Effects Of Depletion Of Ozone Layer example essay topic

OZONE LAYER DEPLETION"A giant asteroid could hit the earth! Something else could happen! The global temperature could rise! Wakeup! " (edf. org) Science is a body of knowledge containing various streams such as physics, chemistry, biology etc". Its sub-behavioral concept is Technology, which has made tremendous changes in the modernized world. Climate isa field of the science.

Climate is a natural consequence in which all the human being sexist". (Technology and Environment page 25)". The first thing people see, in the morning, when they walkout side is the sky or the colored sun. Is this world giving us the privilege of seeing the natural colors of the sun through all the layers of pollution with inthe air? " A blanket of air, which we call the atmosphere, surrounds the Earth. It reaches over 560 kilometers (348 miles) from the surface of the Earth, so we are only able to see what occurs fairly close to the ground.

Early attempts at studying the nature of theatmosphere used clues from the weather, the beautiful multi-colored sunsets and sunrises, and the twinkling of stars. With the use of sensitive instruments from space, we are able to get a better view of the functioning of our atmosphere". The atmosphere, solar energy, and our planet's magnetic fields support life on Earth. The atmosphere absorbs the energy from the Sun, recycles water and other chemicals, and works with the electrical and magnetic forces to provide a moderate climate. The atmosphere also protects us from high-energy radiation and the frigid vacuum of space. The envelope of gas surrounding the Earth changes fromthe ground up.

Four distinct layers have been identified using thermal characteristics (temperature changes), chemical composition, movement, and density. That comprises of Troposphere, Stratosphere, Mesosphere and atmosphere. The atmosphere is primarily composed of Nitrogen (N 2, 78%), Oxygen (O 2, 21%), and Argon (AR, 1%). Argon includes all the other gases present in the atmosphere. A myriad of other very influential components are also present which include the water (H 2 O, 0 - 7%), 'greenhouse' gases or Ozone (O SUB 3, 0 - 0.01%), Carbon Dioxide (CO 2, 0.01-0.1%), The envelope of gas surrounding the Earth changes fromthe ground up". (Climate of Hope, p. p. 25~63) Now, the interesting fact is the information of layer of atmosphere, which surrounds our atmosphere".

Orbiting above the Earth, an astronaut can look dow non our home and see the thin blue ribbon that rims our planet. That transparent blanket in our atmosphere makes life possible". Yes, It is the Ozone Layer. It provides the air we breathe and regulates our global temperature.

And it contains a special ingredient called ozone that filters the solar radiation. Life a swe know it is possible in part because of the protection afforded by the ozone layer... The term itself comes from the Greek word meaning 'smell,' a reference to ozone's distinctively pungent odor". Each molecule contains three oxygen atoms bonded together in the shape of a wide triangle. In the stratosphere, new ozone molecules are constantly created in chemical reactions fueled by power from the sun. The recipe for making ozone starts off with oxygen molecules.

When struck by the sun's rays, the molecule split apart into single oxygen atoms, which are exceedingly reactive. Within a fraction of a second, the atoms bond with nearby oxygen molecules to form triatomic molecules of ozone" (Climate Change)". Ozone is an allotrope of Oxygen. Allotropes are two or more forms of an element with different chemical and physical properties. Molecules of diatomic oxygen, the form of oxygen with which most the people are familiar, contain two atoms each, as shown the formulaO 2. In contrast, molecules of ozone contain three atoms each and are represented by the formulaO 3".

(Kelvin, page 46). Both oxygen produces ozone and anthropogenic (human caused) sources. In the troposphere the layer of atmosphere nearest to theearth's surface, ozone is generated in a complex series of reactions associated with the combustion of fossil fuels". Ozone is most commonly found in the air above the urban areas where sunlight initiates these reactions among the products released from automobile and truck exhausts. Since troposphere ozone can cause damage to the living organisms, especially plants, itis regarded as pollutant. The solution is very different in the stratosphere, the next higher layer of the atmosphere.

Thee ozone is produced by natural processes. And had a beneficial function for the terrestrial organisms" (M. Minaret's, ). In thestratosphere, radiant energy from the sun can cause an oxygen molecule to break apart into two oxygen atoms: O 2 = O + O. Each oxygen atom can then react with other oxygen molecules to form ozone. O + O 2 = O 3 The stratospheric concentration of ozone therefore represents a balance, established over the aeons, before creative and destructive forces".

