The earths stratospheric ozone layer plays a critical role in absorbing ultraviolet radiation emitted by the sun. When cfc is released into the atmosphere, they mix with atmospheric. We provide reading comprehension exercises with answers. Ozone is unstable and decomposes to molecular oxygen. This passage is all about the ozone layer and the ozone layer restricts.
Dec 14, 2017 scientists are closely monitoring positive signs of recovery of the earths stratospheric ozone layer, which is depleted by the use of chemicals called chlorofluorocarbons cfcs for a range of. Questions and answers about the environmental effects of the ozone layer depletion and 4 climate change. 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. By 1985, the globe had already seen advancements in the scientific understanding of ozone depletion and its impacts on human health and the environment. Unfortunately, humanproduced chemicals in our atmosphere such as chlorofluorocarbons c fcs. Unlike pollution, which has many types and causes, ozone. But the one and the most important reason for ozone layer depletion is the production and emission of. This, in turn, will lead to the breakdown of ozone. Sep 30, 2019 what are the causes of the depletion of our ozone layer. Some say anthropogenic carbon dioxide co 2 emissions caused the earth to warm. Ozone is earth s natural sunscreen, shielding life from dangerous solar ultraviolet radiation. Aug 01, 2016 the term ozone depletion means more than just the natural destruction of ozone damage in the ozone layer will naturally mean the entry of harmful rays in to the atmosphere. Nearly 500 organizations, teams, and individuals from 40 countries have received stratospheric ozone protection awards for their exceptional leadership, personal dedication, and technical achievements.
There are many situations where human activities have. Stratospheric ozone depletion, ultraviolet radiation and health. The signs of antarctic ozone hole recovery scientific. If each chlorine atom released from a cfc mol ecule destroyed only one ozone molecule, cfcs would pose very little threat to the ozone layer. It contains high concentration of ozone o 3 in relation to other parts of the atmosphere, although still small in. Pdf on jan 1, 2001, md safiuddin and others published global ozone depletion. He found that cfcs could lead to even more ozone destruction than the natural mechanisms did. Changes in atmospheric ozone amounts and ultraviolet radiation. It was the first international treaty to be signed by all countries of the world and is considered the greatest environmental success story in the history of the united nations. The ozone layer or ozone shield is a region of earth s stratosphere that absorbs most of the sun s ultraviolet radiation. Ozone is formed when the sunlight hits oxygen molecules o 2 and breaks them up into individual atoms.
Ozone depletion is one of several factors, includ ing cloud cover and solar elevation, which affect ground level uv radiation. 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 is an irritating, corrosive, colorless gas with a smell something like burning electrical wiring. Ashworth abstract there has been a lot of discussion about global warming. Pscs form in the ozone layer during winters in the arctic and antarctic stratospheres wherever. The first report of depletion in o 3 layer came out in the 1980s by an atmospheric scientist in antarctica. Interactions between climate change and stratospheric ozone may delay recovery of the ozone layer by 1520 years 5. Depletion of this layer by ozone depleting substances ods will lead to higher uvb levels, which in turn will cause. 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. Apr 18, 2019 the ozone layer helps to protect life from harmful ultraviolet radiation. Cfc destruction of ozone major cause of recent global warming. It occurs mainly in late winter and early spring augustnovember and peak depletion usually occurs in early. Recordsetting ozone hole forms over the north pole due to. In 1987, to address the destruction of the ozone layer, the international community established the montreal protocol on ozone depleting substances.
A combination of low temperatures, elevated chlorine, and bromine concentrations in the upper stratosphere are responsible for the destruction of ozone. Ozone layer depletion is one of the major environmental issues which is getting thinner day by day as a result of increasing pollution. Protection of the ozone layer climate action european commission. Which reactions demonstrate the destruction of the ozone layer. Ozone near the ground is a pollutant, but in the upper stratosphere, it forms a protective layer around the planet that absorbs ultraviolet sunlight, thereby protecting all life from the harmful effects of that radiation. Depletion of ozone layer is also causing the problem of food shortage to humans. Chlorofluorocarbons cfcs have been identified as the main cause of the destruction to the ozone layer, but there are also compounds containing bromine, other halogen compounds and also nitrogen oxides which cause damage. Causes, effects and solutions of ozone layer depletion.
