If each chlorine atom released from a cfc molecule destroyed only one ozone molecule, cfcs would pose very little threat to the ozone layer. Questions and answers about the environmental effects of. Experts blame ozone layer depletion on manmade chem icals containing. The montreal protocol on the protection of the global ozone layer is a somewhat unique example of how the world can respond when faced with a serious environmental threat. Montreal protocol on substances that deplete the ozone layer. Ozone depletion, gradual thinning of earths ozone layer caused by the release of chemical compounds containing gaseous chlorine or bromine from industry. Ozone depletion, depletion, gradual thinning of earths ozone layer in the upper atmosphere caused by the release of chemical compounds containing gaseous chlorine or bromine from industry and other human activities. 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. Ozone molecules have a relatively low abundance in the atmosphere. Stratospheric ozone depletion noaa earth system research. This comprehensive handbook outlines all amendments and decisions. Uv rays can cause sunburn and damage the dna, the ozone layer absorbs most.
Ozone secretariat the secretariat for the vienna convention for the protection of the ozone layer and for the montreal protocol on substances that deplete the ozone layer united nations environment programme nairobi, kenya ozone. Adverse effects means changes in the physical environment or biota, including changes in climate, which have significant deleterious effects on human health or on the composition. The ozone layer is not a layer, it is natural gas in a region called the stratosphere, where ozone particles are scattered between 19 and30 kilometers andelin and john, 1988. It takes years for cfcs and other ozone depleting compounds to reach the stratosphere. Ozone layer depletion is the thinning of the ozone layer that protects the earth from the harmful uv radiations. But our atmosphere is still vulnerable, and it is not clear whether the ozone layer of the future will look like the ozone layer we had in the past.
The ozone layer is found in the lower portion of the earths atmosphere. It has the potential to absorb around 9799% of the harmful ultraviolet radiations coming from the sun that can damage life on earth. The stratosphere gets its name because it is stratified, or layered. Ozone in the stratospherea layer of the atmosphere between 15 and 50 kilometers 10 and 31 miles above usacts as a shield to protect earths surface from the suns harmful ultravio let radiation. The ozone layer, situated in the stratosphere about 15 to 30 km above the earths surface. The troposphere is the layer where most weather activity takes place. Stratospheric ozone as shown in the figure to the right, the stratosphere is the layer of atmosphere above the troposphere. Ozone depletion consists of two related events observed since the late 1970s. Without ozone, the suns intense uv radiation would sterilize the earths surface. We seem to have avoided a future where there is no protective ozone. The exposure to these radiations is severely affecting all life forms on earth. Ozone depletion occurs when the natural balance between the production and destruction of ozone in the stratosphere is tipped in favor of destruction.
The 1974 rowlandmolina hypothesis was that cfcs in the stratosphere when bombarded by uv radiation. The ozone layer, made up of three types of oxygen atoms, is located approximately 15 kilometres above the earth and helps to protect the planet from ultraviolet rays that cause skin cancer, crop. The concentration of ozone in the ozone layer is usually under 10 parts ozone per million. The stratospheric ozone layer forms a thin shield in the upper atmosphere, protecting life on earth from the suns ultraviolet uv rays. We simulated a world avoided, and its a world we should be glad we avoided, newman said. The ozone layer is a layer in earths atmosphere which contains relatively high concentrations of ozone o 3. The latter phenomenon is referred to as the ozone hole. Ozone depletion, depletion, gradual thinning of earths ozone layer in the upper atmosphere caused by the release. Aware that meaeures taken to protect the ozone layer from depletion ahould be baaed on relevant ecientific knowledge, taking into account teclmical and economic conaiderationa, deterained to protect the ozone layer by taking precautionary aea1ure1 to. Canadas involvement in ozone research and monitoring reflects our special concern as a northern polar nation over the fate of the arctic ozone layer. Within a few days, the damaged cells are replaced and the old. In the 1980s, scientists found evidence that the ozone layer was being depleted. The vienna convention for the protection of the ozone layer.
Approximately 90% ozone is present in stratosphere at the height of 10 to 17 kilometer and is called ozone layer while remaining 10% is present in troposphere 3. Ozone can inflame and damage the lining of the lung some scientists have compared ozone caused lung damage to a sunburn. Causes of ozone layer depletion and its effects on human. Although the stratospheric ozone layer still bears the impacts of ozone depleting. In the stratosphere near the peak of the ozone layer, there. Ozone holes are popular names for areas of damage to the ozone layer. Many of them can persist in the stratosphere for centuries. The effort to protect the earths ozone layer has been the first occasion where. The ozone layer is on track to completely repair itself in.
