The ultra violet radiation is readily absorbed by living tissue,and since light at this wavelength has sufficient energy to break chemical bonds,it can be injurious to both plants,animals and human beings. The latest ozone layer depletion news is included at the foot of the page. Pdf causes of ozone layer depletion and its effects on. May 03, 2017 ozone layer is a thin blanketlike layer that spreads over the atmosphere of the earth. Environmental protection agency epa is proud to have been part. However, the ozone layer is destroyed by manmade chemicals known as ozonedepleting substances ods. Ozone layer depletion quiz free online hvac certification.
The ozone layer helps to protect life from harmful ultraviolet radiation. The the causes and effects of global ozone depletion have been illuminated in this paper. The danger and prevention of ozone layer depletion humans cause ozone depletion with air conditioners and refrigerators, of all things. Ozone layer protection european commission europa eu. This ozone layer sustains life on the earth by absorbing a great deal of uv ultra violet light radiating out of sun. A seasonal decrease, or hole, in the ozone layer above antarctica, first discovered in 1982 and reported in 1985, was the first confirmation of a thinning of the layer. Ozone layer is a thin blanketlike layer that spreads over the atmosphere of the earth.
Ozone depletion and climate change environment canada. It forms a natural belt or shield in the upper atmosphere at 20 km to 30 km above earth, also called stratosphere. Ozone layer is also naturally broken down but there is a balance between its formation and natural depletion. When chlorine nitrate, a chemical that ties up chlorine in an ozone safe form, was added to the hypothesis, the expected amount of ozone loss decreased.
Low temperatures, increase in the level of chlorine and bromine gases in the upper stratosphere are some of the reasons that leads to ozone layer depletion. The new halonfree systems have been used successfully in iraq. Depletion of ozone layer has led to increased solar ultra violetuvb radiation at earths surface. Another most feared aspect of pollution is depletion of ozone layer of the stratosphere. Ozone layer depletion and its control measures zilwach. The ozone layer is a natural layer of gas in the upper atmosphere that protects humans and other living things from harmful ultraviolet uv radiation from the sun. Ozone depletion facts and information national geographic.
This can be harmful to skin, and, thankfully, the ozone protects us from much of it. Causes of ozone layer depletion and its effects on human. Once they get there they destroy ozone molecules and cause the ozone layer to become depleted or thinner. The increase in the uvr reaching the earth affects. Ozone layer depletion is one of the most serious problems faced by our planet earth. 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. Ozone layer depletion penn state college of earth and.
The latter phenomenon is referred to as the ozone hole. The term ozone depletion can refer to a number of distinct, but related phenomena. Free chlorine cl atoms then react with ozone molecules, taking one oxygen atom to form chlorine monoxide clo and leaving an oxygen molecule o. Looking back over the scientific investigation of ozone depletion, we can see how the molinarowland hypothesis evolved with new data. Ozone depletion consists of two related events observed since the late 1970s.
The ozone layer forms a most important part of the earths stratosphere as it can absorb most of the uv radiation and prevent it from reaching the surface of the earth. Cfcs are chlorine based substances which used to be widely used in aerosols, refrigerants, and in several. Jul, 2017 ozone layer depletion the emission of ods account for roughly 90% of total depletion of ozone layer in stratosphere. Ozone is a gas that is present in the ozone layer in the stratosphere of the earth. The level from which it extends outward varies with latitude. The causes, mechanism and bioeffects of ozone layer depletion on humans were addressed. Jstor is a digital library of academic journals, books, and primary sources.
Following is the list of some of the main ozone depleting substances and the sources from where they are released. Ozone depleting substances are the substances such as chlorofluorocarbons, halons, carbon tetrachloride, hydrofluorocarbons, etc. Nearly 500 organizations, teams, and individuals from 40 countries have received stratospheric ozone protection awards for their exceptional leadership, personal dedication, and technical achievements. The part of the atmosphere where ozone is most depleted is referred as ozone hole but it is not a real hole just a vast region of the upper atmosphere where there is less ozone than elsewhere. Due to global warming and green house effect most of the heat is trapped in troposphere which is the layer below the stratosphere.
