The term ozone depletion can refer to a number of distinct, but related phenomena. Ozone depleting substances are the substances such as chlorofluorocarbons, halons, carbon tetrachloride, hydrofluorocarbons, etc. Environmental studies ozone depletion tutorialspoint. The ozone layer has been depleted gradually since 1980 and now is about an average of 4% lower over the globe. Cfcs get banned in 1974 scientists sherry rowland and mario molina discovered the link between the depletion of the ozone layer and cfcs. Ozone layer depletion article about ozone layer depletion. As a result the total amount of ozone remains constant. The ozone layer helps in absorbing the ultraviolet uv rays of the sun which are harmful to human beings. Depletion to ozone layer depletion does not affect a region or a country. Ozone layer depletion is one of the major environmental issues which is getting thinner day by day as a result of increasing pollution.
The sun propagates ultraviolet radiations which as an adverse effect on living beings. This timeline highlights the average area of the ozone hole between september 7th and october th as observed by nasa spacedbased instruments see colored bars and scale. There are many situations where human activities have. For nearly a billion years, ozonemolecules in the atmosphere haveprotected life on earth from theeffects of. Project ozone layer depletion pdf the stratospheric ozone layer forms a thin shield in the upper atmosphere, protecting life on earth from. Ozone depletion over india with so much worry about the rapid ozone depletion taking place in various parts of the earth, indian scientists are closely monitoring the ozone layer over india for possible depletion. The layer of ozone gas is what which protects us from the harmful ultraviolet radiations of the sun.
Dramatically every spring you may have heard this called the ozone hole. This is not really a hole through the ozone layer, but rather a large area of the stratosphere with extremely low amounts of ozone. The ozone layer depletion is a major concern and is associated with a number of factors. Most ozone is found in the stratosphere upper part of the atmosphere, more than 10 to 16 kms from the surface of the earth. Money and time are being spent on ozone repair, but the problem still exists. The thickness of ozone layer is measured in dobson units, where 1 du. View the latest status of the ozone layer over the antarctic, with a focus on the ozone hole. Solomon and albritton, 1992 as a measure of the effectiveness of a given compound in removing ozone, relative to a standard compound, which is taken to be cfc11.
A combination of low temperatures, elevated chlorine, and bromine concentrations in the upper stratosphere are responsible for the destruction of ozone. The latter phenomenon is referred to as the ozone hole. When ozone level decreases below 200 du, the condition is called ozone hole mechanism of ozone depletion includes two processes, which are. Depletion of stratospheric ozone o3, as commonly known as the hole in the ozone layer, is an issue of international concern. As humans are heavily dependent on crops for food so there is a great chance if depletion of ozone layer is not checked it may cause seriously. It is an essential factor for many global, biological and environmental phenomena. The ozone layer is a protective shield that blocks the suns harmful ultraviolet rays. The health effect on humans from ozone depletion is widely varied. Without the layer of ozone in the atmosphere, it would be very difficult for anything to survive on the surface. Does depletion of the ozone layer increase groundlevel ultraviolet radiation. A polar vortex is a large pocket of very cold air, typically the coldest air in the northern hemisphere, which sits over the polar region during the winter season. Stratospheric pollution ozone formation and breakdown. Global warming and ozone layer depletion are two different problems see the sidebar misconceptions about global atmospheric change on page 95.
Mar 21, 2020 ozone depletion, gradual thinning of earth s ozone layer in the upper atmosphere caused by the release of chemical compounds containing gaseous chlorine or bromine from industry and other human activities. Ozone layer depletion causes increased uv radiation levels at the earths surface, which is damaging to human health. Ozone absorbs a band of ultraviolet radiation called uvb. The average depletion exceeds the natural variability of the ozone layer. What is important to keep in mind is the fact that prevention of ozone layer depletion is so very important because it directly affects the well being of the people. An international consensus about the causes and effects of ozone depletion has emerged. These chemicals are found in cleaning agents, aerosols, insulating foam, and refrigerants. It contains high concentrations of ozone o3 relative to other parts of the atmosphere. The ozone layer is a region of the stratosphere containing ozone, or o3 gas. Without ozone, the suns intense uv radiation would sterilize the earths surface. Ozone is a colourless gas which is found in the stratosphere of our upper atmosphere. Ozone depletion is primarily caused by human activities. A close look at the evolution at the life on earth reveals that initially.
