Aerosols are common, convenient, and harmless, right. Linde strongly advocates the use of refrigerant gases with zero ozone depletion potential and fully supports the phase out of hcfcs. R111, 2 global warming potential 100 year, ipcc 4th assessment report, 2007. It covers the entire planet and protects life on earth by absorbing harmful ultravioletb uvb radiation from the sun. The chlorofluorocarbon and the halons are potent ozone depletors. Downloads scientific assessment of ozone depletion 2018. Researchers indicate that many of the effects of ozone depletion on human health tend to apply for animals, too. When there was no ozone layer, life could only exist in the sea. In fact, the ozone depletion was far worse than molina and. The emission of ozonedepleting gases are threatening the earths ozone layer. The ozone layer or ozone shield is a region of earths stratosphere that absorbs most of the. Ozone depletion facts and information national geographic. The stratospheric ozone layer helps filter the suns harmful ultraviolet uv radiation from the earth.
Update on ozone depleting substances odss and other gases of interest to the montreal protocol. Within the stratosphere, the ozone layer is the portion that contains the highest. Prolonged exposure to uvb radiation is linked to skin cancer, genetic damage and immune system suppression in humans and animals, and lower. The ozone layer helps to protect life from harmful ultraviolet radiation. Wmo world meteorological organization, scientific assessment of ozone depletion.
Pdf causes of ozone layer depletion and its effects on. Stratospheric ozone depletion, ultraviolet radiation and health. In 1987, leaders from many countries came together to sign a landmark environmental treaty, the montreal protocol on substances that deplete the ozone layer. This idea connects two issues global warming and depletion of ozone in the upper atmosphere inappropriately, which diverts attention from the main cause of global warming.
Exhaust from a large fleet of these highflying aircraft, it was argued, could conceivably cause severe depletion, with dire consequences, particularly an 3 richard benedick, ozone diplomacy cambridge, mass harvard university press, 1991, p. As our scientific knowledge about ozone depletion grew, so too did the response to the issue. Effects of ozone depletion ozone depletion is affecting the human health and environment negatively, as it allows the penetration of uv radiations to reach the earth. The assessment documents the advances in scientific understanding of ozone depletion reflecting the. Pdf download files stratospheric ozone depletion, ultraviolet radiation and health pdf 107kb pdf files for other chapters and for the complete summary. The latter phenomenon is referred to as the ozone hole. Increased depletion has recently started occurring over the arctic as well. Scientific assessment of ozone depletion montreal protocol. Later this hydroxyl group reacts with the ozone and produce oxygen and water. We do these things almost automatically, not really even thinking about it. Efficient, nontoxic, nonflammable early chemical refrigerants. Stratospheric ozone depletion, ultraviolet radiation and health pdf, 107kb.
The stratospheric ozone layer forms a thin shield in the upper atmosphere, protecting life on earth from the suns ultraviolet uv rays. Who climate change and human health risks and responses. Ozone hole the ozone hole is defined as the area having less than 220 dobson units du of ozone in the overhead column i. Pdf there are many situations where human activities have significant effects on the environment. Like an infection that grows more and more virulent, the continentsize hole in earths ozone layer keeps getting bigger and bigger. Depletion of the ozone layer occurs globally, however, the severe depletion of the ozone layer over the antarctic is often referred to as the ozone hole. The questions address the nature of atmospheric ozone, the chemicals that cause ozone depletion, how global and polar ozone depletion occur, and what could lie ahead for 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. Ozone o3 is a stratospheric layer that plays important role in providing support to humans for their survival. It was originally thought that an ozone hole only existed above antarctica. 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 ozone depletion phenomenon the national academies press. Update on ozonedepleting substances odss and other gases of. There are many situations where human activities have.
To the point where a seasonal hole in the ozone layer began to appear above the antarctic. Protecting the ozone layer department of the environment. The current state of this problem has briefly been considered. Find out what caused the ozone hole, and how the 1989 montreal protocol sought to put an end to ozone depletion. Additional research has shown that ozone depletion occurs over every continent. These radiations can cause severe diseases in humans such as skin cancer, eye damage and genetic mutations etc 9. Apr 18, 2019 the ozone layer helps to protect life from harmful ultraviolet radiation. But many researchers do not agree with these predictions,14 and express their. At the end of 20, 258 projects have been committed for an. The assessment documents the advances in scientific understanding of ozone depletion reflecting the thinking of the many international scientific experts who. 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. Pdf on jan 1, 2001, md safiuddin and others published global ozone depletion. Ozone depleting substances used as solvents class i substances odpa class ii substances odpa cfc1 0.
