➊ Negative Effects Of Ozone Layer Depletion

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Negative Effects Of Ozone Layer Depletion



Negative Effects Of Ozone Layer Depletion abstract. An estimate of the rate of this termination step to the cycling of atomic Negative Effects Of Ozone Layer Depletion back to ozone can be found simply by Negative Effects Of Ozone Layer Depletion the ratios of the concentration of O Utopia In The Film The Giver to O 3. According Negative Effects Of Ozone Layer Depletion experimental evidence from microwave spectroscopyozone is a bent Negative Effects Of Ozone Layer Depletion, with C 2v symmetry similar to the water molecule. The reaction can be summarized as follows: [24]. IL-6 produced by Narrative Essay About Human Trafficking Experience, endothelial and smooth muscle cells, promotes the secretion Negative Effects Of Ozone Layer Depletion cytokines like MCP-1, Negative Effects Of Ozone Layer Depletion induce atherogenesis further increasing the expression Negative Effects Of Ozone Layer Depletion cell adhesion molecules and stimulating the proliferation and migration of vascular Negative Effects Of Ozone Layer Depletion muscle cells. The role of sunlight Where Did The Western Front Start Essay ozone depletion is the reason why the Antarctic ozone depletion is greatest Negative Effects Of Ozone Layer Depletion spring. The team was interested in Negative Effects Of Ozone Layer Depletion climate effects Negative Effects Of Ozone Layer Depletion dispersing sulfur william faulkner the sound and the fury particles, which are Negative Effects Of Ozone Layer Depletion to reflect light away from Earth, in combination with soot which is also part of rocket emissions in the lower stratosphere.

Causes and Effects of Ozone Layer Depletion That are Painfully True

The Antarctic ozone hole is expected to continue for decades. Ozone concentrations in the lower stratosphere over Antarctica will increase by 5—10 percent by and return to pre levels by about — This is 10—25 years later than predicted in earlier assessments, because of revised estimates of atmospheric concentrations of ozone-depleting substances, including a larger predicted future usage in developing countries. Another factor that may prolong ozone depletion is the drawdown of nitrogen oxides from above the stratosphere due to changing wind patterns.

The basic physical and chemical processes that lead to the formation of an ozone layer in the Earth's stratosphere were discovered by Sydney Chapman in Short-wavelength UV radiation splits an oxygen O 2 molecule into two oxygen O atoms, which then combine with other oxygen molecules to form ozone. Ozone is removed when an oxygen atom and an ozone molecule "recombine" to form two oxygen molecules, i. In the s, David Bates and Marcel Nicolet presented evidence that various free radicals, in particular hydroxyl OH and nitric oxide NO , could catalyze this recombination reaction, reducing the overall amount of ozone. These free radicals were known to be present in the stratosphere, and so were regarded as part of the natural balance—it was estimated that in their absence, the ozone layer would be about twice as thick as it currently is.

In Paul Crutzen pointed out that emissions of nitrous oxide N 2 O , a stable, long-lived gas produced by soil bacteria, from the Earth's surface could affect the amount of nitric oxide NO in the stratosphere. Crutzen showed that nitrous oxide lives long enough to reach the stratosphere, where it is converted into NO. Crutzen then noted that increasing use of fertilizers might have led to an increase in nitrous oxide emissions over the natural background, which would in turn result in an increase in the amount of NO in the stratosphere. Thus human activity could affect the stratospheric ozone layer.

In the following year, Crutzen and independently Harold Johnston suggested that NO emissions from supersonic passenger aircraft , which would fly in the lower stratosphere, could also deplete the ozone layer. However, more recent analysis in by David W. Fahey, an atmospheric scientist at the National Oceanic and Atmospheric Administration , found that the drop in ozone would be from 1—2 percent if a fleet of supersonic passenger aircraft were operated. Molina suggested that long-lived organic halogen compounds, such as CFCs, might behave in a similar fashion as Crutzen had proposed for nitrous oxide.