Nearly 90% of earths ozone is in the stratosphere and referred to as the ozone layer. Ozone layer and its depletion ozone it is an allotrope of oxygen, having 3 atoms of oxygen. 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. Ozone layer depletion causes, effects and solutions 7. The ozone layer prevents most ultraviolet uv and other highenergy radiation from penetrating to the earths surface but does. The main reasons of this depletion are the release of organohalogen compounds like chlorofluorocarbons and bromofluorocarbons. Since about the 1970s, there has been a decrease in total volume of the ozone in the ozone layer, of about 4%, per decade. 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 ozonedepleting substances ods. Here we look at the key causes of the thinning of the ozone above our planet. Ppt ozone layer depletion powerpoint presentation free. A single atom of chlorine from a cfc can destroy 100,000 or more molecules of ozone. Ozone layer depletion and its prevention from theory to. Ozone depletion is allowing the uv radiation to earth surface. As a result, the irreversible destruction of the ozone layer was prevented.
At that point, it is no longer free to react with ozone. When chlorine nitrate, a chemical that ties up chlorine in an ozonesafe form, was added to the hypothesis, the expected amount of ozone loss decreased. The ozone layer prevents all uvc from reaching the earths surface. The danger and prevention of ozone layer depletion. Ozone layer definition of ozone layer by the free dictionary. The bestknown and most abundant of the ods are the cfcs. There, it will absorb almost all ultraviolet light which is harmful to many organisms.
These chemicals are found in cleaning agents, aerosols, insulating foam, and refrigerants. Ozone depletion is primarily caused by human activities. Cfcs get banned in 1974 scientists sherry rowland and mario molina discovered the link between the depletion of the ozone layer and cfcs. We care about ozone depletion because a thinner ozone layer allows more uv radiation to reach the earths surface.
The main effect of ozone depletion is an increase in uvb rays reaching the earths surface causes. Hence, cfcs are transporting agents that are responsible for damaging the ozone layer. Overexposure to uv radiation can cause a range of health effects, including skin damage skin cancers and premature aging, eye damage including cataracts, and suppression of the immune system. Ozone layer depletion article about ozone layer depletion.
The ozone layer refers to a region of earths stratosphere that absorbs most of the suns uv radiation. Find out what caused the ozone hole, and how the 1989 montreal protocol sought to put an end to ozone depletion. 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 chlorofluorocarbon and the halons are potent ozone depletors. Many of them can persist in the stratosphere for centuries. A free powerpoint ppt presentation displayed as a flash slide show on id. Pdf on jan 1, 2001, md safiuddin and others published global ozone. Ozone layer the ozone layer is basically naturally occurring gas in the region of stratosphere where ozone particles are accumulated 2. Additional copies may be obtained, free of charge, from.
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. Concentrations of ozonedepleting substances are expected to decline over the coming century, bringing a gradual recovery of the ozone layer. This is apparently found in the lowest region of the stratosphere. Ozone depletion simple english wikipedia, the free. Ozone does not absorb uva light uvb between 280 and 320 nanometers. No one knows for certain how much more ozone depletion will occur. Ozone layer depletion the ozone with chemical formula o 3 is a molecule composed of three atoms of oxygen, reason why it is also known as trioxygen. Why the hole in the atmospheric ozone layer above us. The proteins cells in plants undergo harmful mutations, all due to ultraviolet radiations. Basic ozone layer science ozone layer protection us epa. The ozone layer is mainly found in the lower portion of the stratosphere.
It allows only the required doses of the suns solar energy to reach the earths surface. However, stratospheric ozonewill not recovercompletely until 2060 and the consequent epidemic in skin. Learn what cfcs are, how they have contributed to the ozone hole, and how the 1989 montreal. It is also one of the prime reasons which are leading to global warming. However, the fact that there also exists another layer strong enough to stop the former one is comforting. The first report of depletion in o 3 layer came out in the 1980s by an atmospheric scientist in antarctica. English, french and spanish versions are available free to develop ing countries a.
Ppt ozone layer depletion powerpoint presentation free to. Powerpoint is the worlds most popular presentation software which can let you create professional depletion of ozone layer powerpoint presentation easily and in no time. Ozone layer depletion cause, effects, and solutions. The ozone layer lies approximately 1540 kilometers 1025 miles above the earths surface, in the stratosphere. Ozone is a colourless gas which is found in the stratosphere of our upper atmosphere. Ozone layer depletion the emission of ods account for roughly 90% of total depletion of ozone layer in stratosphere. Ozone layer depletion definition of ozone layer depletion. Presentation on ozone depletion linkedin slideshare. The earths ozone layer ozone layerthe region of the stratosphere containing the bulk of atmospheric ozone. Although ozone is present in small concentrations throughout the atmosphere, most around 90% exists in the stratosphere, a layer 10 to 50 kilometres above the earths surface. Protecting the ozone layer department of the environment. But the one and the most important reason for ozone layer depletion is the production and emission of chlorofluorocarbons cfcs. The main causes of ozone depletion are the various uses of cfcs.
