Causes of ozone depletion causes and effects of ozone layer. The term ozone hole refers to the depletion of the protective ozone layer in the upper atmosphere stratosphere over earths polar regions. Factor of ozone depletion human activities in the last several decades have produced chemicals, such as chlorofluorocarbons cfcs. Few years ago ozone holes are also discovered in arctic region. The depletion of the ozone describes two closely related but distinct phenomena which have been repeatedly observed since the latter 1970s. 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. Every year, since at least 1978, there is a sudden, rapid decrease in the stratospheric ozone levels at the end of the antarctic winter. Ozone holes are first discovered in antarctica in 1970. The ozone hole appears over antarctica because meteorological and chemical conditions unique to this region increase the effectiveness of ozone destruction by reactive halogen gases see q8.
To understand low ozone spread in atmosphere, one needs to know the structure and. In 1995, the two chemists shared the nobel prize for chemistry with paul crutzen, a dutch chemist who demonstrated that chemical compounds of nitrogen oxides accelerate the destruction of stratospheric ozone. The ozone layer is a deep blanket in the stratosphere made up of comparatively high concentration of the ozone. These chemicals are found in cleaning agents, aerosols, insulating foam, and refrigerants.
Resent research suggests that the strength of the polar vortex from any given year is directly correlated to the size of the ozone hole. Jan 20, 2010 this yearly occurrence is called the ozone hole. Ozone depletion consists of two related events observed since the late 1970s. When the sunlight returns to the south pole in october, uv light rapidly breaks the bond between the two chlorine atoms, releasing free chlorine into the stratosphere, where it takes part in reactions that destroy ozone molecules while regenerating the. The richness of the ozone layer that makes the hole so significant and the science behind the hole is far less popular. Causes and effects introduction in this section, we will discuss about the ozone hole and its causes what is the ozone hole. The ozone problem is back and worse than ever science.
The term ozone hole is applied when the depletion level is below 200 dobson unit d. 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. The ozone problem is back and worse than ever james anderson, the winner of a smithsonian american ingenuity award, has discovered the alarming link between climate change and ozone loss. Ozone layer and causes, effects and solutions to ozone depletion. Generally, we find thinning or depletion of the ozone layer to the extent of ozone hole creation over the southern pole i. It is revealed that introduction of chloroflourocarbons cfcs in the environment is the most rated cause of said depiction. The ozone layer helps to protect life from harmful ultraviolet radiation.
Why has an ozone hole appeared over antarctica when ozonedepleting. In march 2006, the winds circling high above the arctic allowed nearrecord amounts of ozonedestroying gases. The ozone hole and global warming union of concerned scientists. Soils have recently been identified as a significant sink of.
Much larger decrease in stratospheric ozone is observed around earths polar regions. 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. Feb 12, 2018 far above earths surface, the ozone layer helps to protect life from harmful ultraviolet radiation. Why has an ozone hole appeared over antarctica when ozone. These reactions convert the inactive chlorine reservoir chemicals into more active forms, especially chlorine gas cl 2.
N 2 o, ch 4 and co 2 cooling of the stratosphere has been forecasted leading to low loss of total ozone. Enhancement of the green house effect may also be causing changes in circulation patterns in the troposphere that are. The formation of the ozone holes is different to the generalized ozone depletion effect observed around more equatorial zones where higher concentrations of humans exist. It is revealed that introduction of chlorof lourocarbons cfcs in the environment is the most rated cause of said depiction. The gaping hole in the ozone layer of the atmosphere over the antarctic was caused primarily by high concentrations of ozone depleting chemicals called cfcs. Ozone hole ozone hole is created in the region where ozone layer has been depleted. Considering all other changes in trace gas system e. 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. Learn more about the process, causes, and effects of ozone layer depletion. Ozone hole is created in the region where ozone layer has been depleted. Skin cancer and ultravioletb radiation under the antarctic ozone hole. As explained above, the overall cause of ozone depletion is the. Ozone depletion, ozone hole, ultraviolet radiation. The vast hole in the ozone was discovered by scientists in the 1980s, who upon discovering the dramatic loss in ozone cover, set to work determining a primary cause.