The total level of ozone in the stratosphere remains fairly constant, an arrangement resembling a tank with open drains.) For about a billion years, the natural ozone system worked smoothly, but now human beings have upset the delicate balance. By polluting theatmosphere with additional chlorine-containing chemicals, we have enhanced the forces that destroy ozone -- a situation that leads to lower ozoneconcentration in the stratosphere". The addition of these chemicals is the same as drilling a larger " chlorine' drain in the tank, causing the level to drop". (Flavin, Introduction) Stratospheric ozone is primarily created by ultraviolet (ULTRA VIOLET) radiation. The Sun's output affects the rate at which it is produced. The Sun " senergy release in the ULTRA VIOLET part of the spectrum does vary, especially over the well-known 11-year sunspot cycle.

Observations over several solar cycles since the 1950's show that total global ozone levels decrease by 1 to 2% from the maximum to the minimum of a typical solar cycle. Even as the sun " senergy produces new ozone, natural compounds containing nitrogen, hydrogen, and chlorine continuously destroy these gas molecules. Such chemicals were all present in the stratosphere -- in small amounts -- long before humans began polluting their. Nitrogen comes from soils and oceans, hydrogen comes mainly from atmospheric water vapor, and chlorine comes from the oceans".

By the middle of the twenty first century, there is evidence that the Earth will be warmer than it has been at any time in human history, and quite possibly since the end of the dinosaurs, some 65 billion years ago. If we stay atthe rate we our now (fossil fuel consumption / growth in population) then within the next two century theEarth's air might not be fit to breath."The term greenhouse effect is used to describe the increased warming of the Earth's surface and lower atmosphere due to increased levels of carbon dioxide and other atmospheric gases that absorb radiated energy in theatmosphere and then reradiate it back to the surface. The recently -observed long-term changes in ozone are much greater than this. They cannot be attributed to changes in solar activity". (Cogan, p. p. 24~32). Here comes about the major scientific problem occurring in today's climate causing warming of earth and leading world atmosphere to dangerousconsequences.

Yes, it is the hole in the ozone layer known as the "Ozone Layer Depletion". Gradually, ith as become clear to scientists and to governments alike that human activities are threatening our ozone shield. Behind these environmental problem lies a tale of twin challenges: the scientific quest to understand our ozone shield and the debate among governments over how to best protect it. Ozone layer Depletion is now a days a very major scientific problem. A totally depleted ozone layer would render the earth's surface inhabitable". In the U.S. by the next century if thematter of ozone was not looked into" (global warming. org)".

We wouldn't be able to go outside without wearing hats at that time, and wewouldn't be able to build things out of plastic and rubber that would be exposed to the sunlight because they would deteriorate much faster", says Toyland, environmental protection specialist working with the united states environmental protection agency, while speaking about the worst effects of the ozone layer depletion" (Atmospheric Ozone-I). Looking at these andmany such effects one wonders as to what depletion actually is? And what are the impossible solutions fort? To understand it clearly, we should look in thematter in four steps, What is causing the depletion ofthe ozone layer? What are the effects of depletion of ozone layer and what are possible solutions to the problem? "Damage to the ozone layer has dangerousconsequences for humans, because the ozone molecules function As a shield from the sun's radiation, absorbing some of the harmful ultraviolet rays, before it reaches the earth's surface" (greenhouse. net)".

Concerns about damage to the ozone layer go back tothe early 1970's. A number of scientists were concerned by two possible threats to the ozone layer: rockets fired off by the U.S. National Aeronautics and space Administration (NASA) and proposed Supersonic (SST) aircraft. Calculation suggested those chlorine atoms released by rockets and SST's could bring about the decomposition of ozone molecules witha subsequent deterioration of the ozone layer. In 1974, however, an even more troubling threat to theozone layer was identified". (Atmospheric Ozone -II)".

