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I’m going to talk about the Depletion of Ozone Layer today along with its formation, the reason behind depletion, its Effects, and much more down here at Engineers Rail.
So have a seat and relax while I begin this brief and enjoyable journey with you.
So without further ado, let’s enter the mainstream.
Before going into the mainstream, Let’s first see the introductive definition and formation of the Ozone layer-
What is Ozone Layer?
The ozone layer, also called the ozonosphere, region of the upper atmosphere, is between roughly 15 and 35 km (9 and 22 miles) above Earth’s surface, containing relatively high concentrations of ozone molecules (03).
Approximately 90 percent of the atmosphere’s ozone occurs in the stratosphere, the region extending from 10-18 km (6-11 miles) to approximately 50 km (about 30 miles) above Earth’s surface.
In the stratosphere, the temperature of the atmosphere rises with increasing height, a phenomenon created by the absorption of solar radiation by the ozone layer.
The ozone layer effectively blocks almost all solar radiation of wavelengths less than 290 nanometres from reaching Earth’s surface, including certain types of ultraviolet (UV) and other forms of radiation that could injure or kill most living things.
Formation of Ozone Layer-
Ozone is a gas found in the atmosphere consisting of three oxygen atoms: O3. Ozone is formed in the atmosphere when energetic ultraviolet (UV) radiation dissociates molecules of oxygen into separate oxygen atoms.
Free oxygen atoms can recombine to form oxygen molecules but if a free oxygen atom collides with an oxygen molecule, it joins up, forming ozone.
Ozone molecules can also be decomposed by ultraviolet radiation into a free atom and an oxygen molecule. Ozone is thus continuously created and destroyed in the atmosphere by UV radiation coming from the sun.
This highly energetic UV radiation is called UVC (wavelength 280 nm) and is very harmful to human health.
UVC is fully absorbed in the atmosphere by oxygen and ozone molecules. Ozone also absorbs UVB radiation, which is less energetic (wavelength 280-325 nm) but also harmful, before it reaches the surface of the Earth.
In this creation/destruction process the amounts of ozone molecules created and destroyed are roughly equal, so the total amount of ozone in the atmosphere is nearly constant.
The absolute concentration of ozone in the atmosphere is very low, out of 10 million air molecules only 3 are ozone molecules.
Reason Behind the Ozone Layer Depletion-
There are various reasons or causes behind ozone depletion including-
- The main cause of the depletion of the Ozone layer is human activity mainly human-made chemicals that contain chlorine or bromine. These chemicals are known as ODS which is Ozone – Depleting Substances.
- Since the early 1970s ozone reduction in stratospheric ozone is observed and it was found more prominent in Polar Regions.
- It is found that one molecule of chlorine has the capability to break down thousands of ozone molecules. The chief ozone-depleting substances include chlorofluorocarbons (CFCs), carbon tetrachloride, hydrochlorofluorocarbons (HCFCs), and methyl chloroform. Halons, sometimes known as brominated fluorocarbons, also contribute mightily to ozone depletion. ODS substances have a lifetime of about 100 years.
- Oxygen molecules, abundant throughout the atmosphere, are split apart into individual atoms when energized by radiation from the sun. These atoms are free to collide with other O2 molecules to form ozone (O3). The particular configuration of the ozone molecules allows them to absorb the sun’s radiation in ultraviolet wavelengths that are harmful to life if they penetrate the earth’s surface.
- Below the ozone layer, too little solar radiation penetrates to allow appreciable amounts of ozone to form. Thus most of the world’s ozone is in a stratospheric layer bulging with ozone at latitudes from 10 to 35 kilometers. Closer to the ground, in the troposphere, ozone produced through a series of chemical reactions involving hydrocarbons and nitrogen oxide emissions from vehicles and industrial activity is an effective greenhouse gas.
- Thus, ozone plays two very different roles in global environmental change: one in the stratosphere as a shield against harmful ultraviolet radiation, and another nearer the ground in the troposphere as a greenhouse gas find a health hazard. The chlorine atoms can then engage with ozone in a catalytic reaction in which each chlorine fragment can destroy up to 100,000 ozone molecules before other chemical processes remove the chlorine from the atmosphere.
Effect of Ozone layer Depletion-
The effect of ozone layer depletion can be seen in several things, some of which are listed and described below-
- Effects on Human Health
- Effects on Plants
- Effects on Marine Ecosystems
- Effects on Biogeochemical Cycles
- Effects on Materials
1. Effects on Human Health-
Ozone layer depletion increases the amount of UVB that reaches the Earth’s surface. UVB causes non-melanoma skin cancer and plays a major role in malignant melanoma development.