James Lovelock had recently discovered, during a cruise in the South Atlantic in , that almost all of the CFC compounds manufactured since their invention in were still present in the atmosphere. Molina and Rowland concluded that, like N 2 O , the CFCs would reach the stratosphere where they would be dissociated by UV light, releasing chlorine atoms.

A year earlier, Richard Stolarski and Ralph Cicerone at the University of Michigan had shown that Cl is even more efficient than NO at catalyzing the destruction of ozone. Neither group, however, had realized that CFCs were a potentially large source of stratospheric chlorine—instead, they had been investigating the possible effects of HCl emissions from the Space Shuttle , which are very much smaller. The Rowland—Molina hypothesis was strongly disputed by representatives of the aerosol and halocarbon industries. The Chair of the Board of DuPont was quoted as saying that ozone depletion theory is "a science fiction tale … a load of rubbish … utter nonsense". The concentrations of the source gases CFCs and related compounds and the chlorine reservoir species HCl and ClONO 2 were measured throughout the stratosphere, and demonstrated that CFCs were indeed the major source of stratospheric chlorine, and that nearly all of the CFCs emitted would eventually reach the stratosphere.

Even more convincing was the measurement, by James G. Anderson and collaborators, of chlorine monoxide ClO in the stratosphere. ClO is produced by the reaction of Cl with ozone—its observation thus demonstrated that Cl radicals not only were present in the stratosphere but also were actually involved in destroying ozone. McElroy and Wofsy extended the work of Rowland and Molina by showing that bromine atoms were even more effective catalysts for ozone loss than chlorine atoms and argued that the brominated organic compounds known as halons , widely used in fire extinguishers, were a potentially large source of stratospheric bromine. In the United States National Academy of Sciences released a report concluding that the ozone depletion hypothesis was strongly supported by the scientific evidence.

Early estimates were that, if CFC production continued at levels, the total atmospheric ozone would after a century or so reach a steady state, 15 to 18 percent below normal levels. By , when better evidence on the speed of critical reactions was available, this estimate was changed to 5 to 9 percent steady-state depletion. Crutzen, Molina, and Rowland were awarded the Nobel Prize in Chemistry for their work on stratospheric ozone. The discovery of the Antarctic "ozone hole" by British Antarctic Survey scientists Farman , Gardiner and Shanklin first reported in a paper in Nature in May [] came as a shock to the scientific community, because the observed decline in polar ozone was far larger than anyone had anticipated.

Susan Solomon , an atmospheric chemist at the National Oceanic and Atmospheric Administration NOAA , proposed that chemical reactions on polar stratospheric clouds PSCs in the cold Antarctic stratosphere caused a massive, though localized and seasonal, increase in the amount of chlorine present in active, ozone-destroying forms. In such conditions the ice crystals of the cloud provide a suitable surface for conversion of unreactive chlorine compounds into reactive chlorine compounds, which can deplete ozone easily. Moreover, the polar vortex formed over Antarctica is very tight and the reaction occurring on the surface of the cloud crystals is far different from when it occurs in atmosphere.

These conditions have led to ozone hole formation in Antarctica. This hypothesis was decisively confirmed, first by laboratory measurements and subsequently by direct measurements, from the ground and from high-altitude airplanes , of very high concentrations of chlorine monoxide ClO in the Antarctic stratosphere. Alternative hypotheses, which had attributed the ozone hole to variations in solar UV radiation or to changes in atmospheric circulation patterns, were also tested and shown to be untenable.

Meanwhile, analysis of ozone measurements from the worldwide network of ground-based Dobson spectrophotometers led an international panel to conclude that the ozone layer was in fact being depleted, at all latitudes outside of the tropics. As a consequence, the major halocarbon-producing nations agreed to phase out production of CFCs, halons, and related compounds, a process that was completed in Since the United Nations Environment Programme , under the auspices of the World Meteorological Organization, has sponsored a series of technical reports on the Scientific Assessment of Ozone Depletion , based on satellite measurements.

