Layers of the atmosphere 45the suns utraviolet rays 68the ozone layer 9 3 4. 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. 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 layer depletion is one of them. Impacts of acidification and climate change are also combining to cause dra.
The human released chlorofluorocarbons are the main and primary causes to destroy ozone layer. Causes of ozone layer depletion the main things that lead to destruction of the ozone gas in the ozone layer. Fire extinguishers contain halons and methyl bromide in the form of pesticides can also be also a cause for the depletion. Ozone depletion is primarily caused by human activities. There are many situations where human activities have. However, near the surface where we live and breathe, ozone is a harmful pollutant that causes. Unlike pollution, which has many types and causes, ozone depletion has been pinned down to one major human activity. This website addresses stratospheric ozone issues, including the science of ozone depletion, epas regulatory approach to protecting the ozone layer, epa. The main effect of ozone depletion is an increase in uvb rays reaching the earths surface causes. It is revealed that introduction of chloroflourocarbons cfcs in the environment is the most rated cause of said depiction.
You can find maps of the ozone layer and compare different regions of the globe for ozone coverage. One of the main reasons for the widespread concern about depletion of the ozone layer is the anticipated increase in. It contains high concentrations of ozone o3 relative to other parts of the atmosphere. There have been several concerns about ozone depletion. Found in industrial solvents, drycleaning agents and hospital sterilants. No one knows for certain how much more ozone depletion will occur.
Although natural phenomena can cause temporary ozone loss, chlorine and bromine released from manmade compounds such as cfcs are now accepted as the main cause of this. Thus, ozone layer depletion has become a major concern among the environmentalists. As a result more solar uvb radiation 290320 nm reaches to the surface. It is an essential factor for many global, biological and environmental phenomena. 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. The ozone layer refers to a region of earths stratosphere that absorbs most of the suns uv radiation. There are important effects of changes in the intensity of solar uv radiation resulting from stratospheric ozone depletion, particularly uvb. Environmental effects of ozone depletion, uv radiation and interactions with climate change. There are also springtime polar tropospheric ozone depletion. What are the causes and effects of ozone depletion. Ozone o3 is present in 1 ppm in the upper stratosphere, and it absorbs virtually all of the uv radiation from the sun. Layers of the atmospherethe atmosphere is divided into five layers.
Ozone depletion facts and information national geographic. Protecting the ozone layer department of the environment. Depletion of ozone definition of depletion of ozone by. Ozone layer depletion essay sample new york essays.
Pdf ozone o 3 is a stratospheric layer that plays important role in providing. Causes of ozone layer depletion and its effects on human. Many of them can persist in the stratosphere for centuries. 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.
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. The fact sheet series is aimed at students involved in key stage 4 of the national. Ozone depletion occurs when the natural balance between the production and destruction of stratospheric ozone is tipped in favour of destruction. Ashes can stay in the stratosphere for about two to five years, and within. This can be harmful to skin, and, thankfully, the ozone protects us from much of it. The ozone layer prevents all uvc from reaching the earths surface. Although natural phenomenon can cause ozone depletion but human activities such as cfcs are now accepted as major cause of depletion 9. Ozone depletion describes two distinct but related phenomena observed since the late 1970s. Both come from the breaking down of chloroflourocarbons freons by photons in the atmosphere. 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.
Ozone depletion causes increases in uv rayss effects on aquatic ecosystems by. The ozone layer is important for blocking most of the harmful radiation that comes from the sun. The ozone layer is a region of the stratosphere containing ozone, or o3 gas. The problems and causes associated with ozone depletion arise from human activities. The ozone layer helps to protect life from harmful ultraviolet radiation. All ozone depleting chemicals contain chlorine and bromine 10. Industries that manufacture things like insulating foams, solvents, soaps, cooling things like air conditioners. It takes years for cfcs and other ozonedepleting compounds to reach the stratosphere. Photochemical processes are the principal causes of ozone depletion in the stratosphere.
Find out what caused the ozone hole, and how the 1989 montreal protocol sought to put an end to ozone depletion. Ozone does not absorb uva light uvb between 280 and 320 nanometers. Ozone layer depletion, its causes and its effects scribd. The ozone layer protects us from excessive levels of harmful ultraviolet uv radiation. The latest ozone layer depletion news is included at the foot of the page. Is there a difference in ozone coverage between different hemispheres. These models work by combining satellite measurements of. These gaseous pollutants react with the ozone to produce oxygen by which the net result is the depletion of ozone. Factor of ozone depletion human activities in the last several decades have produced chemicals, such as chlorofluorocarbons cfcs. Unep environmental effects assessment panel, update 2017.
But even a healthy, thick ozone layer doesnt prevent all uvb from reaching the earth. Used as coolants in refrigerators, freezers and air conditioners in buildings and cars manufactured before 1995. The clo molecules combine with each other, forming a com. The exposure to these radiations is severely affecting all life forms on earth.