The ozone layer lies approximately 1540 kilometers 1025 miles above the earths surface, in the stratosphere. In humans, a depleted ozone layer would likely mean higher rates of skin cancer, cataracts, and immune system problems. If the rate is substantially lower than previously thought, then it would not be possible to create enough aggressive chlorine radicals to explain the observed ozone losses at high latitudes, says rex. This ozone layer protects us from solar ultraviolet uv radiation. This layer absorbs 9399% of the suns high frequency ultravioletlight, which. Destruction of the ozone layer the ozone layer is a layer in earths atmosphere which contains relatively high concentrations of ozone o3. What are the causes and effects of ozone depletion. Ozone depletion consists of two related events observed since the late 1970s. Stratospheric ozone protection awards since 1990, epa has recognized outstanding achievement in ozone layer protection. Scientists first began to realize the potential for chlorine to interact destructively with ozone in the early 1970s, and sherwood rowland and mario molina warned of the danger. The thinning is most pronounced in the polar regions, especially over antarctica. This pho tograph of an arctic polar stratospheric cloud psc was taken from the ground at kiruna, sweden 67n, on 27 january 2000.
Stratospheric ozone depletion, ultraviolet radiation and. Unfortunately, this gives them plenty of time to find their way to the ozone layer. Ozone layer destruction of the ozone layer the causes. Apr 19, 2018 the rapid photolysis of cl2o2 is a key reaction in the chemical model of ozone destruction developed 20 years ago2 see graphic. Polar stratospheric clouds and ozone depletion pdf. Scientists are closely monitoring positive signs of recovery of the earths stratospheric ozone layer, which is depleted by the use of chemicals called chlorofluorocarbons cfcs for a. It has been found that this protective ozone layer is getting depleted because of the presence of cfc chlorofluorocarbon compounds. This layer absorbs 9399% of the suns high frequency ultravioletlight, which is potentially damaging to life on earth. Meaning, pronunciation, translations and examples log in dictionary. Frequently asked questions about the ozone layer ozone.
Find out what caused the ozone hole, and how the 1989 montreal protocol sought to put an end to ozone depletion. The ozone layer destruction is the decrease in the amount of ozone found in the terrestrial stratosphere specifically in the ozone layer due to the release of gases such as halocarbon refrigerants, solvents, propellants and foaming agents such as cfcs, freons and alons the ozone layer is a part of the stratosphere whose main component is ozone, a substance that has 3 molecules of oxygen. Feb 12, 2018 far above earths surface, the ozone layer helps to protect life from harmful ultraviolet radiation. Ozone depletion is primarily caused by human activities. The initial step in the depletion of stratospheric ozone by human activities is the emission of ozone depleting. Ozone is a triatomic form of oxygen o 3, found in the earths atmosphere. Ozone depletion and climate change environment canada. The latest ozone layer depletion news is included at the foot of the page. Cfc destruction of ozone major cause of recent global. Destruction definition and meaning collins english. The vienna convention for the protection of the ozone layer. Our results demonstrate that the montreal protocol has indeed begun to save the antarctic ozone layer.
One chlorine atom can break apart more than 100,000 ozone molecules. The earths ozone layer ozone layerthe region of the stratosphere containing the bulk of atmospheric ozone. These chemicals are found in cleaning agents, aerosols, insulating foam, and refrigerants. Basic ozone layer science ozone layer protection us epa. The ozone layer is a deep blanket in the stratosphere made up of comparatively high concentration of the ozone. 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. Questions and answers about the environmental effects of the. The ozone layer is a concentration of ozone molecules in the stratosphere. During the 1970s, humanproduced chemicals known as ozone depleting substances, mainly chlorofluorocarbons, were rapidly depleting the ozone layer. Approximately 90 percent of the atmospheres ozone occurs from 1018 km 611 miles to about 50 km about 30 miles above earths surface. In this photograph, the two lowest layers of the atmosphere, the troposphere and the stratosphere, are clearly visible.
Frederick, in encyclopedia of atmospheric sciences second edition, 2015. Without human intervention, the stratospheric ozone layer would be produced and destroyed through natural processes. 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. Essay on ozone depletion and the environment 1505 words 7 pages. It was the first international treaty to be signed by all countries of the world and is considered the greatest environmental success story in. Reading skills get sharpened by unseen passage reading comprehension test.
