimal growth, flowering and photosynthesis in plants. The forests also have to bear the harmful effects of the ultraviolet rays.
On Marine Life-Planktons are greatly affected by the exposure to harmful ultraviolet rays. These are higher in the aquatic food chain. If the planktons are destroyed, the organisms present in the food chain are also affected.
The Antarctic ozone hole — one of the deepest, largest gap in the ozone layer in the last 40 years — has closed, according to World Meteorological Organization (WMO) January 6, 2021.
Still we have to work for Ozone Layer –
The depletion of the ozone layer is a serious issue and various programmes have been launched by the government of various countries to prevent it. However, steps should be taken at the individual level as well to prevent the depletion of the ozone layer.
Following are some points that would help in preventing this problem at a global level:
Avoid the consumption of gases dangerous to the ozone layer-Due to their content or manufacturing process. Some of the most dangerous gases are CFCs (chlorofluorocarbons), halogenated hydrocarbon, methyl bromide and nitrous oxide.
Minimize the use of cars- The best transport option is urban, bicycle, or walking. If you use a car to a destination, try to carpool with others to decrease the use of cars in order to pollute less and save.
Do not use cleaning products that are harmful to the environment and to us-Many cleaning products contain solvents and substances corrosive, but you can replace these dangerous substances with non-toxic products such as vinegar or bicarbonate.
Buy local products- In this way, you not only get fresh products but you avoid consuming food that has travelled long distances. As the more distance travelled, the more nitrous oxide is produced due to the medium used to transport that product.
Maintain air conditioners- As their malfunctions cause CFC to escape into the atmosphere.
We have only One Home : The earth- SAVE IT
Dr. Neeraj Saxena– Director
Rakshpal Bahadur Management Institute, Bareilly