Ozone hole ozone depletion at south pole polar vortex and ozone depletion are two distinct but related phenomena. But it does not cause more than 12% of the ozone layer depletion. What are the principal steps in stratospheric ozone depletion caused by. People, plants, and animals living under the ozone hole are harmed by the solar radiation now reaching the earths surfacewhere it causes health problems, from eye damage to skin. The volcanic eruptions are also responsible for the depletion of. 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.
The ozone layer has been found to be depleted by certain natural processes such as sunspots and stratospheric winds. The causes, mechanism and bioeffects of ozone layer depletion on humans were addressed. The major factors involved in the cause of ozone hole is not known but there are some chlorine and its radicals that are responsible for this. Causes and effects of ozone layer depletion that are. Ozone layer depletion causes, effects and solutions 7. Consequently, the level of ozone protecting us from ultraviolet radiation. Causes, effects and solutions of ozone layer depletion. National aeronautics and the ozone hole space administratio n. There have been several concerns about ozone depletion. This beneficial ozone has been partially destroyed by manmade chemicals, causing what is sometimes called a hole in the ozone. The ozone hole is an area where the amount of ozone in the upper atmosphere is much lower than normal.
Called stratospheric ozone, good ozone occurs naturally in the upper atmosphere, where it forms a protective layer that shields us from the suns harmful ultraviolet rays. Mar 12, 2019 ozone layer depletion is the destruction of ozone gas of upper atmospheric layer stratosphere, caused by substances formed from breakdown of ozone depleting substances ods. 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. This series of satellite images shows the ozone hole on the day of its maximum depth each year from 1979 through 2019. However, various factors have led to the depletion and damage of this protective layer. The ozone hole and global warming union of concerned. 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. But the one and the most important reason for ozone layer depletion is the. The ozone hole was mentioned in newspapers and on tv quite commonly during. Measurements from satellitebased instruments show that this area of very low ozone concentration has developed over antarctica every year since about 1975. The latter phenomenon is referred to as the ozone hole.
Pdf on jan 1, 2001, md safiuddin and others published global ozone 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. There are many causes for ozone depletion, but the most important process in both trends is. There is a steady decline of about 4% in the total volume of ozone in earths stratosphere. The ozone layer thus plays an important role by preventing the harmful uv radiations from penetrating into the earths lower atmosphere the troposphere. The main effect of ozone depletion is an increase in uvb rays reaching the earths surface. 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. Ozone layer depletion is one of the major environmental issues which is getting thinner day by day as a result of increasing pollution. In fact, a major hole in the ozone layer above the antarctica skyline now threatens the continent badly. The severe depletion of stratospheric ozone in late winter and early spring in the antarctic is known as the ozone hole see q11. Ozone depletion and climate change environment canada.
The vast hole in the ozone was discovered by scientists in the 1980s, who upon discovering the dramatic loss in. People, plants, and animals living under the ozone hole are harmed by the solar radiation now reaching the earths surfacewhere it causes health problems, from eye damage to skin cancer. In a similar reaction, o 3 molecules can be broken down into atoms of o and molecules of o 2. Contrary to common misconception, ozone is not in the form of thick layer surrounding atmosphere. Find out what caused the ozone hole, and how the 1989 montreal protocol sought to put an end to ozone depletion. Causes of ozone layer depletion and its effects on human. Apr 18, 2019 the ozone layer helps to protect life from harmful ultraviolet radiation. The gaping hole in the ozone layer of the atmosphere over the antarctic was caused primarily by high concentrations of ozonedepleting chemicals called cfcs. Ozone layer depletion was first identified in late 1970s and the scientists claimed that 4% of the total ozone has been destroying per decade. Why has an ozone hole appeared over antarctica when.
