Twenty questions and answers about the ozone layer. First, it describes the threats posed to the ozone layer by the use of ozone depleting substances and analyzes the main obligations under the vienna convention and the montreal protocol. It was originally thought that an ozone hole only existed above. Global ozone depletion and recovery 4 2 0246 1980 2000 2020 2040 ye ar co lumn oz one d ev iation. Ozone depletion consists of two related events observed since the late 1970s. Timeline of stratospheric ozone depletion and observations. The treaty is structured around several groups of halogenated hydrocarbonsthat deplete stratospheric. The ozone layer is projected to return to pre1980 levels by 2050 to 2075.
Depletion of the stratospheric ozone layer by humanproduced ozone depleting substances has been recognized as a global environmental issue for more than three decades, and the international effort to address the issue via the united nations montreal protocol marked its 20year anniversary in 2007. We care about ozone depletion because a thinner ozone layer allows more uv radiation to reach the earths surface. The treaty was opened for signature on september 16, 1987 and. Moreover, volcanic eruptions may inject materials into the stratosphere that can lead to increased destruction of ozone. Presentations ppt, key, pdf logging in or signing up. The ozone hole in antarctica cool antarctica, pictures. Elashry, thank you for the notification dated 18 october 2001 on the forthcoming gef council meeting 57 december 2001 and the invitation to attend. At the end of 20, 258 projects have been committed for an. Trends in emissions of ozonedepleting substances, ozone. Ozone 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. View the latest status of the ozone layer over the antarctic, with a focus on the ozone hole. But many researchers do not agree with these predictions,14 and express their.
The world health organization was established in 1948 as a. A brief analysis of main achievements and challenges illustrates. It was agreed on 16th september 1987, and entered into force on 1st january 1989. Pdf file why has an ozone hole appeared over antarctica when ozone depleting substances are present.
The ozone depletion resulted in secondary production of an ozone layer near the ground terrestrial ozone layer, which is responsible for adverse effects on plants, humans and environment with. Causes of ozone layer depletion and its effects on human. Download a pdf of the ozone depletion phenomenon by the national research council for free. Data shows that stratospheric concentrations of ozone depleting substances are declining. Environmental studies ozone depletion tutorialspoint. An ebook is one of two file formats that are intended to be used with ereader devices and apps such as amazon kindle or apple ibooks. Ozone layer depletion cause, effects, and solutions. There are many situations where human activities have. The ozone layer is the common term for the high concentration of ozone that is found in the stratosphere around 1530km above the earths surface.
The ozone layer is a layer of gas about 15 km above the earths surface. Click download or read online button to get acid rain and ozone layer depletion book now. Pdf causes of ozone layer depletion and its effects on. The ozone hole in antarctica the seasonal thinning of the ozone layer of the earths atmosphere above antarctica, so allowing abnormal amounts of ultraviolet light to reach the earths surface in those regions. The thinning or reduction of ozone depletion is most prominent in the polar regions, especially over antarctica.
This site is like a library, use search box in the widget to get ebook that you want. Cfcs has led to a magnified springtime depletion of the protective ozone layer at both earths poles, especially over antarctica, a phenomenon well known as the ozone hole. 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 kilometers 12 to 30 miles up in the earths atmosphere, in a region called the stratosphere. 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. The thinning is most pronounced in the polar regions, especially over antarctica. The causes, mechanism and bioeffects of ozone layer depletion on humans were addressed. Ozone typically reaches its maximum depletion over. Achievements in stratospheric ozone protection ozone. Ozone depletion is usually worse further from the equator. It was first identified in 1970s due to the advent of supersonic aircraft, which fly in the lower stratosphere and emit nitrogen oxides. Experts blame ozonelayer depletion on manmade chem icals containing chlorine.
Increased depletion has recently started occurring over the arctic as well. Ozone layer is an international treaty designed to protect the ozone layerby phasing out the production of numerous substances that are responsible forozone depletion. Satellite instruments monitor the ozone layer, and we use their data to create the images that depict the amount of ozone. Ozone o3 is a stratospheric layer that plays important role in providing support to humans for their survival. Global warming is caused by the greenhouse effect, which is essential to life as we know it on planet earth. Foreword many people in europe are concerned about the impacts of climate change and stratospheric ozone depletion on human health. Stratospheric ozone absorbs most of the suns harmful uv radiation. Due to global warming and green house effect most of the heat is trapped in troposphere which is the layer below the stratosphere. 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. Ozone depleting substances are those substances which deplete the ozone layer. The hole story about earth s ozone hole through the years 1970 2011. Ozone layer protection european commission european union.
