Ozone is formed by photochemical reaction, followed by three body reaction. Ozone layer depletion is one of the major environmental issues which is getting thinner day by day as a. There have been several concerns about ozone depletion. What does your graph tell you about what has happened to the thickness of the ozone layer during the period from 1956 to 1995. In 1985, the scientists published an article in nature announcing that stratospheric ozone over antarctica was reduced 40% in september, the end of the austral winter. The term ozone hole is applied when the depletion level is below 200 dobson unit d. The ozone hole was much more seen as a hot issue and imminent risk compared to global climate change, as lay people feared a depletion of the ozone layer ozone shield risked increasing severe consequences such skin cancer, cataracts, damage to plants, and reduction of plankton populations in the oceans photic zone. Ozone layer depletion causes, effects and solutions 7. Twenty questions and answers about the ozone layer. The ozone layer thus plays an important role by preventing the harmful uv radiations from penetrating into the earths lower atmosphere the troposphere. Following is the list of some of the main ozone depleting substances and the sources from where they are released. Ppt ozone layer depletion powerpoint presentation free. Ozone hole is the area of the earths atmosphere where abnormal reductions of ozone occur, it is an annual phenomenon observed during the spring in the polar regions and is usually followed by a recovery during the summer.
Ozone depletion consists of two related events observed since the late 1970s. Sep 30, 2019 the ozone hole develops as result of this process. Ozone depletion and land plants the greatest risks connected with the depletion of ozone in the stratosphere are ecological. The latter phenomenon is referred to as the ozone hole. Pdf there are many situations where human activities have significant effects on the environment. The site contains sections on ozone science, the regulatory approach to protecting the ozone layer, and educational information on sun safety.
Jan 07, 2016 ozone hole ozone depletion at south pole polar vortex and ozone depletion are two distinct but related phenomena. Ozone is a minor constituent of the stratosphere 110 ppm. These chemicals are found in cleaning agents, aerosols, insulating foam, and refrigerants. Find out what caused the ozone hole, and how the 1989 montreal protocol sought to put an end to ozone depletion. 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 is a steady decline of about 4% in the total volume of ozone in earths stratosphere. The problems and causes associated with ozone depletion arise from human activities. One of the main reasons for the widespread concern about depletion of the ozone layer is the anticipated increase in the amounts of ultraviolet radiation received. This website addresses stratospheric ozone issues, including the science of ozone depletion, epas regulatory approach to protecting the ozone layer, epa. The ozone layer helps to protect life from harmful ultraviolet radiation. View the latest status of the ozone layer over the antarctic, with a focus on the ozone hole. Satellite instruments monitor the ozone layer, and we use their data to create the images that depict the amount of ozone.
Timeline of stratospheric ozone depletion and observations. Generally, we find thinning or depletion of the ozone layer to the extent of ozone hole creation over the southern pole i. Resent research suggests that the strength of the polar vortex from any given year is directly correlated to the size of the ozone hole. What is an ozone hole and causes and effects of ozone.
Causes of ozone layer depletion and its effects on human. Clo is a highly reactive gas that is involved in catalytic ozone destruction cycles throughout the stratosphere see q9. Every year, since at least 1978, there is a sudden, rapid decrease in the stratospheric ozone levels at the end of the antarctic winter. The arctic the arctic stratosphere in winterspring 2011 was particularly cold, which led to large ozone depletion as expected under these. The so called hole in ozone layers simply means that above some continents specifically antarctica, asia and parts of south america the mesosphere and stratosphere have lost their original level of ozone content. Causes, effects and solutions of ozone layer depletion.
Ozone layer depletion is one of the major environmental issues which is getting thinner day by day as a result of increasing pollution. Marusek 24 february 2005 introduction the earth is surrounded by a thin layer of ozone in the middle atmosphere stratosphere about 25 kilometers above the earths surface. Ozone in the stratospherea layer of the atmosphere between 15 and 50 kilometers 10 and 31. This map shows a satellite ozone map for 10 september 2000, when ozone depletion was close to its maximum. The third body m absorbs the excess energy liberated by the above reaction and there by stabilise the o 3 ozone molecule. How the ozone hole forms the ozone hole is not really a hole but a thinning of the ozone layer over the south polar region. There are many causes for ozone depletion, but the most important process in both trends is.
Ozone depletion ozone depletion information from the united states environmental protection agency. The main effect of ozone depletion is an increase in uvb rays reaching the earths surface causes. The origin of the ozone hole natural or anthropological james a. Ozone in the lower atmosphere contributes to global warming and climate change. Ozone depletion, ozone hole, ultraviolet radiation. Scientific research reveals stratospheric ozone layer depletion has adverse environmental and human health effects. The troposphere is the layer where most weather activity. Ozone concentration at the center of ozone hole 15 ozone hole over continents comparison 1996 16 image of the ozone hole over the south pole july 10 2003 17 image of the ozone hole over the north pole july 10 2003 18 ozone status full day global image, july 9th 2003 19 effects of uv rays on aquatic ecosystems.
Ozone hole ozone depletion at south pole polar vortex and ozone depletion are two distinct but related phenomena. Ozone depletion by halogen source gases occurs glob ally. Ozone depletion facts and information national geographic. The partitioning of chlorine between active forms that destroy ozone and inert reservoirs that sequester it is a central part of the framework for our understanding of the 40. Ground ozone concentration is lower in polar and equatorial regions.
Ppt ozone layer depletion powerpoint presentation free to. 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 depletion of ozone layer is a global phenomena both in terms of cause and effect. Apr 18, 2019 the ozone layer helps to protect life from harmful ultraviolet radiation.
