Polar vortex in the previous posts, we have studied about tropical cyclones and extra tropical cyclones temperate cyclone. The proteins cells in plants undergo harmful mutations, all due to ultraviolet radiations. A free powerpoint ppt presentation displayed as a flash slide show on id. The evaporation of surface water through the stomata of leaves increases, which results in the decreased moisture content of the soil. Unfortunately, cfcs can eventually find their way into the earths atmosphere and the ozone layer. Safeguarding earths protective ozone layer became a. 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 layerthe ozone layer is a deep layer in thestratosphere, encircling the earth,that has large amounts of ozone in it. When highenergy ultraviolet rays uvc strike an oxygen. Here we will study polar vortex circumpolar vortex which is a polar cyclone. Unlike oxygen o2, ozone has a strong scent and is blue in color.
The term ozone depletion can refer to a number of distinct, but related phenomena. 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. As controlled ozone depleting substances decline, the evolution of the ozone layer in the second half of the 21st century will largely depend on the atmospheric. The 1987 montreal protocol on substances that deplete the ozone layer began the phaseout of cfcs in 1993 and sought to achieve a 50 percent reduction in. Frequently asked questions about the ozone layer ozone. A dynamic equilibrium is maintained between the formation and decomposition of ozone. Pdf causes of ozone layer depletion and its effects on. What are the causes and effects of ozone depletion. The ozone layer is mainly found in the lower portion of the stratosphere. The ozone layer refers to a region of earths stratosphere that absorbs most of the suns uv radiation.
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. Pdf depletion of the ozone layer and its consequences. Ozone depletion ozone depletion ozone layer recovery. The ozone layer contains less than 10 parts per million of ozone the ozone layer absorbs 9799% of the suns mediumfrequency ultraviolet light from about 200 nm to 315 nm wavelength, which otherwise would potentially damage exposed life forms near the surface the ozone layer was discovered in 19 by the french physicists charles fabry and. The ozone layer was discovered in 19 by the french physicists charles fabry and henri buisson. Through that agreement and its subsequent amendments and adjustments, many nations of the world have carried out policies to. Above northern europe, the decrease is estimated to be about 3. When cfc is released into the atmosphere, they mix with atmospheric. The recognition of the dangers presented by chlorine and bromine to the ozone layer spawned an international effort to restrict the production and the use of cfcs and other halocarbons. Ppt ozone layer depletion powerpoint presentation free. Project ozone layer depletion pdf the stratospheric ozone layer forms a thin shield in the upper atmosphere, protecting life on earth from. Cfcs, hcfcs, halons, methyl bromide, carbon tetrachloride, and methyl chloroform.
Ozone depletion is primarily caused by human activities. The the causes and effects of global ozone depletion have been illuminated in this paper. How severe is the depletion of the antarctic ozone layer. The ozone layer is important for blocking most of the harmful radiation that comes from the sun.
Ozone layer the ozone layer is basically naturally occurring gas in the region of stratosphere where ozone particles are accumulated 2. It is present in traces less than 1 ppm in the atmosphere. Ozone layer depletion is one of the major environmental issues which is getting thinner day by day as a. It protects us from harmful uv rays that can have serious effects on animals, biodiversity and peoples health, including skin cancer and eye cataract.
Within the stratosphere, the ozone layer is the portion that contains the highest proportion of. It shields the entire earth frommuch of the harmful uv radiationthat comes from the sun 3. Human activities that can damage or affect the ozone. The ozone layer is made up of ozone molecules, like ozzy ozone, and forms a thin shield high up in the sky. It was first identified in 1970s due to the advent of supersonic aircraft, which fly in the lower stratosphere and emit nitrogen oxides. However, the ozone layer is destroyed by manmade chemicals known as ozonedepleting substances ods. The earths ozone layer is mainly found in the lower portion of the stratosphere from approximately 20 to 30.
Apr 18, 2019 the ozone layer helps to protect life from harmful ultraviolet radiation. This is the reason the ozone hole found over the polar region of earth. Nearly 500 organizations, teams, and individuals from 40 countries have received stratospheric ozone protection awards for their exceptional leadership, personal dedication, and technical achievements. Quantifying contributions of chlorofluorocarbon banks to. In the 1980s, scientists began finding clues that the ozone layer was being depleted. Experts blame ozonelayer depletion on manmade chemicals containing chlorine and bromine that are emitted from a. 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.