The layer shields the entire earthfrom much of the harmful ultravioletradiation that comes from the sun. Negative effects include increases in certain types of skin cancers, eye cataracts and immune deficiency disorders. Since ozone is the earths protection against ultraviolet uv radiation, a reduction in the ozone layer causes more uvb wavelengths to reach the surface of the earth. Ozone layer depletion is simply the wearing out reduction of the amount of ozone in the stratosphere. Unfortunately, cfcs can eventually find their way into the earths atmosphere and the ozone layer. Unlike pollution, which has many types and causes, ozone depletion has been pinned down to one major human activity. What we all need to understand is the idea that we all are going to have to face the repercussions of ozone layer depletion. The ozone loss is very small near the equator and increases with latitude toward the poles. The uvb wavelengths cause skin cancer, sunburn, aging and.
Find out what caused the ozone hole, and how the 1989 montreal protocol sought to put an end to ozone depletion. In the 1980s, scientists began finding clues that the ozone layer was being depleted. This layer absorbs the radiations and prohibits them from entering the outer surface of the earth. The world meteorological or ganization wmo, 1995 predicted that the depletion of the ozone layer peaked around 1998 and the layer would slowly recover by 2045 12. The earths ozone layer is mainly found in the lower portion of the stratosphere from approximately 20 to 30.
Ozone depletion, gradual thinning of earth s ozone layer in the upper atmosphere caused by the release of chemical compounds containing gaseous chlorine or bromine from industry and other human activities. Ozone is a triatomic form of oxygen o 3, found in the earths atmosphere. Uv rays can cause sunburn and damage the dna, the ozone layer absorbs most of the harmful radiations and protects us. It was first identified in 1970s due to the advent of supersonic aircraft, which fly in the lower stratosphere and emit nitrogen oxides. Ozone is harmful at ground level but high up the atmosphere ozone layer plays a vital role in the protection of all living beings. Destruction of the upper atmospheric layer of ozone gas, caused by substances formed from breakdown of ozone depleting substances. This is the cause for the nearly 80% of the ozone depletion. Ozone depletion consists of two related events observed since the late 1970s. The ozone layer helps to protect life from harmful ultraviolet radiation. Frequently asked questions about the ozone layer us epa. Satellite instruments monitor the ozone layer, and we use their data to create the images that depict the amount of ozone. Depletion of this layer by ozone depleting substances ods will lead to higher uvb levels, which in turn will cause increased skin cancers and cataracts and potential damage to some marine organisms, plants, and plastics. The ozone layer is made up of ozone molecules, like ozzy ozone, and forms a thin shield high up in the sky. List of books and articles about ozone layer online.
Depletion meaning in the cambridge english dictionary. The ozone layer and its depletion linkedin slideshare. However, the ozone layer is destroyed by manmade chemicals known as ozone depleting substances ods. Causes and effects of ozone layer depletion that are. What are the causes and effects of ozone depletion. May 30, 2017 by knowing the statistics about ozone layer depletion, we can keep working hard at restoring our planet so that it is available for future generations to enjoy. Uv radiation also affects terrestrial and aquatic ecosystems, altering growth, food chains and biochemical cycles. Nearly 90% of earths ozone is in the stratosphere and referred to as the ozone layer. In the layer surrounding the earths surface, the troposphere, ground level or bad ozone is an air pollutant that is a key ingredient to. The emission of ozone depleting substances has been damaging the ozone layer.
Pdf causes of ozone layer depletion and its effects on. Ozone layer depletion cause, effects, and solutions. Ozone depletion facts and information national geographic. Chlorofluorocarbons or the cfc are the main cause of ozone layer depletion. The montreal protocol on substances that deplete the ozone layer a protocol to the vienna convention for the protection of the ozone layer is an international treaty designed to protect the ozone layer by phasing out the production of numerous substances that are responsible for ozone depletion. Ozone layer the ozone layer is basically naturally occurring gas in the region of stratosphere where ozone particles are accumulated 2. Ozone o3 is produced in the stratosphere by the intense solar radiation causing photodissociation of the diatomic oxygen molecule o2. As a result of its chemical composition, ozone is regarded as a special type of oxygen as it contains three oxygen molecules o3 as opposed to the usual two oxygen molecules o2. Ozone layer definition of ozone layer by the free dictionary.
