第1个回答 2013-08-12
下面是关于地球环境的一篇论文中空气污染部分，里面包括全球变暖、臭氧层破坏、酸雨，后面跟着提出了应对的一些措施。本来打算只给你全球变暖的部分，但又觉得它们都是联系在一起的，所以就都给你吧，需要修改一下才能贴合你的作文主题要求
Air Pollution
Air is the key matter of the human survival. Like fish can not live without water, human beings can not live without air. We can survive for five weeks without food, for five days without water, and for only five minutes without air. Not only do human beings need air, but also animals and plants do. Moreover, it holds ultraviolet ray from the solar and protects all beings; it adjusts the climate; it prevents water vapors running off to outer spaces. Therefore, air is valuable matter without which all beings could not survive. Since two million years ago, human beings have undergone a long way of evolution and development under the protection of the air. However, there is something wrong with the air quality today, which is called “Air Pollution”. With the rapid developing of industry and communications & transportation, urban districts enlarge constantly and population increases dramatically. All these elements make the pollutants in the air overstep the self-purification of the air and cause air pollution with some abnormal phenomena, such as global warming, depletion of ozonosphere, acid rain, etc.
1. Global Warming: Global warming means the temperature of the earth rises gradually. In the last century, the temperature underwent fluctuations in the form of “cold→warm→cold→warm” ; From 1980s on, it rises obviously. The main causation is that human beings burn a great number of mineral fuels (coal, petrol, etc) and discharge a great quantity of greenhouse gases, for example CO2 and CH4. These waste gases have super power of absorbing long-wave radiation reflected by the earth, causing greenhouse effect and resulting in the global temperature rising. Now, there is 23 million tons CO2 discharged into the air every year. Compared with the initial stages of 20 century, the amount increases by 20% and it is increasing with the speed of 0.5% per year. Global warming rearranges global rainfall; it melts glacier and frozen earth; it uplifts sea level. According to the scientist’s calculation, sea level will rise by 20cm by the year of 2030, and 65cm by the end of 21century.
2. Depletion of Ozonosphere: Ozonosphere hollow above the Antarctic is the most remarkable symbol of Depletion of Ozonosphere. It reached 27 million kilometers in 2003. The ozone layer above the South Pole is formed in 2 billion years while 60% of it is damaged only in a century by human beings. Ozonosphere is like an umbrella of the earth; it holds up ultraviolet ray and protects all beings. If ozonosphere reduces 1%, the ultraviolet ray reaching the earth will increase 2% and the patients of skin cancer will increase 8%; If the content of ozonosphere reduces 40%, the agricultural products will reduce 7.5% and aquatic resources will reduce 25%; If ozonosphere reduces 25%, the frequency of photochemical smog will increase 30% and the economic loss from material’s aging will reach 4.7 billion us dollars. Researchers show that it is human who should response to the depletion of ozonosphere. Some commodities and electrical appliance, like hair spray and refrigerant, are the very murders to ozonosphere because the contain CFCs, Halon and other harmful elements which destroy ozonosphere. Also, waste gases like NO and NO2 from cars and industries do harm to ozonosphere too.
3. Acid Rain: Another represent of air pollution is acid rain. It emerges numerous severe environmental problems, such as acidification of soil and lake, destruction of plants and ecology, corrosion of building materials and cultural relics, etc. Due to the long-distance transportation, acid rain has become a transnational pollution. It is mainly made up of sulfuric acid and nitric acid which come from discharged SO2, NO2 and so on. Most sulfuric is from fossil fuels, like coal, petrol and natural gas. With the enlarging of fossil fuels, the quantity of discharged SO2 is also enlarging.
Solutions to Air Pollution:
Air is the valuable resource that all beings cannot lack. Now that we have realized that it has been severely polluted, what can be done to prevent the pollution? With recent technology and economy, it is not easy to purify the polluted air. It seems that to control the pollution source is the central way to manage the pollution.
1. Heighten people’s awareness to avoid causing air pollution in their daily life. Air pollution is caused by human beings. Therefore, people should be aware of that and pay attention to reduce air pollution in their daily life. If everyone could use commodities and electrical appliance without polluting elements and could control himself to take bus instead of driving own car, the air will certainly become cleaner and clearer day by day. For my part, there are two main ways to heighten people’s awareness. The first one is heighten the educational level of people while the second is propaganda.
2. Establish rules and laws to control the discharge of air pollutants. Human consciousness is decided by his morality, and human morality should be restricted by rules and laws. Government ought to establish standards of various gases by rules to control the amount of harmful gases discharging. Laws also should be established to punish those people that their morality can not restrict themselves and break the rules. Else, the places f industries should be arranged by rules and laws so that we can make full use of the air’s self-purification. Rules and laws are the safeguard and play important roles.
3. Reduce and solve waste gases with technology. Different fuels do harm to the air differently, so we can choose less-polluting fuels and improve the equipment and condition of burning with the help of technology. Purifying and retrieving waste gases is another method of technology. There are plenty of manners to put it into practice, such as burning, freezing, liquid absorbing, etc.
4. Plant trees and grassland in and around the city. By this way of virescence, it can not only beautify the environment but also release air pollution because plants can absorb CO2, SO2 and other waste gases.