Also, UVB has been linked to the development of cataracts, a clouding of the eye’s lens. Because all sunlight contains some UVB, even with normal stratospheric ozone levels, it is always important to protect your skin and eyes from the sun.
2. Effects on Plants-
UVB radiation affects the physiological and developmental processes of plants. Despite mechanisms to reduce or repair these effects and an ability to adapt to increased levels of UVB, plant growth can be directly affected by UVB radiation.
Indirect changes caused by UVB are equally important as the damaging effects of UVB. These changes can have important implications for plant competitive balance, herbivores, and plant diseases. and biogeochemical cycles.
3. Effects on Marine Ecosystem-
Phytoplankton form the foundation of aquatic food webs.
Phytoplankton productivity is limited to the euphotic zone, the upper layer of the water column in which there is sufficient sunlight to support net productivity.
Exposure to solar UVB radiation results in the orientation and motility of phytoplankton consequently reducing survival rates for these organisms.
UVB radiation has been found to cause damage to the early developmental stages of fish, shrimp, crabs, amphibians, and other marine animals.
The most severe effects are decreased reproductive capacity and impaired larval development.
Small increases in UVB exposure could result in population reductions for small marine organisms with implications for the whole marine food chain.
4. Effects on Biogeochemical Cycles-
Increases in UVB radiation could affect terrestrial and aquatic biogeochemical cycles, thus altering both sources and sinks of greenhouse and chemically important trace gases (e.g., carbon dioxide, carbon monoxide, carbonyl sulphide, ozone, and possibly other gases).
These potential changes would contribute to biosphere-atmosphere feedbacks that mitigate or amplify the atmospheric concentrations of these gases.
5. Effects on Materials-
Synthetic polymers, naturally occurring biopolymers, as well as some other materials of commercial interest are adversely affected by UVB radiation.
Today’s materials are somewhat protected from UVB by special additives. Yet, increases in UVB levels will accelerate their breakdown, limiting the length of time for which they are useful outdoors.
Steps to Prevent Ozone layer Depletion-
These are some of the Measure for Minimising Ozone Depletion-
- Use of products which has Chlorofluorocarbons (CFCs) such as hair spray fresheners, cosmetics, and aerosol in plastic containers should be avoided.
- Promote activities such as tree planting and backyard gardening.
- Use Environmental-friendly fertilizers.
- Prevent excessive smoke emission from your vehicle which causes air pollution. Save on gasoline and crude oil through regular maintenance.
- Do not burn plastics and rubber tires.
- World Ozone Day is observed on 16 September to spread awareness about the harmful effects of Ozone depletion and ways to find out preventive measures.
- Buying and using a recycled product.
- Use less heat and air conditioning.
- Buy energy-efficient products.
- Reducing fossil fuel emissions by using public transport and green transport.
- Buy air-conditioning and refrigeration equipment that does not use HCFCs as a refrigerant.
- Buy aerosol products that do not use HCFCs or CFCs as propellants.
- Conduct regular inspection and maintenance of air-conditioning and refrigeration appliances to prevent and minimize refrigerant leakage.
- For existing air-conditioning and refrigeration appliances that operate on HCFCs or CFCs, the refrigerant should be recovered or recycled whenever an overhaul of equipment is to be carried out. Replacing or retrofitting such equipment to operate on non-HCFCs refrigerant should also be considered.
- When motor vehicle air-conditioners need servicing, make sure that the refrigerants are properly recovered and recycled instead of being vented into the atmosphere.
- 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 an 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.
- Maintain air conditioners, as their malfunctions cause CFCs to escape into the atmosphere.
- Ensuring that existing restrictions on ozone-depleting substances are properly implemented and global use of ozone-depleting substances continues to be reduced.
- Ensuring that banks of ozone-depleting substances (both in storage and contained in existing equipment) are dealt with in an environmentally-friendly manner and are replaced with climate-friendly alternatives.
- Reducing the use of ozone-depleting substances applications that are not considered as consumption under the Montreal Protocol.
- Ensuring no new chemicals technologies threats to the ozone layer (e.g. very short-lived substances).
All of this has to do with the Depletion of Ozone layer. I believe I have covered every aspect of this topic. If I missed something, please leave a comment and I’ll do my best to include it.
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Abhishek Tiwary is a blogger by passion and a Quality Engineer by profession. He completed his B.Tech degree in the year 2017. Now working in a reputed firm. He loves to share his knowledge with others.