It has been found that this protective ozone layer is getting depleted because of the presence of cfc chlorofluorocarbon compounds. The assessment may be reproduced or excerpted, without. List of books and articles about ozone layer online. 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. It is formed slowly over the period of 2500 million years. The natural distribution of ozone around the earth is. The thinning is most pronounced in the polar regions, especially over antarctica. The layer shields the entire earthfrom much of the harmful ultravioletradiation that comes from the sun. For nearly a billion years, ozonemolecules in the atmosphere haveprotected life on earth from theeffects of. Ozone layer depletion, its causes and its effects scribd. There is a burgeoning need to reduce the production of industrial products causing ozone depletion and global warming. There, it will absorb almost all ultraviolet light which is harmful to many organisms. Nearly 90% of earths ozone is in the stratosphere and referred to as the ozone layer.
Scribd is the worlds largest social reading and publishing site. As a result the total amount of ozone remains constant. Progress report 2003 united nations environment programme, environmental e. One example of ozone depletion is the annual ozone hole over antarctica that has occurred during the antarctic spring since the early 1980s.
This ozone layer sustains life on the earth by absorbing a great deal of uv ultra violet light radiating out of sun. Ozone o3 is a stratospheric layer that plays important role in providing support to humans for their survival. Ozone layer depletion is one of the most serious problems faced by our planet earth. Since there is no other known source of chlorine monoxide, finding this chemical in the upper atmosphere would strongly support the idea that chlorine is destroying ozone. Ozone is a gas that is present in the ozone layer in the stratosphere of the earth. Ozone depletion biology science fair project ideas. An international consensus about the causes and effects of ozone depletion has emerged. An international agreement known as the montreal protocol on substances that deplete the ozone layer was reached in 1987. This depletion makes humans more vulnerable to the uvb rays which are known to cause skin cancer as well as other genetic deformities. These chemicals are found in cleaning agents, aerosols, insulating foam, and refrigerants. You can find maps of the ozone layer and compare different regions of the globe for ozone coverage. Within the stratosphere, the ozone layer is the portion that contains the highest.
It addressed the im portance of conservation of ozone layer and established. At the end of 20, 258 projects have been committed for an. Humans have introduced gases and chemicals into the atmosphere that have rapidly depleted the ozone layer in the last century. 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. Stratospheric ozone protection awards since 1990, epa has recognized outstanding achievement in ozone layer protection. Ozone depletion refers to the wearing out or reduction of the amount of ozone in the stratosphere. Since about the 1970s, there has been a decrease in total volume of the ozone in the ozone. Ozone present in the stratosphere forms a protective layer and known as ozone layer, ozonosphere or ozone umbrella its concentration in atmosphere is about 10 ppm. Les diablerets, switzerland by jeanpierre pommereau, june 2010.
Most ozone is found in the stratosphere upper part of the atmosphere, more than 10 to 16 kms from the surface of the earth. There are natural processes that create and destroy ozone in the stratosphere. Once they get there they destroy ozone molecules and cause the ozone layer to become depleted or thinner. These compounds go tot the ozone layer through the air and reach the ozone then produce the halogens which ultimately produced oxygen o2 from the ozone o3 hence causing the depletion of ozone. The ozone layer protects living things from harmful ultraviolet rays from the sun. Global warming is caused by the greenhouse effect, which is essential to life as we know it on planet earth. The severe depletion of the antarctic ozone layer known as the ozone hole occurs because of the special meteorological and chemical conditions that exist there when the very low winter temperatures in the antarctic stratosphere cause polar stratospheric clouds pscs to form which are isolated from stratospheric air in the polar vortex. The latest ozone layer depletion news is included at the foot of the page. Ozone depletion simple english wikipedia, the free encyclopedia. The main effect of ozone depletion is an increase in uvb rays reaching the earths surface causes. The rate of degradation of ozone layer is estimated to be around 1% per 10 years.
In the upper atmosphere, atmospheric gases absorbs the suns radiation, get ionized, and release molecules. Testing the hypothesis of ozone depletion 3 of 3 chlorine monoxide is one of the products of ozone destruction. 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. More recently, fears have emerged about significant ozone depletion over the arctic, closer to the more populous regions of the northern hemisphere. The layer of ozone gas is what which protects us from the harmful ultraviolet radiations of the sun.