The ozone layer is mainly found in the lower portion of the stratosphere. The ozone layer is mainly found in the lower portion of the stratosphere, about 20 to 30 km 12 to 19 miles above the earth, though the thickness varies seasonally and geographically. Ozone depletion atmospheric ozone layer depletion is a serious problem currently facing the world. Protecting the ozone layer department of the environment. The main causes responsible for the depletion of the ozone layer are listed below. There are also springtime polar tropospheric ozone depletion.
The natural distribution of ozone around the earth is. The main effect of ozone depletion is an increase in uvb rays reaching the earths surface causes. This website addresses stratospheric ozone issues, including the science of ozone depletion, epas regulatory approach to protecting the ozone layer, epa. Depletion of ozone layer is also causing the problem of food shortage to humans. Polar vortex in the previous posts, we have studied about tropical cyclones and extra tropical cyclones temperate cyclone. Ozone layer is also naturally broken down but there is a balance between its formation and natural depletion. You can find maps of the ozone layer and compare different regions of the globe for ozone coverage.
Ozone layer depletion, its causes and its effects scribd. Ozone depletion potential an overview sciencedirect topics. In fact whole world is vulnerable to its after affects. The third body m absorbs the excess energy liberated by the above reaction and there by stabilise the o 3 ozone molecule. The level from which it extends outward varies with latitude. Since about the 1970s, there has been a decrease in total volume of the ozone in the ozone. A global thinning of the ozone layer results as ozone rich air from the remaining ozone layer flows into the ozone poor. Electromagnetic energy coming from the sun is absorbed by the earth, which. It protects life on earth from the suns ultraviolet uv rays. Within the stratosphere, the ozone layer is the portion that contains the highest. Ozone is a naturally occurring gas that is found in two layers of the atmosphere. The concept of ozone depletion potential odp is widely used wuebbles et al. Ozone depletion simple english wikipedia, the free encyclopedia. Even the proponents of humaninduced ozone depletion are starting to realize that the thinning of the ozone layer is a natural phenomenon that just waxes and wanes.
The causes, mechanism and bioeffects of ozone layer depletion on humans were addressed. Once they get there they destroy ozone molecules and cause the ozone layer to become depleted or thinner. Ozone depleting substances are those substances which deplete the ozone layer. Addressing ozone layer depletion ozone layer protection. Frequently asked questions about the ozone layer ozone. In semiconductor physics, the depletion region, also called depletion layer, depletion zone, junction region, space charge region or space charge layer, is an insulating region within a conductive, doped semiconductor material where the mobile charge carriers have been diffused away, or have been forced away by an electric field. Industries that manufacture things like insulating foams, solvents, soaps, cooling things like air conditioners. Causes, effects and solutions of ozone layer depletion. Fire extinguishers contain halons and methyl bromide in the form of pesticides can also be also a cause for the depletion. The thinning is most pronounced in the polar regions, especially over antarctica. Why the ozone layer is vital to life on earth the ozone layer is a protective shield that blocks the suns harmful ultraviolet rays from reaching the earths surface. The ozone layer lies approximately 1540 kilometers 1025 miles above the earths surface, in the stratosphere. The ozone layer is a deep blanket in the stratosphere made up of comparatively high concentration of the ozone.
Ozone o3 is a stratospheric layer that plays important role in providing support to humans for their survival. The ozone layer was discovered in 19 by the french physicists. To the point where a seasonal hole in the ozone layer began to appear above the antarctic. Ozone depletion occurs when the natural balance between the production and destruction of ozone in the stratosphere is tipped in favour of destruction. It has been found that this protective ozone layer is getting depleted because of the presence of cfc chlorofluorocarbon compounds. The ozone layer refers to a region of earths stratosphere that absorbs most of the suns uv radiation. Thus, ozone layer depletion has become a major concern among the environmentalists. Ozone layer and its depletion animation mcgrawhill animations.
Ozone and environment ozone o3 a gas composed of three atoms of oxygen bluish gas that is harmful to breathe nearly 90% of the earths ozone is in the stratosphere and is referred to as the ozone layer ozone absorbs a band of ultraviolet radiation called uvb ozone depleting substances ods. Uv radiations are disturbing developmental and physiological processes which is decreasing the productivity of crops. Ozone is unstable and decomposes to molecular oxygen. Increasing production of cfcs was stopped by 1993 as a result of the united nations montreal protocol on substances that deplete the ozone layer. Presentation on ozone depletion linkedin slideshare. One example of ozone depletion is the annual ozone hole over antarctica that has occurred during the antarctic spring since the early 1980s. The production and emission of chlorofluorocarbons cfcs, is the leading cause of ozone layer depletion. Is depletion of the ozone layer the principal cause of climate change.
