Ozone Layer- Overview, Effects on Earth and World Ozone Day

The ozone layer is a region of the Earth’s atmosphere with very high quantities of ozone gas, an inorganic molecule with the chemical formula O3. Ozone is a pallid blue gas with a strong odor. The Ozone Layer is significant for both the UPSC Prelims and GS Paper 3 of the UPSC Mains curriculum. In this article, we will provide you with all features and necessary information on the Ozone Layer, its types, and the depletion of the Ozone Layer. Study major topics of the environment from the perspective of UPSC Exams.

What is an Ozone Layer?

• The ozone layer is a thin layer of the Earth’s atmosphere that absorbs nearly all of the sun’s ultraviolet energy.
• The term “ozone hole” refers to areas of ozone layer degradation. This is incorrect. Damage to the ozone layer is more akin to a very thin patch than a hole.
• The ozone layer shields the Earth from the majority of UVB rays from the sun.
• Even in the absence of ozonle depletion, it is critical to protect oneself from UVB rays by wearing hats, sunglasses, and sunscreen. However, as ozone depletion progresses, these safeguards will become more critical.

Who Discovered Ozone Layer?

• Schönbein discovered Ozone Layer in the atmosphere in 1867, and Andrews confirmed it a year later in 1868.
• Solar spectrum measurements were then used to determine the quantity of ozone in the passage between the sun and the earth.

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Where is the Ozone Layer Found?

• Ozone is typically present in two areas of the atmosphere. The troposphere, the area nearest to Earth, contains around 10% of the atmospheric ozone.
• The remaining ozone (approximately 90%) is found in the stratosphere between the tropopause and 50 kilometers altitude.
• The “ozone layer” refers to the high concentration of ozone in the stratosphere.

Types of Ozone Layer

• There are two kinds of ozone: “good” and “bad” ozone.
• The troposphere contains ozone, which is hazardous to life (causing breathing problems in people) and vegetation (damages crops and plants.)
• The bad ozone is made up of urban pollution. The stratosphere, which also houses the ozone layer, has good ozone.

Stratospheric Ozone

• The “good” ozone, also known as stratospheric ozone, is found naturally in the high atmosphere.
• This ozone creates a barrier that protects humans from the sun’s damaging ultraviolet (UV) radiation.
• UV radiation can be caused by the sun’s UV rays. UV radiation may cause skin cancer, skin damage such as premature ageing, cataracts and other eye damage, and immunological suppression.

Ground-level Ozone

• Human activity is the cause of “bad” ozone, also known as ground-level ozone.
• This hazardous air pollutant harms humans and the environment and is the primary component of “smog.”

Ozone Layer Hole

• The ozone hole isn’t truly a hole; it refers to an area in the stratosphere where ozone concentrations drop to dangerously low levels during certain months.
• The most often discussed ‘ozone holes’ are the depletions over Antarctica, which emerge each year in the months of September, October, and November as a result of a series of specific climatic and chemical circumstances that arise around the South Pole.

World Ozone Day

• The United Nations General Assembly declared September 16th to be the International Day for the Preservation of the Ozone Layer in 1994, marking the date of the signing of the Montreal Protocol in 1987.

Ozone Layer Important Facts

• Christian Friedrich Schönbein, a German-Swiss scientist, developed and isolated ozone in 1839.
• Ozone is a light blue gas with a strong unpleasant odor.
• Schönbein called it ozone after the Greek term ozein, which means “to smell.”
• The refreshing scent of seashore air, which many people mistake for ozone, is really dimethyl sulphide, which is created by decomposing seaweed.
• Ozone near the ground may be dangerous. It is a component of smog and can cause breathing problems and chest discomfort.
• Car and vehicle exhausts, as well as natural gas production, emit harmful ground-level ozone.
• Good ozone is ozone in the ozone layer of the atmosphere, which is 10-20 miles high and shields humans from the Sun’s damaging UVB rays.
• In 1989, the Montreal Protocol was signed to prohibit ozone-depleting compounds such as CFCs.

How Ozone Layer is Formed?