There are also springtime polar tropospheric ozone depletion. According to t he chemical model fo r ozone destruction pr oposed about 20. Pdf causes of ozone layer depletion and its effects on. It is an essential factor for many global, biological and environmental phenomena. Causes of ozone layer depletion and its effects on human. Oxygen can combine into molecules with three atoms, however, which are called ozone. Further, that loss of ozone itself augments the cooling of the stratosphere. What is the chemical reaction that displays how ozone is created. However, in the arctic, its rare to get conditions that are primed for ozone destruction over long periods of time.
Ozone layer depletion cause, effects, and solutions. Ozone layer depletion is the thinning of the ozone layer present in the atmosphere. 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. Concerns over depletion of the ozone layer arose in the 1970s, when scientists realized that chemicals released by various anthropogenic activities could lead to a slow decline in ozone amounts in the stratosphere. Destruction is the act of destroying something, or the state of being destroyed. Learn what cfcs are, how they have contributed to the ozone hole, and how the 1989 montreal. Third, depletion of stratospheric ozone and global warming due to the build. The ozone layer helps to protect life from harmful ultraviolet radiation. Ozone layer depletion is one of the major environmental issues which is getting thinner day by day as a. The production and emission of chlorofluorocarbons cfcs, is the leading cause of ozone layer depletion.
The amounts of ozone in the stratosphere vary naturally throughout the year as a result of production and destruction processes, and as a result of winds and other transport processes that. Approximately 90 percent of the atmospheres ozone occurs from 1018 km 611 miles to. Cfc molecules are highly stable and can last for up to 100 years. The main things that lead to destruction of the ozone gas in the ozone layer. Twenty questions and answers about the ozone layer. These individual atoms then join up with o 2 molecules and make o 3, or ozone. Uv radiations are disturbing developmental and physiological processes which is decreasing the productivity of crops. Ozone layer depletion causes, effects and solutions 7. Ozone layer depletion is the gradual thinning of the earths ozone layer in the upper atmosphere caused due tho release of chemical compounds containing gaseous bromine or chlorine from industries or other human activities. Ozone o3 is a stratospheric layer that plays important role in providing support to humans for their survival. We cant make enough ozone to replace whats been destroyed, but provided that we stop producing ozonedepleting substances, natural ozone production reactions should return the ozone layer to normal levels by about 2050. Aug 07, 2018 the ozone with chemical formula o3 is a molecule composed of three atoms of oxygen, reason why it is also known as trioxygen.
Hence, cfcs are transporting agents that are responsible for damaging the ozone layer. It forms a natural belt or shield in the upper atmosphere at 20 km to 30 km above earth, also called stratosphere. Timeline of stratospheric ozone depletion and observations. 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 there are many situations where human activities have significant effects on the environment. There are a number of chemical reactions that can deplete stratospheric ozone. The word ozone means smelly in greek because the gas has a strong odor. 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. The hole story about earth s ozone hole through the years 1970 2011. The ozone layer is expected to return to normal levels by about 2050. Ozone is a gas made up of molecules that are formed by three oxygen atoms. Are recent arctic ozone losses caused by increasing.
Ozone layer introduction the ozone layer refers to the ozone within stratosphere, where over 90% of the earths ozone resides. But, it is very important that the world comply with the montreal protocol. What are the principal steps in stratospheric ozone depletion caused by human activities. The latter phenomenon is referred to as the ozone hole. Causes of ozone depletion ozone layer depletion, is simply the wearing out reduction of the amount of ozone in the stratosphere. Questions and answers about the environmental effects of the ozone layer depletion and. In 1987, governments of the world came together and crafted the united nations montreal protocol as a global attempt to address this issue. Or decrease in stratospheric ozone around earths polar region this phenomena is referred as ozone hole. In the last thirty years, it has been discovered that stratospheric ozone is depleting as a result of anthropogenic pollutants. Notably, the montreal protocol and its amendments have led to a signi.
This is because the polar vortex often wobbles offkilter or breaks down. One chlorine molecule from a cfc can destroy up to 100,000 ozone molecules. A dynamic equilibrium is maintained between the formation and decomposition of ozone. If each chlorine atom released from a cfc molecule destroyed only one ozone molecule, cfcs would pose very little threat to the ozone layer. Causes and effects of ozone layer depletion that are. When did we realize ozone depletion was an issue, and how did we fix it.