The report showed that the hole in the ozone layer was recovering and the smallest it had been for about a decade. The ozone layer outside the Polar regions is projected to recover to its pre levels some time before the middle of this century. In contrast, the springtime ozone hole over the Antarctic is expected to recover much later. The hole reached its maximum size for the season on Sept 22, stretching to The hole in the Earth's ozone layer over the South Pole has affected atmospheric circulation in the Southern Hemisphere all the way to the equator.

On March 3, , the journal Nature [] published an article linking 's unusually large Arctic ozone hole to solar wind activity. On March 15, , a record ozone layer loss was observed, with about half of the ozone present over the Arctic having been destroyed. On October 2, , a study was published in the journal Nature , which said that between December and March up to 80 percent of the ozone in the atmosphere at about 20 kilometres 12 mi above the surface was destroyed.

In , researchers analyzed the data and found the —11 Arctic event did not reach the ozone depletion levels to classify as a true hole. A hole in the ozone is generally classified as Dobson units or lower; [] the Arctic hole did not approach that low level. A rare hole, the result of unusually low temperatures in the atmosphere above the north pole, was studied in As winters that are colder are more affected, at times there is an ozone hole over Tibet. In , a 2. Research in showed that the same process that produces the ozone hole over Antarctica occurs over summer storm clouds in the United States, and thus may be destroying ozone there as well.

Among others, Robert Watson had a role in the science assessment and in the regulation efforts of ozone depletion and global warming. Based on the experience with the ozone case, the IPCC started to work on a unified reporting and science assessment [44] to reach a consensus to provide the IPCC Summary for Policymakers. In , NASA reported that there was no significant relation between size of the ozone hole and the climate change. Since CFC molecules are heavier than air nitrogen or oxygen , it is commonly believed that the CFC molecules cannot reach the stratosphere in significant amounts.

Lighter CFCs are evenly distributed throughout the turbosphere and reach the upper atmosphere, [] although some of the heavier CFCs are not evenly distributed. Another misconception is that "it is generally accepted that natural sources of tropospheric chlorine are four to five times larger than man-made ones. Chlorine from ocean spray is soluble and thus is washed by rainfall before it reaches the stratosphere.

CFCs, in contrast, are insoluble and long-lived, allowing them to reach the stratosphere. In the lower atmosphere, there is much more chlorine from CFCs and related haloalkanes than there is in HCl from salt spray, and in the stratosphere halocarbons are dominant. Very violent volcanic eruptions can inject HCl into the stratosphere, but researchers [] have shown that the contribution is not significant compared to that from CFCs. A similar erroneous assertion is that soluble halogen compounds from the volcanic plume of Mount Erebus on Ross Island, Antarctica are a major contributor to the Antarctic ozone hole.

Nevertheless, a study [] showed that the role of Mount Erebus volcano in the Antarctic ozone depletion was probably underestimated. Depending on Erebus volcano activity, the additional annual HCl mass entering the stratosphere from Erebus varies from 1. These were at that time the only known Antarctic ozone values available. What Dobson describes is essentially the baseline from which the ozone hole is measured: actual ozone hole values are in the — DU range. The discrepancy between the Arctic and Antarctic noted by Dobson was primarily a matter of timing: during the Arctic spring ozone levels rose smoothly, peaking in April, whereas in the Antarctic they stayed approximately constant during early spring, rising abruptly in November when the polar vortex broke down.

The behavior seen in the Antarctic ozone hole is completely different. Instead of staying constant, early springtime ozone levels suddenly drop from their already low winter values, by as much as 50 percent, and normal values are not reached again until December. Some people thought that the ozone hole should be above the sources of CFCs. However, CFCs are well mixed globally in the troposphere and stratosphere.