The ozone layer helps in absorbing the ultraviolet uv rays of the sun which are harmful to human beings. In fact, the 1995 nobel prize in chemistry was awarded to three scientists who revealed the role of manmade chemicals, chlorofluorocarbons, or cfcs, in the ozone depletion process. Increased depletion has recently started occurring over the arctic as well. The concern over exposure to biologically harmful levels of uv radiation has been the main driver of the creation of international treaties such as the montreal protocol on substances that deplete the ozone layer and its amendments, designed to protect earths ozone layer. If there were to be additional production of cfcs at, for example, 20% of 1992 levels for each year through 2002 and ramped to zero by 2005 beyond that allowed for countries operating under article 5 of the montreal protocol, then the integrat. 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. Stratospheric ozone depletion, ultraviolet radiation and.
However, the ozone layer is destroyed by manmade chemicals known as ozone depleting substances ods. Prolonged exposure to uvb radiation is linked to skin cancer, genetic damage and immune system suppression in humans and animals, and lower. Pdf there are many situations where human activities have significant effects on the environment. The problem of ozone depletion is there an international. The ozone layer protects earth from dangerous uv radiation fig. A way of contaminating substances from the troposphere into the stratosphere is by no means simple. National aeronautics and the ozone hole space administratio n. In 1977 the united nations environment programme unep concluded a world plan of action on the ozone layer, which called for intensive international research and monitoring of the ozone layer, and in 1981, uneps governing council authorized unep to draft a global framework convention on stratospheric ozone protection. The montreal protocol on substances that deplete the ozone layer is the most successful global environmental agreement in history. The stratosphere is the mass of protective gases clinging to our planet. The thinning is most pronounced in the polar regions, especially over antarctica. Pdf causes of ozone layer depletion and its effects on human. Ozone depletioncauses and effects midnapore college. Protection of the ozone layer, it is the most universally ratified multilateral environmental agreement.
Convention means the vienna convention for the protection of the ozone layer, adopted on 22 march 1985. The manner in which the arctic ozone layer evolves in the future will depend not only on the elimination of ozone depleting chemicals, but also on the control of greenhouse gases and other pollutants. A thinning of the ozone layer also has been observed over other regions of the globe, such as the arctic and northern and southern midlatitudes. Ozone protects living organisms by absorbing harmful ultraviolet radiation uvb from the sun. The emission of ozone depleting substances has been damaging the ozone layer. But through domestic and international action, the ozone layer is. The ozone layer is not really a layer at all, but has become known as such because most ozone particles are scattered between 19 and 30 km 12 to 30 miles up in the earths atmosphere, in a region called the stratosphere. In the 1970s, people all over the world started realizing that the ozone layer was getting thinner and that this was a bad thing. But through domestic and international action, the ozone layer is healing and should fully recover by about 2065. Ozone depletion is one of several factors, includ ing cloud cover and solar elevation, which affect ground level uv radiation. Over 91% of the ozone in earths atmosphere is present here. There are also springtime polar tropospheric ozone depletion. Ozone layer definition is an atmospheric layer at heights of about 20 to 30 miles 32 to 48 kilometers that is normally characterized by high ozone content which blocks most solar ultraviolet radiation from entry into the lower atmosphere. Although the stratospheric ozone layer still bears the impacts of ozone depleting substances.
The ozone layer is very beneficial because it prevents harmful ultraviolet radiation from reaching on earths surface. If the ozone layer was absent, millions of people would develop skin diseases and may have weakened immune systems. The stratosphere is home to the ozone layer that protects life on earth from intense ultraviolet radiation. Life is protected from uv rays by stratospheric ozone layer which acts as a shield or sun screen 2. The loss in this region is commonly called the ozone hole because the ozone depletion is so large and local ized. Ozone layer definition of ozone layer by merriamwebster. Ozone layer damage is more like a really thin patch than a hole. Ozone o 3 is a molecule made up of three atoms of oxygen o, and is mostly found in the strato sphere, where it protects us from the suns harmful ultraviolet uv radiation. Questions and answers about the environmental effects of the ozone layer depletion and. Ozone depletion is the term commonly used to describe the thinning of the ozone layer in the stratosphere. Depletion of the ozone layer results in increased uv. In humans, a depleted ozone layer would likely mean higher rates of skin cancer, cataracts, and immune system problems. He and rowland formed a hypothesis about their fate, which suggested that cfcs would deplete the ozone layer.