Acid rain and ozone layer depletion download ebook pdf. Ozone depletion and climate change environment canada. It is an essential factor for many global, biological and environmental phenomena. Ozone layer depletion is the thinning of the ozone layer present in the atmosphere. Pdf there are many situations where human activities have significant effects on the environment.
Click download or read online button to get the ozone layer book now. Overexposure to uv radiation can cause a range of health effects, including skin damage skin cancers and premature aging, eye damage including cataracts, and suppression of. Ppt ozone layer depletion authorstream presentation. Project report on ozone depletion environmental pollution. It covers the entire planet and protects life on earth by absorbing harmful ultravioletb uvb radiation from the sun. A warm ing trend and stratospheric ozone depletion. Generally, we find thinning or depletion of the ozone layer to the extent of ozone hole creation over the southern pole i. Ozone layer depletion is one of the major environmental issues which is getting thinner day by day as a. The ozone layer, located in the upper stratosphere 10 50 km above the earths surface, plays the highly important role in protecting life on this planet by absorbing harmful ultraviolet light uvb with wavelengths of between 280315nm. In this photograph, the two lowest layers of the atmosphere, the troposphere and the stratosphere, are clearly visible. The ozone layer download ebook pdf, epub, tuebl, mobi. One chlorine can destroy 100,000 molecules of ozone. As a result of international action, the ozone layer is expected to.
Ozone is earth s natural sunscreen, shielding life from dangerous solar ultraviolet radiation. Introductory course to the international legal framework. Ozone depletion occurs when the natural balance between the production and destruction of stratospheric ozone is tipped in favour of destruction. It was agreed on 16 september 1987, and entered into force on 1 january 1989. Global warming also leads to ozone layer depletion. It describes the benefits of these achievements, including healing the ozone layer, saving lives, and protecting the planet. Working safely with hydrocarbons video and booklet outlining safety precautions for using hydrocarbons as an efficient, costeffective replacement for.
This happens when the chlorine and bromine atoms in the atmosphere come in contact with ozone and destroy the ozone molecules. In addition, all figures are available for download, in three formats. Prolonged exposure to uvb radiation is linked to skin cancer, genetic damage and immune. Most important, we know that if the most potent odss were to continue to be emitted and increase in the atmo sphere, the result would be more depletion of the ozone layer.
Click any map image to bring up a new page with a highresolution image. The severe depletion of the ozone layer in any particular area is called ozone hole. The answers are updates of those first presented in the previous ozone assessment, scientific assessment of ozone depletion. Achievements in stratospheric ozone protection this report describes the achievements of the people, programs, and organizations that are working to protect the earths ozone layer. 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. Protecting the ozone layer department of the environment. In response to the prospect of increasing ozone depletion.
The ozone layer has not grown thinner since 1998 over most of the world, and it appears to be recovering because of reduced emissions of ozone depleting substances. The ozone depletion phenomenon the national academies press. Ozone depletion biology science fair project ideas. Downloads scientific assessment of ozone depletion 2018. These incidents were soon followed by the signature by the us and 180 countries of the montreal protocol on substances that deplete the ozone layer, an international treaty designed to phase out the production of a number of substances believed to be responsible for ozone depletion. Within the stratosphere, the ozone layer is the portion that contains the highest. The earths ozone layer is mainly found in the lower portion of the stratosphere from approximately 20 to 30.
Ozone layer depletion future commitments, document gefc. Global warming and ozone layer depletion are two different problems see the sidebar misconceptions about global atmospheric change on page 95. 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. Ozone depletion refers to the wearing out or reduction of the amount of ozone in the stratosphere. Ozone depletion results in an increase of uvb radiation, but the shorter the wavelength, the stronger the increase within the uvb range. Battling for oxygen using gumdrops and toothpicks, students conduct a largegroup, interactive ozone depletion model. Students explore the dynamic and competing upper atmospheric roles of the protective ozone layer, the suns uv radiation and harmful humanmade cfcs chlorofluorocarbons. To the point where a seasonal hole in the ozone layer began to appear above the antarctic. About depletion of the ozone layer is the anticipated increase in the amounts of. The increased use of humanproduced gases such as chlorofluorocarbons cfcs has led to a magnified springtime depletion of the protective ozone layer at both earths poles, especially over antarctica, a phenomenon well known as the ozone hole. When there was no ozone layer, life could only exist in. All of the assessment documents core assessment report, executive summary, and twenty questions and answers about the ozone layer. Tthe ozone hole and global he ozone hole and global global. Chloroflurocarbons, halons, hydroflurocarbons, hydrochloroflurocarbons.
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