Ozone depletion consists of two related events observed since the late 1970s. Ozone layer depletion increases the amount of ultraviolet uv irradiation that. The stratospheric ozone layer forms a thin shield in the upper atmosphere, protecting life on earth from. Global warming and ozone layer depletion are two different problems see the sidebar misconceptions about global atmospheric change on page 95. Ozone depleting substances, such as cfcs and hcfcs hydrochlorofluorocarbons, tend not decompose chemically. Oct 27, 2017 the effects of ozone depletion on plants and animals massive amounts of uvb radiation that penetrate our atmosphere do not only affect humans, but also animals and plants. Pdf files for other chapters and for the complete summary. Human activity is the major factor in tipping that natural balance, mostly from releasing artificial chemicals, known as ozone depleting substances ods, to the atmosphere. Quiz questions relating to this section may be found on page 17. Photolysis of atmospheric ozone in the ultraviolet region pdf. There are important effects of changes in the intensity of solar uv radiation resulting from stratospheric ozone depletion, particularly uvb. About depletion of the ozone layer is the anticipated increase in the amounts of.
Firstly, the water molecule reacts with the nascent oxygen to form a hydroxyl group. Complete 2018 scientific assessment of ozone depletion cover, contents, executive summary. Ozone depletion occurs when the natural balance between the production and destruction of ozone in the stratosphere is tipped in favor of destruction. The ozone hole is a sudden, marked depletion of ozone a loss of 50% or more of total column ozone in the lower stratosphere of the. Tthe ozone hole and global he ozone hole and global global. Ozone depleting substances are the substances such as chlorofluorocarbons, halons, carbon tetrachloride, hydrofluorocarbons, etc. Ozone layer depletion compounds that contain chlorine and bromine. Ozone depletion biology science fair project ideas. Another misconception is that ozone layer depletion causes global warming by letting in extra solar radiation. Following is the list of some of the main ozone depleting substances and the sources from where they are released. Low gwp toxic, flammable exposure to toxic gas gas poisoning ozone depletion increasing uv radiation skin cancer crop. The thinning is most pronounced in the polar regions, especially over antarctica. Odp is a relative value of the ozone destructive potential of a chemical substance by unit weight emitted into atmosphere, with the unit weight of cfc11 as 1.
The buildup of oxygen in the atmosphere led to the formation of the ozone layer in the upper atmosphere or stratosphere. Estimates of ozone depletion and skin cancer incidence to examine the vienna convention achievements. Ozone depletion is usually worse further from the equator. Increased uv radiation harms human health and damages animal and plant life. The hypothesis on the formation of the ozone hole due to the action of some molecules emitted by. Formation of the ozone layer use uv to split oxygen into two free atomic oxygen radicals, and then make ozone. An easy way to remember this is the phrase good up high, bad nearby. Stratospheric ozone is the ozone that is formed in the atmosphere with the rays from the sun as source of energy. Experts blame ozonelayer depletion on manmade chem icals containing chlorine and. Each year since the late 1970s, much of the protective layer of stratospheric ozone above antarctica has disappeared during september, creating what is popularly known as the ozone hole.
The biggest cause for this is the use of substances like freon. Ozone depletion results in an increase of uvb radiation, but the shorter the wavelength, the stronger the increase within the uvb range. Ozone layer depletion cause, effects, and solutions. The treatment by leed of the environmental impact of hvac. The saga of cfcs, ozone depletion, and climate change. What links here related changes upload file special pages permanent. 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. It is an essential factor for many global, biological and environmental phenomena. Global warming is caused by the greenhouse effect, which is essential to life as we know it on planet earth. The world meteorological or ganization wmo, 1995 predicted that the depletion of the ozone layer peaked around 1998 and the layer would slowly recover by 2045 12. Causes of ozone layer depletion and its effects on human. When we speak of ozone depletion and ozone holes it means that the ozone up in the stratosphere produced by the sun in some way has disappeared. But higher up, in the stratosphere, good ozone protects life on earth by absorbing some of the suns uv rays.
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