Chapte r ozone depletion potentials, global warming. The ozone layer is one layer of the stratosphere, the second layer of the earths atmosphere. The stratospheric ozone layer is earths sunscreen protecting living things from too much ultraviolet radiation from the sun. This layer absorbs 9399% of the suns high frequency ultraviolet light, which is potentially damaging to life on earth. The remaining ozone, about 10%, is found in the troposphere, which is the lowest region of the atmosphere, between earths surface and the stratosphere. Health hazards and control methods guidance note eh38. It wasestablished that, ozone hole has occurred in the ozone layer over antarctica. Ozone layer and the formation of the ozone hole aa. Ozone layer depletion cause, effects, and solutions. The ozone layer or ozone shield is a region of earths stratosphere that absorbs most of the. It will take generations before we know how the experiment turned out. Phasing out hcfc refrigerants to protect the ozone layer. Emissions of certain synthetic chemicalsincluding cfcs, halons, and hcfcsdestroy the ozone layer, and have created an ozone hole over the south pole.
On june 30, 1975 a du pont advertisement in the new york times read. Feb 12, 2021 ozone depletion, gradual thinning of earths ozone layer caused by the release of chemical compounds containing gaseous chlorine or bromine from industry and other human activities. It covers the entire planet and protects life on earth by absorbing harmful ultravioletb uvb radiation from the sun. Ozone depletion is allowing the uv radiation to earth surface. The stratosphere increases in warmth with elevation because ozone gases in the upper layers absorb. The ozone layer is being destroyed by cfcs and other substances. No one knows for certain how much more ozone depletion will occur. Approximately 90 percent of the atmospheres ozone occurs from 1018 km 611 miles to about 50 km about 30 miles above earths surface. The ozone layer is a natural layer of gas in the upper atmosphere that protects humans and other living things from harmful ultraviolet uv radiation.
Low concentrations of ozone have a significant effect upon textiles, fabrics, organic dyes, metals, plastics and paints and cause the characteristic cracking of stressed rubber, commonly called weathering. 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. The response to the ozone crisis by dupont, the inventor of cfcs and the largest producer of ozone depleting chemicals in the world is a prime example of the 3d corporate strategy. Ozone depletion progressing globally except in the tropical zone. The laws of atmospheric dynamics are that the transport of. Ozone layer, region of the upper atmosphere, between roughly 15 and 35 km 9 and 22 miles above earths surface, containing relatively high concentrations of ozone molecules.
Fa il ure to adhere to the international agreements will delay re covery of the ozone layer. Protecting the ozone layer and reducing global warming undp. The ultraviolet rays split the oxygen molecule into free oxygen atoms, these free oxygen atoms combine with the oxygen molecule to form ozone. The top of the thundercloud has flattened out at the tropopause, the. Explore the causes, effects, and solutions to ozone. The ozone layer means the layer of atmospheric ozone above the planetary boundary layer. Ozone damages the cells that line the air spaces in the lung. The ozone layer is found in the upper regions of the stratosphere where it protects the earth from the harmful ultraviolet rays of the sun. Photolysis of atmospheric ozone in the ultraviolet region pdf.
A good idea with a bad outcome the experiments run by newman and. Protecting the ozone layer and reducing global warming. Reports of the ad hoc working group of legal and technical experts for the elaboration of a protocol on chlorofluorocarbons to the vienna convention for the protection of the ozone layer vienna group, unepwg. 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. Uv rays can cause sunburn and damage the dna, the ozone layer absorbs most of the harmful radiations and protects us. Montreal protocol set legally binding controls on the production. Although it represents only a tiny fraction of the atmosphere, ozone is crucial for life on earth. It contains a high concentration of ozone o 3 in relation to other parts of the atmosphere, although still small in relation to other gases in the stratosphere.
Remember, the ozone chemical is the same, but where it is located determines if it is beneficial or a pollutant. Since the ozone layer absorbs uvb ultraviolet light from the sun, ozone layer depletion increases surface uvb levels all else equal, which could lead to damage, including an increase in skin cancer. The montreal protocolthe regime designed to protect the stratospheric ozone layer has widely been hailed as the gold standard of global environmental governance and is one of few examples of international institutional cooperative arrangements successfully solving complex transnational problems. Ozone layer depletion cause, effects, and solutions byjus. Protecting the ozone layer department of the environment. The ozone layer or ozone shield is a region of earth s stratosphere that absorbs most of the sun s ultraviolet radiation.
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