Experts blame ozonelayer depletion on manmade chem icals containing chlorine. Ozone depletion only stops when the chlorine randomly reacts with another molecule to form a longlived, stable substance. What are the causes and effects of ozone depletion. There are also springtime polar tropospheric ozone depletion. About 90 per cent of all ozone formed in this way lies between 15 and 55 kilometres above the earths surface the part of the atmosphere called the stratosphere. Depletion of this layer by ozone depleting substances ods will lead to higher uvb levels, which in turn will cause. Unfortunately, cfcs can eventually find their way into the earths atmosphere and the ozone layer. The ozone layer is a belt of the naturallyoccuring gas ozone that sits at an altitude of between 15 and 30 kilometers above the earth. It contains high concentrations of ozone o3 relative to other parts of the atmosphere. Ozone layer depletion, its causes, effects and control measures. The main things that lead to destruction of the ozone gas in the ozone layer. The depletion of the ozone layer has thus resulted in the birth of a fear in everybodys minds.
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 in the ozone layer is formed by the action of solar ultraviolet light on oxygen. Protecting the ozone layer and reducing global warming undp. Effects and measures to protect ozone layer depletion.
The layer of ozone gas is what which protects us from the harmful ultraviolet radiations of the sun. The depletion of ozone layer leads to an increase in th e amount of harmful uvr at ground level. This is the cause for the nearly 80% of the ozone depletion. This helps you give your presentation on depletion of ozone layer in a conference, a school lecture, a business proposal, in a webinar and business and professional representations. Man has tried hard to deploy protective measures towards controlling the ozone layer from depletion,but this is so. Ozone depletion, ozone hole, ultraviolet radiation. Its consequences, the causal debate, and international cooperation number 6 february 8, 1988 since the announcement of a thinning of the ozone layer over the antarctic by uk scientists in 1985, world attention has been focusing on the causes of this phenomenon. There is a substantial time lag between the time when ods emissions begin to decline and the point at which the ozone layer begins to recover. British science teams in antarctica observe 10% decline in o 3 layer us scientists relying on toms total ozone mapping spectrometer measurements from space claim to observe nothing. When this breakdown of the ozone layer occurs, the earth stands more vulnerable as it. Undps work on ozone layer protection and programme impact. The evaporation of surface water through the stomata of leaves increases, which results in the decreased moisture content of the soil. Thus, ozone layer depletion has become a major concern among the environmentalists.
These gases are carried to the stratosphere layer of atmosphere where. The causes of ozone layer depletion are almost all man made. If each chlorine atom released from a cfc molecule destroyed only one ozone molecule, cfcs would pose very little threat to the ozone layer. Ozone layer depletion, its causes, effects and control. The ozone layer was discovered in 19 by the french physicists charles fabry and henri buisson. It takes years for cfcs and other ozonedepleting compounds to reach the stratosphere. Stratospheric ozone protection awards since 1990, epa has recognized outstanding achievement in ozone layer protection. It is revealed that introduction of chloroflourocarbons cfcs in the environment is the most rated cause of said depiction.
Far above earths surface, the ozone layer helps to protect life from harmful ultraviolet radiation. There, sunlight could free the chlorine or bromine atoms to form chlorine monoxide or other chemicals, which would deplete upperatmospheric ozone. The thinning is most pronounced in the polar regions, especially over antarctica. Unlike oxygen o2, ozone has a strong scent and is blue in color. Ozone absorbs a band of ultraviolet radiation called uvb. But even a healthy, thick ozone layer doesnt prevent all uvb from reaching the earth. Global warming also leads to ozone layer depletion. 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. The ongoing recovery of the planets ozone layer is being significantly affected by volcanic eruptions. Apr 18, 2019 the ozone layer helps to protect life from harmful ultraviolet radiation. Ozone layer depletion ozone loss was first detected in the stratosphere over the antarctic.
Feb 12, 2018 far above earths surface, the ozone layer helps to protect life from harmful ultraviolet radiation. The ozone layer protects the surface of the earth and its phenomena from stray rays from the sun. List of books and articles about ozone layer online. This helps you give your presentation on depletion of ozone layer in a conference, a school lecture, a business proposal, in a webinar and business and professional representati. This, in turn, will lead to the breakdown of ozone. As a result the total amount of ozone remains constant. Fire extinguishers contain halons and methyl bromide in the form of pesticides can also be also a cause for the depletion. Cfcs, hcfcs, halons, methyl bromide, carbon tetrachloride, and methyl chloroform. 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.
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