Protecting the ozone layer department of the environment. Ozone depleting substances are those substances which deplete the ozone layer. Ozone layer depletion causes and effects of ozone layer. In the 1960s, a normal ozone layer is clearly evident in the october average profile, with a peak near 16 kilometers altitude. Changes in co 2, n 2 o, and ch 4 will have an increasing influence on the ozone layer as odss decline. Ozone is a colourless gas which is found in the stratosphere of our upper atmosphere. In response to this and additional fears about more widespread global ozone depletion, the montreal protocol on substances that deplete the ozone layer was implemented in 1987. Ozone layer is a thin, fragileshield that contains relatively highconcentrations of ozone.
Ozone depletion is largely a result of manmade substances. The question is often asked why the world moved so quickly in dealing with ozone layer depletion, yet has moved so slowly in addressing the equally critical problem of climate change. 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. A global thinning of the ozone layer results as ozone rich air from the remaining ozone layer flows into the ozone poor. Ozone layer depletion cause, effects, and solutions. Mechanism of ozone depletion the reason for ozone depletion was earlier explained by various theories. There are many situations where human activities have. Is there a difference in ozone coverage between different hemispheres. It contains high concentrations of ozone o3 relative to other parts of the atmosphere.
This legally binding international treaty called for participating developed nations to reduce the use of cfcs and other ozone depleting substances. 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. Find out what caused the ozone hole, and how the 1989 montreal protocol sought to put an end to ozone depletion. It is an essential factor for many global, biological and environmental phenomena. The ozone layer and its depletion linkedin slideshare. Depletion of stratospheric ozone o3, as commonly known as the hole in the ozone layer, is an issue of international concern. Causes of ozone layer depletion and its effects on human. Effects and measures to protect ozone layer depletion. The ozone layer is a belt of naturally occurring ozone gas that sits 9. The vienna convention for protection of ozone layer was adopted by 43 nations in 1985. 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. My teaching and textbook1 have always covered many physicsrelated social issues, including stratospheric ozone depletion and global warming. 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. It protects life on earth from the suns ultraviolet uv rays.
Ozone is unstable and decomposes to molecular oxygen. Measurements from satellitebased instruments show that this area of very low ozone concentration has developed over antarctica every year since about 1975. 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. Ozone layer depletion causes, effects and solutions 7. The increased use of humanproduced gases such as chlorofluorocarbons cfcs has led to a magnified springtime depletion of the protective ozone layer at both earths poles, especially over antarctica, a phenomenon well known as the ozone hole. In the 199020 average profile, a broad minimum centered near 16 kilometers now occurs, with ozone values reduced by up to 90% of normal values.
Why the hole in the atmospheric ozone layer above us. Presentation on ozone depletion linkedin slideshare. Another most feared aspect of pollution is depletion of ozone layer of the stratosphere. Nasa provides daily images, data, and information from satellite instruments that monitor the ozone layer and the ozone hole ozone holea thinning break in the stratospheric ozone layer. The ozone layer has the capacity to absorb almost 9799% of the harmful ultraviolet radiations that sun emits and which can produce long term devastating effects on human beings as well as plants and animals coohill, t. To the point where a seasonal hole in the ozone layer began to appear above the antarctic. Following is the list of some of the main ozone depleting substances and the sources from where they are released. Ozone depletion results in an increase of uvb radiation, but the shorter the wavelength, the stronger the increase within the uvb range. 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. Global warming and ozone layer depletion are two different problems see the sidebar misconceptions about global atmospheric change on page 95. Environmental studies ozone depletion tutorialspoint. Ozone depletion facts and information national geographic. 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.
Ozone layer depletion, its causes and its effects free download as powerpoint presentation. It is also one of the prime reasons which are leading to global warming. Apr 14, 2017 the ozone hole is an area where the amount of ozone in the upper atmosphere is much lower than normal. Cfcs get banned in 1974 scientists sherry rowland and mario molina discovered the link between the depletion of the ozone layer and cfcs. Designation of amount of such depletion as an ozone hole is made when the detected amount of depletion.
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