英語論文.doc

An Exploration on the Effects of Air PollutionClass: 31320114370 Zhang Jiang AbstractAir Pollution is not a new topic. It is a problem that we have noticed since the industrial revolution, when trees, houses and cars were covered in soot from the factories. People demanded change then, just as they are demanding it now.Acid rain, global warming and ozone depletion are three serious problems of air pollution. Acid rain occurs when the moisture in the air mixes with Carbon, Nitrogen, and Sulphur gases. The greenhouse effect is caused by solar energy being trapped by CO2, Methane, Ozone (O3), Nitrous gas, and Chlorofluorocarbons (CFCs) that are in the air. In this paper, you will know the effects they have and learn how the ozone depletion happens.With all the talk of acid rain, global warming and ozone depletion it seems hopeless, but it isnt. Everyone can make a difference. After reading this you will learn possible solutions to the problems of air pollution. You will also see things are bad but not hopeless.Key words: air pollution; acid rain; global warming; ozone depletion; solutionsPart One Acid RainAcid Rain is the term given to any precipitation that is above normal acidity, this includes snow and fog. Damage caused by acid rain is tremendous. The acid in the rain bonds with the minerals in the soil, tying them up so that plants can not use them. The plant becomes mineral deficient and weak. The rain also kills the plants leaves, further weakening it and making the plant more susceptible to fungus and other diseases. This is a major agricultural problem.The rain effects lakes, rivers and the animals living within them. The plants in the lakes and rivers are killed in the same way as land plants. The fish and other animals are left with no food. The animals that do survive are killed from the metals being drawn into the water from the soil, when the acid bonds to them. Many architectural structures are destroyed from the acid rain. Most of the cement used to make our buildings. are made from lime which is very reactive with acid. You can see the effects of this weathering if you look at old gravestones or statues. The words etched in some of the gravestones can barely be read anymore because they are so worn away. Weathering is a natural process. Rain is normally slightly acidic but because of air pollution and the higher acidity of the rain, the process is sped up greatly.Industry is looking for solutions to the air pollution problem. The best solution would be to stop burning fossil fuels all together but at this time we have no other alternatives. Scientists are trying ways to cut down on pollution. One way is to wash the coal before they burn it. Washing it takes off most of the sulphur but not all of it. The rest would have to be removed chemically but this process is still being researched. The problem with this is what to do with all the excess sulphur. Another solution is to clean the smoke before it is released into the air. Many filters have been installed in smoke stacks but again this solution is not 100% effective.Part Two Global WarmingAnother major environmental problem caused by air pollution is global warming or the greenhouse effect. Some people may wonder why global warming is bad. Who wouldnt want summer year around? The reason is that it wouldnt stop at a comfortable warm all year around. The winters would be warm and the summers would be unbearably hot! Some scientists believe that if the trend continues and becomes worse, we will have to abandon the southern areas and keep moving north to escape the heat. Many places will become dry arid dessert. This great warming also brings up the idea of what will happen to all the ice at the poles? With the temperature rising, the ice will melt and sea levels will rise significantly. Most of our costal land is only a few feet above sea level. A rise would flood all of it including most of the state of Florida!We can slow down the greenhouse and maybe even stop it by slowing down and stopping the release of the greenhouse gases. One of the ways this is being done is by putting the catalytic converter on cars. The device goes on the exhaust pipe of the car and reduces the amount of CO2 that is released into the atmosphere. Another way is to control the use of CFCs. Aerosol cans are supposed to be banned by the year 2000 and they are working on new coolants for refrigerators and air conditioners. We can also slow down the rate of deforestation and plant more trees.Part Three Ozone DepletionThe last major environmental problem caused by air pollution is ozone depletion. As mentioned before ozone is three oxygen molecules (O3). It is concentrated in the stratosphere about 20-25 km above the earths surface. Ozone is what protects us from shriveling up under the suns powerful rays. It blocks out the harmful ultraviolet (UV) light which causes skin cancer. Two major holes have been discovered in the ozone layer: a large one above the south pole and a smaller one above the north pole. These two areas have absolutely no protection from UV light.Part Four ConclusionThe problems above may seem serious but right now they are not irreversible. We can do some everyday things that will help the environment.Make sure that you only have lights on in the room you are in. If you turn lights off as you leave a room and dont leave every light in the house on, less electricity has to be produced at Detroit Edison, that means less coal will be burned and less CO2 and the other gases will be produced and released into the air. Another easy way to help is to plant a tree in your yard or to get involved in a tree planting program. Buy pump bottles instead of aerosol cans or you