Ozone hole activity marcias science teaching ideas. Ozone depletion is primarily caused by human activities. Oct 18, 2018 ozone depletion ozone depletion information from the united states environmental protection agency. Ozone depletion and climate change environment canada. 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. This timeline highlights the average area of the ozone hole between september 7th and october th as observed by nasa spacedbased instruments see.
Ozone depletion and climate change, or ozone hole and global warming in more popular terms, are environmental challenges whose connections have been explored and which have been compared and contrasted, for example in terms of global regulation, in various studies and books there is widespread scientific interest in better regulation of climate change, ozone depletion and air pollution, as. The earth is protected from excessive ultraviolet rays. Schonbein in the year 1840 confirmed its existence and jacqueslouis soret rooted the chemical formula of ozone as o 3 and proved that ozone is an allotropic form of oxygen. 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.
In most years, the maximum area of the hole is bigger than the antarctic continent itself. May 11, 2020 view the latest status of the ozone layer over the antarctic, with a focus on the ozone hole. Instruments on the ground and on satellites, balloons, and aircraft. The severe depletion of the ozone layer in any particular area is called ozone hole. The antarctic ozone hole continues to occur each spring, as expected for the current ods abundances. Ozone depletion ends when reactive halogen gases are removed by rain and snow in the troposphere and deposited on earths surface.
This severe depletion creates the socalled ozone hole that can be seen in images of antarctic ozone, made using satellite observations. Much larger decrease in stratospheric ozone is observed around earths polar regions. The ozone layer protects living things from harmful ultraviolet rays from the sun. The antarctic ozone hole, as it came to be known, made depletion of. Ozone close to the earth is harmful as it is a major component of smog and affects the function of the. Nearly 90% of earths ozone is in the stratosphere and referred to as the ozone layer. What are the causes and effects of ozone depletion. Ozone layer depletion causes increased uv radiation levels at the earths surface, which is damaging to human health. Presentation on ozone depletion linkedin slideshare. Each year since the late 1970s, much of the protective layer of stratospheric ozone above antarctica has disappeared during september, creating what is. The main effect of ozone depletion is an increase in uvb rays reaching the earths surface. Click any map image to bring up a new page with a highresolution image.
Pdf causes of ozone layer depletion and its effects on. Large seasonal ozone losses occur in polar regions as a result of reactions involving polar stratospheric clouds pscs. The thinning is most pronounced in the polar regions, especially over antarctica. 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. We do these things almost automatically, not really even thinking about it. Assessment for decisionmakers earth system research laboratory. National aeronautics and the ozone hole space administratio n. Ozone depleting substances are the substances such as chlorofluorocarbons, halons, carbon tetrachloride, hydrofluorocarbons, etc. The antarctic ozone hole ozone is a gas made up of three oxygen atoms. Ozone layer depletion leads to decrease in ozone in the stratosphere and increase in ozone present in the lower atmosphere. Global warming is caused by the greenhouse effect, which is essential to life as we know it on planet earth. Tthe ozone hole and global he ozone hole and global global.
The emission of ozone depleting substances has been damaging the ozone layer. Global warming and ozone layer depletion are two different problems see the sidebar misconceptions about global atmospheric change on page 95. Ozone layer depletion cause, effects, and solutions. For the status of the currently ongoing ozone hole, you can visit the copernicus web site.
Ozone hole is created in the region where ozone layer has been depleted. The thinning of the ozone layer is caused by a chemical reaction where man. The term ozone hole refers to a phenomenon observed yearly over the south. Ozone and chlorine monoxide clo, for example, have been observed extensively with a variety of instruments.
The ozone depletion phenomenon the national academies press. Project report on ozone depletion environmental pollution. When the ozone hole was first detected, there was emotional debate in which. Like an infection that grows more and more virulent, the continentsize hole in earths ozone layer keeps getting bigger and bigger. Exposure tests made in usa and australia have showed that over one hundred species of land plant could be sensitive to increases in uvb radiation as a result of stratospheric ozone depletion. The stratosphere is home to the ozone layer that protects life on earth from intense ultraviolet radiation. A close look at the evolution at the life on earth reveals that initially the. Few years ago ozone holes are also discovered in arctic region. Explain in your own words how cfcs damage the ozone layer. Uncovering the hidden hazard of hairspray a usual morning routine might include a spritz of hairspray, a spurt of shaving cream, or a spray of deodorant.
A thinning of the ozone layer also has been observed over other regions of the globe, such. Ozone absorbs a band of ultraviolet radiation called uvb. But through domestic and international action, the ozone layer is healing and should fully recover by about 2065. The greatest risks connected with the depletion of ozone in the stratosphere are ecological. Jan 20, 2010 this yearly occurrence is called the ozone hole. Presence of ozone in the lower atmosphere is considered as a pollutant and a greenhouse gas.
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 holes are first discovered in antarctica in 1970. Cfcs, hcfcs, halons, methyl bromide, carbon tetrachloride, and methyl chloroform. The subtropical ground ozone concentration in northern hemisphere is twice the corresponding region in southern hemisphere 5. Ozone hole ozone hole is created in the region where ozone layer has been depleted. Since india already receives high doses of ultraviolet uvb radiation, and is at the threshold go to speak, effects of ozone layer depletion. In years with a strong polar vortex, the ozone hole is seen to expand in diameter, whereas in years with a weaker polar vortex, the ozone hole is noted to shrink. Most ozone can be found in the upper layer of the earths atmosphere, called the stratosphere, which starts between about 6 and 8 miles and continues to around 30 miles. Effects of ozone depletion for humans and the environment. The thinning or reduction of ozone depletion is most prominent in the polar regions, especially over antarctica.
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