The ozone layer and its depletion linkedin slideshare. Cause of ozone depletion the depletion of ozone in the stratosphere by the number of gaseous pollutants like nitric oxide no, nitrous oxide n 2 o, chlorine cl, chlorofluorocarbons cfcs etc. What are the principal steps in stratospheric ozone depletion caused by human activities. 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. In fact, a major hole in the ozone layer above the antarctica skyline now threatens the continent badly. Chlorofluorocarbons or the cfc are the main cause of ozone layer depletion. How severe is the depletion of the antarctic ozone layer.
The ozone layer depletion is a major concern and is associated with a number of factors. Learn more about the process, causes, and effects of ozone layer depletion. The ozone layer is mainly found in the lower portion of the stratosphere. Ozone depletion potential an overview sciencedirect topics. There are plenty of causes and effects of ozone depletion, cfc emission being one. Ozone depletion occurs when the natural balance between the production and destruction of stratospheric ozone is disturbed. The ozone layer thus plays an important role by preventing the harmful uv radiations from penetrating into the earths lower atmosphere the troposphere. As a result, there has been a general thinning of the ozone layer over most of the globe, including between five to nine per cent depletion over australia since the 1960s. 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 is simply the wearing out reduction of the amount of ozone in the stratosphere. Ozone o3 is a stratospheric layer that plays important role in providing support to humans for their survival. Causes of ozone depletion there are two different types of ozone depletion, both are very similar. Unlike pollution which has several causes, there is one specific chemical compound that is responsible for the breakdown of the ozone layer. Twenty questions and answers about the ozone layer.
There are many causes for ozone depletion, but the most important process in both trends is catalytic destruction of ozone by atomic chlorine and bromine. But through domestic and international action, the ozone layer is healing and should fully recover by about 2065. These chemicals are found in cleaning agents, aerosols, insulating foam, and refrigerants. The so 2f 2 global background mixing ratio increased during recent decades and had reached about 1. Rivm report 481505011 technical report on stratospheric ozone. Ozone layer depletion cause, effects, and solutions. Causes and effects of ozone layer depletion that are. The ozone layer is responsible for absorbing harmful ultraviolet rays, and preventing them from entering the earths atmosphere.
The effect of atmospheric ozone depletion on environment. Ozone layer depletion causes, effects and solutions 7. Chlorofluorocarbons ozone depletion occurs when the natural balance between the production and destruction of stratospheric ozone is disturbed. Pdf thinning of antarctic ozone layer during spring season has been observed since 1980s, largest depletion occurred during the period. Ozone depletion is allowing the uv radiation to earth surface. Essay ozone depletion is a serious problem presently facing the world. Ozone in the stratospherea layer of the atmosphere between 15 and 50. The main causes responsible for the depletion of the ozone layer are listed below. The ozone layer was discovered in 19 by the french physicists charles fabry and henri buisson.
The initial step in the depletion of stratospheric ozone by human activities is the emission, at earths surface, of ozonedepleting gases containing chlorine and bromine. The concept of ozone depletion potential odp is widely used wuebbles et al. Causes, effects and solutions of ozone layer depletion. The thinning of the ozone layer has increased the risk that australians already face from overexposure to.
It is thickestnear the surface and thins out with height until iteventually merges with space. Hii,the ozone in the ozone layer is being broken down by chlorine atoms from chlorofluorocarbon cfc molecules and bromine atoms from halons. The first one has been a slow, but steady ozone depletion of 4% per decade of the earths. Ozone is destroyed in photochemical reactions with ozone depleting substances. Progress report 2003 united nations environment programme, environmental e. One of the main reasons for the widespread concern about. The thinning is most pronounced in the polar regions, especially over antarctica. Unlike global warming, however, ozone depletion has actually been successfully controlled by international cooperation, perhaps providing a model for other efforts at global environmental protection.
What is the impact of volcanic ash on the ozone layer. The main ozonedepleting substances ods chlorofluorocarbons cfcs the most widely used ods, accounting for over 80% of total stratospheric ozone depletion. The latter phenomenon is referred to as the ozone hole. When volcanoes erupt, they produce massive clouds of ashes into the troposphere, and then they drift upward into the stratosphere the upper atmosphere layer where ozone gas protects humans from uv radiation. The emission of ozone depleting substances has been damaging the ozone layer. Yes, an international consensus about the causes and effects of ozone depletion has emerged.
These ashes contain high concentration of bromine and chlorine. However, various factors have led to the depletion and damage of this protective layer. The causes, mechanism and bioeffects of ozone layer depletion on humans were addressed. Pdf depletion of the ozone layer and its consequences. Frequently asked questions about the ozone layer ozone. The chlorofluorocarbon and the halons are potent ozone depletors. Ozone is an invisible, poisonous gas molecule o 3 that exists in trace minimal amounts in the stratosphere 630 miles above the earth. Pdf causes of ozone layer depletion and its effects on. The danger and prevention of ozone layer depletion. Money and time are being spent on ozone repair, but the problem still exists. This uv radiation destroys dna and proteins in all living organisms.
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