Two American scientists Mario Moline and F. Sherwood Rowland, hypothesized that a group of compounds know nass chlorofluorocarbons (CFC's) could release chlorine in the stratosphere and damage the ozone layer" (American Geophysical Union, Journal). CFC's are simply organic compounds made up of chlorine, carbon and fluorine". The fact that (CFC's don't break down is a benefit for there many applications but a curse for the stratospheric ozone. They have become very popular as a propellant in Aerosol sprays such as deodorants, hair sprays, spray paints, pesticides and similar materials (P 4). Because CFC's are not dissolved by rain, over the years they rise, over the years they rise to the ozone layer in thestratosphere, about 10 to 20 miles (15 to 30 kilometers) above the earth's surface". (Atmospheric Ozone- ) There, CFC's can linger for 100 years, while the sun's harsh radiation breaks them down, releasing atomic chlorine.

One chlorine atom can destroy more than 100,000 ozone molecules (Transportation, pp. 67-72). a group of scientists including the Nobel prize winner Mario Moline, in the late 70's discovered another chemical that was gobbling up the earth's ozone". The chemical was know nas Methyl Bromide. Methyl Bromide was widely used as a soil fumigant in growing certain fruits and vegetables" (Earth Care Annual). Ozone's structure allows it to absorb a certain kind of ultraviolet sunlight that would otherwise reach the surface of the earth ad effect the living material (Hazardous Air Pollutants, page 35). Ozone's absorption of ultraviolet rays is critical for the well being of mankind". ULTRA VIOLET radiation is typically broken down into three parts: ULTRA VIOLET-a (320 to 400 NM), ULTRA VIOLET-b (280 to 320 NM), and ULTRA VIOLET-c (200 to 280 NM).

ULTRA VIOLET-c is quickly absorbed by small amounts of Ozone, (Earth care Annual, page 26~37) Exposure to ULTRA VIOLET-b can cause damage to DNA (which carries the genetic information in living organisms). Changing regional climate could alter forests, crop yields, and water supplies. It could also threaten human health, and harm birds, fish, andmany types of ecosystems. Deserts may expand into existing rangelands, and the character of some of our National Parks may be permanently altered. Unfortunately, many of the potentially most important impacts depend upon whether rainfall increases or decreases, which can not be reliably projected for specific areas". (Hazardous Air Pollutants, page 53~129).

Scientists have been seriously considered this problem and have been working towards the solution of this problem. There have a few good proceedings, butt here is no perfect solution for it as for now". . On eof the most serious effects of global warming, as it continues to intensify, is the increase in the ocean levels". Thermal expansion of the ocean and glacial melting are likely to cause a. 5 to 1.5 meter rise inthe ocean level by the year 2100.

As the ocean level rises and if no protection is provided, many freshwater supplies could be jeopardized. Tens and possibly hundreds of millions of people will lose their water supplies to salt water intrusion because of sea level rise. The warming of ocean surface waters could possibly create more powerful hurricanes, cyclones, and windstorms". (Benard e, page 59). Global warming will also have a drastic effect on the climate of the world in areas such as weather patterns and water resource supplies.

The Thinning off theearth's ozone layer has allowed greater amount of skin-burning UV-radiation from the sun to reach theearth. Increased exposure to UV has been shown to harm human health, damage freshwater and marine ecosystems, reduce crop yields, and affect forests. The most basic impact for humans is the increase in skin cancers. Over exposure to the sun's UV rays can also cause eye damage, including cataracts, and may even weaken the immune system.

It has impact on agriculture, including many of the world' major food crops. It has been observed that some crops, such as barley and oats, have shown decreased growth as a result of exposure to increased UV- radiation. In marine ecosystems, it can damage the tiny single -celled plants, known as phytoplankton, which form the base of the food chain. Decreases in the food source at this early stage, may have effects throughout the entire system, and could ultimately affect fish populations.

Increased UV levels also reduce the lifetime of construction materials used outdoors, particularly the plastics that are prevalent in our homes, playgrounds, another structures. Forestry research found that trees, which grow at higher elevations, are more resistant. Global warming research is giving more indications, although certainly not proof, that highly volatile weather patterns are one of the consequences of rising atmospheric concentrations of greenhouse gases". These altered weather patterns can have many effects such as floods, droughts, and reduction in the amount and quality of water resources. There is no indication whether there is going to be an increase or decrease in the total precipitation".