Ozone depletion is the process of destruction of the ozone layer which can cause adverse effects on the living forms by many pollutants releases out from the vehicles, industries etc. It is found largely in the stratosphere that extends from about 6 km at the poles and 17 km at the equator to about 50 km above the earths surface. The increase in the levels of uv rays lead to high rate of skin cancer and eye related problems. This depletion makes humans more vulnerable to the uvb rays which are known to cause skin cancer as well as other genetic deformities. Apr 18, 2019 the ozone layer helps to protect life from harmful ultraviolet radiation. Ozone layer depletion causes, effects and solutions 7. Humans have introduced gases and chemicals into the atmosphere that have rapidly depleted the ozone layer in the last century. How large is the depletion of the global ozone layer. This stopped increasing ozone depletion by 1995, stopping increases in global temperature by 1998. Ozone layer depletion, its causes and its effects free download as powerpoint presentation. Cfcs, hcfcs, halons, methyl bromide, carbon tetrachloride, and methyl chloroform.
Depletion of the ozone layer occurs globally, however, the severe depletion of the ozone layer over the antarctic is often referred to as the ozone hole. Ozone layer depletion is one of the most serious problems faced by our planet earth. At the end of 20, 258 projects have been committed for an. Jan 30, 2012 the ozone layerthe ozone layer is a deep layer in thestratosphere, encircling the earth,that has large amounts of ozone in it. But many researchers do not agree with these predictions,14 and express their.
Role of radicals in ozone formation and depletion in the stratosphere duration. Project report on ozone depletion environmental pollution. There, it will absorb almost all ultraviolet light which is harmful to many organisms. Have reductions of ozone depleting substances under the montreal protocol also protected earths climate. There is a corresponding hole over the arctic that similarly appears in the spring, although in some years warmer winters there do not result in a major depletion of the ozone layer. Ozone is formed by photochemical reaction, followed by three body reaction. Ozone depletion over india with so much worry about the rapid ozone depletion taking place in various parts of the earth, indian scientists are closely monitoring the ozone layer over india for possible depletion trends. The ozone layer is important for blocking most of the harmful radiation that comes from the sun. The ozone layer protects living things from harmful ultraviolet rays from the sun.
Is there a difference in ozone coverage between different hemispheres. Global warming is caused by the greenhouse effect, which is essential to life as we know it on planet earth. Ozone depletion is largely a result of manmade substances. The ozone layer is a belt of naturally occurring ozone gas that sits 9. But through domestic and international action, the ozone layer is healing and should fully recover by about 2065. Ozone is a gas in the atmosphere that protects everything living on the earth from harmful ultraviolet uv rays from the sun. Increased depletion has recently started occurring over the arctic as well. Causes of ozone layer depletion and its effects on human. It is also one of the prime reasons which are leading to global warming. Prolonged exposure to uvb radiation is linked to skin cancer, genetic damage and immune.
Ozone depletion definition ozone depletion is the term commonly used to describe the thinning of the ozone layer in the stratosphere. A dynamic equilibrium is maintained between the formation and decomposition of ozone. Following is the list of some of the main ozone depleting substances and the sources from where they are released. Click any map image to bring up a new page with a highresolution image. Here we will study polar vortex circumpolar vortex which is a polar cyclone. Ozone depletion caused by cfcs explains the onset and termination of recent global warming. The ozone layer protects humans, animals, and plants from harmful ultraviolet rays. Ozone depletion refers to the wearing out or reduction of the amount of ozone in the stratosphere. Lets have a look at some of the solutions to ozone layer depletion. Ozone in the stratospherea layer of the atmosphere between 15 and 50 kilometers 10 and 31 miles above usacts as a shield to protect earths surface from the suns harmful ultraviolet radiation. When cfc is released into the atmosphere, they mix with atmospheric. Ozone layer, region of the upper atmosphere, between roughly 15 and 35 km 9 and 22 miles above earths surface, containing relatively high concentrations of ozone molecules.
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