• Chemical reactions of pollutants in the presence of sunlight produce ground-level ozone. Pollutants produced by these chemical reactions include nitrogen oxides (NOx) and volatile organic compounds (VOCs).
• Pollutants can be emitted by cars, power plants, industrial boilers, refineries, chemical plants, and other sources. The polar vortex at the North Pole expands during the winter, sending cold air southward.
• An ozone hole is a thinning of the ozone layer that is exacerbated by colder temperatures.
• As temperatures rise in the stratosphere, ozone depletion slows and the polar vortex weakens and breaks down.

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What is Ozone Layer Depletion?

• Human activities cause the release of chemicals containing chlorine and bromine atoms into the atmosphere. These chemicals react with certain weather conditions to cause reactions in the Ozone Layer, resulting in the destruction of ozone molecules.
• The Ozone Layer is depleted all over the world, but the severe depletion of the Ozone Layer over Antarctica is known as the ‘Ozone Hole.’

Causes of Ozone Layer Depletion

• Ozone can be destroyed faster than it can be created. When certain compounds are exposed to intense UV light in the stratosphere, they emit chlorine or bromine.
• Ozone-depleting substances (ODS) are chemicals that, if allowed to escape, harm the upper atmosphere’s ozone layer. Because some ODS have global warming potential, they contribute to climate change. The majority of ODS are now prohibited.
• The following is a list of some of the most common ozone-depleting compounds and the sources from which they are released:

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Chlorofluorocarbons

• Chlorofluorocarbons are compounds composed of chlorine, fluorine, and carbon. They are emitted into the environment by discarded refrigerators, aerosols, solvents, and other substances.
• When CFC molecules are exposed to UV radiation, they break up, releasing chlorine atoms. This free chlorine atom depletes Ozone by reacting with it.

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Nitrogenous Compounds

• Nitrogenous compounds such as NO2, NO, and N2O are to blame for ozone depletion.
• Nitrogen Oxides are primarily produced by thermonuclear weapon explosions, agricultural fertilizers, and industrial pollution.
• Hydrobromofluorocarbons (HBFCs) is bromine compounds that are utilized in fire extinguishers.
• Each bromine atom kills a hundred times the number of ozone molecules as a chlorine atom.

Fossil fuels

• The ozone layer is being destroyed by the use of fossil fuels. Fossil fuels are used in automobiles, factories, and to generate electricity.
• These fuels are known as fossil fuels because they were formed from the organic remains of prehistoric plants and animals.

Effects of Ozone Layer Depletion

• The ozone layer’s depletion is hazardous to human health, animals, the environment, and marine life.
• Ozone layer depletion is the thinning of the upper atmosphere’s ozone layer. This occurs when chlorine and bromine atoms in the atmosphere come into touch with ozone and destroy it.
• One chlorine atom can destroy 100,000 ozone molecules. It is destroyed faster than it is formed.
• Reduced Ozone levels imply higher penetration of solar UV-B radiation to the Earth’s surface. It is extremely harmful to human health, animals, plants, bacteria, and air quality.

Effects on Health

Studies show that an increase in UV-B rays increases the risk of skin cancer, and plays a major role in the development of malignant melanoma, sunburns, rapid aging, eye cataracts, blindness, and a weakened immune system. Direct ultraviolet radiation exposure causes skin and eye cancer in animals.

The Impact on Marine Life

• UV-B rays is harmful to plants and crops. It may result in reduced plant growth, smaller leaf size, blooming and photosynthesis in plants, and lower agricultural quality for people.
• Plant productivity declines, in turn, have an impact on soil erosion and the carbon cycle.
• UV-B rays have a significant impact on planktons and zooplankton. If the plankton population drops, it will most likely have far-reaching consequences for all marine creatures in the bottom food chain.

Human and Animal Health Consequences

• People become more vulnerable as the incidence of morbidity from eye diseases, skin cancer, and infectious diseases rises.
• UV B radiation is the primary risk factor for the development of Non-Melanoma skin cancer in people with fair skin.