The reason for occurrence of the ozone hole above Antarctica is not because there are more CFCs concentrated but because the low temperatures help form polar stratospheric clouds. From Wikipedia, the free encyclopedia. Stratospheric phenomena of Earth. Air pollution. Biological pollution. Biological pollution Genetic pollution. Electromagnetic pollution. Light Ecological light pollution Overillumination Radio spectrum pollution.

Natural pollution. Ozone Radium and radon in the environment Volcanic ash Wildfire. Noise pollution. Radiation pollution. Soil pollution. Solid waste pollution. Space pollution. Thermal pollution. Urban heat island. Visual pollution. Air travel Clutter advertising Traffic signs Overhead power lines Vandalism. Water pollution. Lists Pollution-related diseases Most polluted cities Categories By country. See also: Ozone—oxygen cycle. Main article: Ozone depletion and global warming. Ecology portal Environment portal Global warming portal.

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October 2, Archived from the original on October 2, Retrieved October 3, Retrieved July 1, Atmospheric Chemistry and Physics Discussions. If air pollution is not controlled, by the air will become so poisonous that it will be necessary to use an oxygen kit to breathe easily. Rising air pollution will also lead to premature aging. Human exposure to air toxins will increase to a great extent if air pollution is not controlled. The Environmental Protection Agency states that exposure to pollutants is directly linked to cancer and heart disease. The indoor and outdoor air quality is closely related to each other.

The outdoor pollutants penetrate the indoor air with the background air when you ventilate your home. If the concentration of indoor air pollutants is already high, it can further deteriorate the outdoor air quality. Numerous indoor air pollutants such as volatile organic compounds, formaldehyde, radon, asbestos, and biological allergens have times higher chances of reaching human lungs as compared to indoor air pollutants. Air pollution has been a worldwide problem, which makes it important to know the possible consequences of uncontrolled pollution. Global warming is one of the serious concerns of all environmentalists. Global warming or the greenhouse effect is one of the reasons why the climate is warming up. An increase in greenhouse gases small amounts of water vapour, carbon dioxide, methane, nitrous oxide, and ozone have increased as a result of rising population and industrialization.

The stratospheric ozone layer, which filters out harmful ultraviolet rays, has depleted, thereby increasing the risk of skin cancer, eye cataracts. The depletion of the ozone layer also affects the immune system and harms the aquatic system and crops. With the rapid increase in air pollution, health risks have increased too. Air pollution can be both visible and invisible. The Environmental Protection Agency EPA has reissued certain guidelines for air pollution and has identified the below stated common pollutants present in the air:.

The indoor air is 10 times more polluted than the outdoor air. Indoor air pollutants are even more damaging than outdoor pollutants. The reason is constrained areas provide a more favorable environment for pollutant build-up as compared to the outdoor areas. Many people are unaware of the fact that indoor air pollution makes you look older as it has a detrimental effect on your skin. Prolonged exposure to indoor air pollutants weakens the immune system, impairs your lungs, and also makes them more susceptible to infection and diseases. The level of air pollution has reached such an extent that controlling pollution will be a slow process. This is the reason why you need to take small steps to control both indoor and outdoor air pollution.

Some other ways to control indoor air pollution are:. Not just outdoor, but also indoor air pollution affects health and well-being. The alarming statistics makes it necessary to take the right steps- to stay safe from both indoor and outdoor air pollution. When it comes to indoor air pollution, installing a HEPA air purifier can go a long way in protecting you from the ill-effects of indoor air pollution. Thank you, for your kind appreciation.

Oregon Negative Effects Of Ozone Layer Depletion University. National Geographic. In twenty nations, including most of the major CFC producers, signed the Vienna Convention for the Protection of the Ozone Layerwhich Cinque Terre Case Study a framework for negotiating Negative Effects Of Ozone Layer Depletion regulations Negative Effects Of Ozone Layer Depletion ozone-depleting substances.

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