服务承诺
资金托管
原创保证
实力保障
24小时客服
使命必达
51Due提供Essay,Paper,Report,Assignment等学科作业的代写与辅导,同时涵盖Personal Statement,转学申请等留学文书代写。
51Due将让你达成学业目标
51Due将让你达成学业目标
51Due将让你达成学业目标
51Due将让你达成学业目标私人订制你的未来职场 世界名企,高端行业岗位等 在新的起点上实现更高水平的发展
积累工作经验
多元化文化交流
专业实操技能
建立人际资源圈Air_Pollution
2013-11-13 来源: 类别: 更多范文
Air Pollution
Air Pollution
Air pollution also has a dramatic effect on natural resources. Ecosystems such as forests, wetlands, coral reefs, and rivers perform many important services for Earth's environment. They enhance water and air quality, provide habitat for plants and animals, and provide food and medicines. Any or all of these ecosystem functions may be impaired or destroyed by air pollution. Moreover, because of the complex relationships among the many types of organisms and ecosystems, environmental contamination may have far-reaching consequences that are not immediately obvious or that are difficult to predict. For instance, scientists can only speculate on some of the potential impacts of the depletion of the ozone layer, the protective layer in the atmosphere that shields Earth from the Sun's harmful ultraviolet rays.
Another major effect of air pollution is the tremendous cost of air pollution cleanup and prevention. The global effort to control emissions of carbon dioxide, a gas produced from the combustion of fossil fuels such as coal or oil, or of other organic materials like wood, is one such example. The cost of maintaining annual national carbon dioxide emissions at 1990 levels is estimated to be 2 percent of the gross domestic product for developed countries. Expenditures
air, pollution, rain, dioxide, carbon, percent, billion, layer, global, gases, forests, effect, ecosystems, cost, atmospheric, acid, year, wildlife, water, united, sun's, states, regions, reduce, rays, provide, production, pollutants, plants, ozone, one, lakes, known, increase, human, health