(Bigg, page 399). Many areas will have a substantial amount of rainfall causing severe flooding, while other areas will have major droughts". However global warming will create a decrease in the snow pack in many mountainous areas because the high winter temperatures could cause more precipitation to fall as rain than as snow. This could create a run off that would fill downstream reservoirs too early. Thus, during the spring when the reservoirs are normally filled, they would not be able too, because of the early snowmelt. As a result, the reservoirs would have a reduced amount of storage for the summer and fall".

(Hewitt, page 486). Some other areas that are effected by the increase in greenhouse gases are agriculture and ecosystems. Lower water supplies and increased weather variability may hurt the agriculture industry. On the other hand, a longer growing season and increased growth that would be stimulated by higher levels of carbon dioxide may also help it". The increase in temperature and dryness could also effect plant life and animal life. Natural ecosystems are in delicate balance with their environments and climates.

The impacts of climate change become more severe with increases in both the magnitude and the rate of change". (Russell, p. p. 329~538). If the temperatures do rise as predicted several things could happen". The increases of temperature could alter the growth of crops in areas near the equator due to insufficient rain and heat.

This could really hurt countries that rely on imported food. With the high temperatures the polar ice caps could melt and cause the sea water level to go up 1 to 3 feet. This increase could take out small islands, coastal cities and some shallow rivers. The Everglades in Florida would be almost if not totally wiped right off the map. The Everglades is the home for many animals and plant life. If it did get flooded, they would all have to move northward across very dry land which they will not be able to endure for very long.

When the hot temperatures do spread southward and northward, tropical disease will spread with it. Disease that were down in Mexico will maybe occur in The Carolinas or eventually Vermont. These new diseases will be hard to deal with causing m anymore deaths and illnesses than before. The financial problem with this is, that the flooding will cause dams to be built and cities to be reconstructed. The shortage of food will cause the price of the food togo up and with all the diseases we will need more medical supplies and workers. All of this combined could and will cost a lot of money if we don't do something about it now.

The computer models can " t predict exactly what the climate is going to be in the future, but they can come close to what it will belike down the road. Scientists proved this by predicting with computers what the climate was in the past". (enviro web. org). Looking at the units used to measure the ozoneconcentration are the Dobs in Unit (DU) - the principle unit for measuring ozone concentration. One DU is about twenty- seven million molecules per square centimeter (the palm of your hand covers an area of roughly a hundred square centimeters).

The ozoneconcentration over the US is about 300 DU and the antarctic hole during the late spring can drop to 117 DU. The another is Mixing ratios: within a specified volume, it is a fraction of the number of molecules ofa particular gas divided by the total number of molecules in that given space". The Cretaceous occurred over 100 million years ago. It was the warmest period we have knowledge of yet. There was so much carbon dioxide in the air that the oceans rose many meters. North America was flooded and split apart into two pieces.

The temperature then was more than fifteen degrees greater than the average temperature today". (gc rio. org). Scientists believe that the tilt of the earth's axis changes to tilt the opposite way every 10,000 years like a cycle. While going through this cycle it will change the climate of areas. Right now it is moving so that North America is going to be close to the sun in the winter. Seasons become more extreme when the opposite happens. This controls the cycle of ice ages".

Volcanoes when they erupt, send clouds of dust into the air blocking sunlight. This would cool the earth off more. Oceans are known to absorb CO 2 because of the ocean currents and the action of plankton. There is some evidence that there is naturally rapid climate change between each Ice Age, which confuses the whole global warming and idea". (too warm. com). While it's true that volcanoes and oceans release large amounts of chlorine, the chlorine form these sources dissolves in water so it washes out of the lower atmosphere in rain. CFC's do not dissolve in water and are not broken down in the lower atmosphere.

Human-made molecules reach the stratosphere and then release chlorine and bromine. Measurements show thatthe increase in stratospheric chlorine since 1985 matches the amount of CFC's and other ozone-depleting substances released by human activities. The first real evidence of ozone depletion was reported in 1985 by the British Antarctic Survey team, which had been measuring the ozone layer over the South Pole for 18 years. Here, they found a dramatic thinning in theozone layer, which developed every year form September to November.

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