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. The thinning is most pronounced in the polar regions, especially over antarctica. In the measurements made in recent times significant reductions in ozone concentrations in the layer, with special. Jul 16, 2008 the term ozone hole refers to the depletion of the protective ozone layer in the upper atmosphere stratosphere over earths polar regions. The ozone layer is responsible for absorbing harmful ultraviolet rays, and preventing them from entering the earths atmosphere. Jan 07, 2016 ozone hole ozone depletion at south pole polar vortex and ozone depletion are two distinct but related phenomena. The larger holes cause ozone to leak out at a faster rate than ozone is being created. The volcanic eruptions are also responsible for the depletion of ozone layer. Jul 29, 20 ozone layer depletion was first identified in late 1970s and the scientists claimed that 4% of the total ozone has been destroying per decade.
Methyl bromide is the single largest contributor of stratospheric br and an important contributor to stratospheric ozone depletion. Ozone layer depletion is one of the major environmental issues which is getting thinner day by day as a. 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 is an ozone hole and causes and effects of ozone. Causes of ozone depletion ozone depletion occurs when the natural balance between the production and destruction of stratospheric ozone is tipped in favour of destruction. The problems and causes associated with ozone depletion arise from human activities. Ozone layer depletion cause, effects, and solutions. This timeline highlights the average area of the ozone hole between september 7th and october th as observed by nasa spacedbased instruments see. Ozone is naturally created when uv radiation hits oxygen gas molecules o 2 and breaks some of them apart into single oxygen atoms. Ozone layer and causes, effects and solutions to ozone. Ozone hole in some of the popular news media, as well as in many books, the term ozone hole has and often still is used far too loosely. Frequently, the term is employed to describe any episode of ozone depletion, no matter how minor.
Since the discovery of the antarctic ozone hole in the mid1980s, a great deal of scientific attention has focussed on understanding the causes and evolution of the ozone loss in both polar. These single atoms of oxygen then bond with other o 2 gas molecules, forming o 3. Most of ozone is formed at equator where there is maximum sunshine but with winds it travels at high altitude and get accumulated in stratosphere 1. The latest satellite measurement indicates an ozone loss at the rate of 8% just above the south pole, at the centre of the ozone hole, 5% of the protective gas is depleting each day. 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 main things that lead to destruction of the ozone gas in the ozone layer. However, while both the ozone depletion and the ozone hole effects are different they share a common causal process which is thought to be responsible for both. This is due to the chemical reactions that take place primarily on the surface of polar stratospheric clouds, ice particles or liquid droplets which form at.
These chemicals combine with certain weather conditions to cause reactions in the ozone layer, leading to ozone molecules being destroyed. Learn what cfcs are, how they have contributed to the ozone hole, and how the 1989 montreal. There are also springtime polar tropospheric ozone depletion. This is due to the chemical reactions that take place primarily on the surface of polar stratospheric clouds, ice particles or liquid droplets which form at high altitudes in extreme cold. The ozone hole was mentioned in newspapers and on tv quite commonly during the 1980s because the interest of environmental. Equally untrue is another misconception that a hole is made in this ozone layer. Ozone layer depletion essay sample new york essays. There are plenty of causes and effects of ozone depletion, cfc emission being one. Ultra violet rays have the capability to destroy plants and animals and can cause skin. The signs of antarctic ozone hole recovery scientific. It was found that the hole commonly called as antarctic ozone hole, was formed each year after the return of the sun at the end of polar night. The thinning of the ozone layer is caused by a chemical reaction where man. 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 the early 1980s, scientists began to realize that cfcs were creating a thin spota holein the ozone layer over antarctica every spring.
That was an alarming situation for environmentalists all over the world because ozone layer depletion is directly proportional to some of the most destructive skin diseases including tumor formation. The ozone hole is an annual thinning of the ozone layer over antarctica, caused by stratospheric chlorine. The term ozone hole refers to a phenomenon observed yearly over the south. 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. Introduction the earth is protected from excessive ultraviolet rays by an atmospheric ozone layer. Pdf causes of ozone layer depletion and its effects on. Far above earths surface, the ozone layer helps to protect life from harmful ultraviolet radiation. Causes of ozone depletion causes and effects of ozone.
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