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Effects on Plants

• UV-B light has an impact on plant psychological processes.
• The way different species react to UV-B differs enormously. As a result, more UV-B tolerant species must be used in agriculture.
• It changes the composition of species in forests and grasslands.
• UV-B radiation causes various indirect changes, including plant shape, biomass allocation, and the timing of development phases.

Effects on Aquatic Ecosystems

• More UV-B radiation exposure has affected phytoplankton motility, resulting in lower survival rates for these organisms.
• UV-B radiation has been shown to cause developmental damage in fish, crabs, amphibians, and other animals. The more serious effect is a reduction in reproductive capacity.

Effects on Air Quality

• Higher photodissociation rates of gases that influence the chemical reactivity of the Troposphere to arise from the reduction of Ozone in the upper layers of the atmosphere and the direct increase of UV-B radiation entering to the lower atmosphere.
• The products of these interactions are recognized to be harmful to human health, plants, and outdoor objects.
• Higher tropospheric reactivity will result in increased particle formation due to oxidation and sulfur nucleation from both anthropogenic and natural sources.

Effects on Materials

• UV radiation affects materials such as polymers, naturally occurring biopolymers, and several other commercially important materials.
• Increased solar UV-B concentration owing to partial ozone depletion increases photodegradation of certain materials, limiting their outdoor life.

Montreal Protocol on Ozone Layer depletion The Montreal Protocol is a multilateral environmental treaty that governs the manufacture and use of ozone-depleting compounds (ODS). It became law on September 15, 1987. The Montreal Protocol Parties agreed to phase down hydrofluorocarbons at their 28th Meeting of the Parties on October 15, 2016, in Kigali, Rwanda. Countries decided to add HFCs to the list of prohibited substances and set a timetable for reducing them by 80-85 percent by the late 2040s.

Importance of Ozone Layer

• The ozone layer shields the Earth from the majority of UVB rays from the sun. Even in the absence of ozone depletion, it is critical to protect oneself from UVB rays by wearing hats, sunglasses, and sunscreen.
• By absorbing damaging UV radiation, the ozone layer supports life on Earth. The upper atmosphere becomes cooler as the layer thins, causing winds in the stratosphere and troposphere below to change, displacing jet streams and storm tracks.
• Ozone shields the Earth from harmful ultraviolet (UV) rays emitted by the sun. Without the Ozone layer in the atmosphere, life on Earth would be exceedingly impossible.
• Plants and planktons, which provide sustenance for the majority of ocean life, cannot survive and grow in high ultraviolet exposure.
• Humans would be more vulnerable to skin cancer, cataracts, and immune system impairment if the Ozone Layer protection was weakened.
• The relevance of ozone is defined by the fact that it shields the earth from the sun’s harmful UV rays.
• The ozone layer is present in the upper stratosphere and protects the earth from the sun’s harmful ultraviolet rays.

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What Are Ways To Protect Ozone Layers?

• We should swap environmentally friendly things for that. Maintain air conditioners since CFCs seep into the atmosphere when they fail.
• Avoid consuming ozone-depleting gases because of their composition and manufacturing process.
• Instead of utilizing chemicals, cease using pesticides and turn to natural pest control solutions.
•  Cars emit a considerable amount of greenhouse gases, which contribute to global warming and ozone depletion.
• Vehicle use should thus be curtailed to the greatest extent practicable. Many cleaning solutions contain chemicals that deplete the ozone layer.
• Reduce your usage of automobiles and avoid using cleaning solutions that are damaging to the environment and people.
• Usage natural and local items and limit the use of machines that contain chlorofluorocarbons, such as refrigerators and air conditioners.

Conclusion

Ozone abundances in the stratosphere and troposphere are determined by the balance between chemical reactions that make and destroy ozone. The number of reactive gases and how the pace or efficacy of the different reactions vary with solar intensity, position in the atmosphere, temperature, and other variables influence the balance. Shortness of breath, wheezing, and coughing can occur in those who have respiratory disorders such as asthma or who are active outside on days when ozone levels are high. We can all do our part to protect ourselves and limit the harmful impacts of this pollution on our health and the environment.

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