首页
外语
计算机
考研
公务员
职业资格
财经
工程
司法
医学
专升本
自考
实用职业技能
登录
外语
The molecules of carbon dioxide in the Earth’s atmosphere affect the heat balance of the Earth by acting as a one-way screen. Al
The molecules of carbon dioxide in the Earth’s atmosphere affect the heat balance of the Earth by acting as a one-way screen. Al
admin
2009-06-24
51
问题
The molecules of carbon dioxide in the Earth’s atmosphere affect the heat balance of the Earth by acting as a one-way screen. Although these molecules allow radiation at visible wavelengths, where most of the energy of sunlight is concentrated, to pass through, they absorb some of the longer-wavelength, infrared emissions radiated from the Earth’s surface, radiation that would otherwise be transmitted back into space. For the Earth to maintain a constant average temperature, such emissions from the planet must balance incoming solar radiation. If there were no carbon dioxide in the atmosphere, heat would escape from the Earth much more easily. The surface temperature would be so much lower that the oceans might be a solid mass of ice.
Today, however, the potential problem is too much carbon dioxide. The burning of fossil fuels and the cleaning of forests have increased atmospheric carbon dioxide by about 15 percent in the last hundred years and we continue to add carbon dioxide to the atmosphere. Could the increase in carbon dioxide cause a global rise in average temperature, and could such a rise have serious consequences for human society? Mathematical models that allow us to calculate the rise in temperature as a function of the increase indicate that the answer is probably "yes".
Under present conditions a temperature of -8℃ can be observed at an altitude of 5 to 6 kilometers above the Earth. Below this altitude (called the radiating level), the temperature increases by about 6℃ per kilometer approaching the Earth’s surface, where the average temperature is about 15℃. An increase in the amount of carbon dioxide means that there are more molecules of carbon dioxide to absorb infrared radiation. As the capacity of the atmosphere to absorb infrared radiation increase, the radiating level and the temperature of the surface must rise.
One mathematical model predicts that doubling the atmosphere carbon dioxide would raise the global mean surface temperature by 2.5℃. This model assumes that the atmosphere’s relative humidity remains constant and the temperature decreases with altitude at a rate of 6.5℃ per kilometer. The assumption of constant relative humidity is important, because water vapor in the atmosphere is another efficient absorber of radiation at infrared wavelengths. Because warm air can hold more moisture than cool air, the relative humidity will be constant only if the amount of water vapor in the atmosphere increases as the temperature rises. Therefore, more infrared radiation would be absorbed and reradiated back to the Earth’s surface. The resultant warming at the surface could be expected to melt snow and ice, reducing the Earth’s reflectivity. More solar radiation would then be absorbed, leading to a further increase in temperature.
选项
A、concentrated at visible wavelengths
B、absorbed by carbon dioxide molecules
C、absorbed by atmospheric water vapor
D、reflected back to space by snow and ice
答案
A
解析
转载请注明原文地址:https://kaotiyun.com/show/FKTd777K
本试题收录于:
公共英语五级笔试题库公共英语(PETS)分类
0
公共英语五级笔试
公共英语(PETS)
相关试题推荐
TheAmericanFamilyIntheAmericanfamilythehusbandandwifeusuallyshareimportantdecisionmaking.Whenthechildrenar
TheAmericanFamilyIntheAmericanfamilythehusbandandwifeusuallyshareimportantdecisionmaking.Whenthechildrenar
TheAmericanFamilyIntheAmericanfamilythehusbandandwifeusuallyshareimportantdecisionmaking.Whenthechildrenar
Whydoestheauthormention,’Egypt’smightypyramidbuilders"?AccordingtoKrom,theEgypt’sOldKingdomfell
TheauthorofthepassagecouldnotgotosleeppartlybecauseWhatwastheweatherlikethatnight?
Whichofthefollowingideasaboutreligiousbeliefisexpressedbythespeaker?Whatistheauthor’sattitudetowardthenewr
NewIdeasIceland’sPresidentOlafurGrimssonistryingtodrivecarbondioxide(二氧化碳)undergroundto
NewIdeasIceland’sPresidentOlafurGrimssonistryingtodrivecarbondioxide(二氧化碳)undergroundto
TheImportanceofAgricultureinChinaThedevelopmentofagricultureandthebalancebetweenfoodandpopulationareChina’
MoreThanaRidetoSchoolTheNationalEducationAssociationclaims,"Theschoolbusisamirrorofthecommunity."Theyf
随机试题
婴儿出现(),如出血位置无法压迫,可让婴儿躺下,用拳头或手掌根部把出血的血管压向对侧的骨头方向。
常见的肛周脓肿是
治疗阴虚内热型内伤发热的首选方剂是
可能的诊断是若需要应采取的正确预防措施是
喜欢买报纸的人、常常________于报刊亭的人必然有着阅读的兴趣并养成了习惯,这样的行为不仅影响着个人的生活,也在________中影响着他人。将报刊亭打造成一个公共的阅读空间,就像现在随处可见的自助K歌房一样,这种________又便捷的阅读点,激发的
典型欠阻尼二阶系统超调量大于5%,则其阻尼ξ的范围为()。
从各国保险立法来看,关于投保人或被保险人的告知方式一般分为以下两种,即()。
某企业2011年年底“应付账款”科目月末贷方余额20000元,其中:“应付甲公司账款”明细科目贷方余额15000元,“应付乙公司账款”明细科目贷方余额5000元;“预付账款”科目月末贷方余额10000元,其中:“预付账款——甲工厂”明细科目贷方余额
Manystudentsfindtheexperienceofattendinguniversitylecturestobeareallyconfusingand【C1】______experience.Thelecture
Ithasbeenproventhatshortburstsofconcentrationrepeatedfrequentlyaremuchmore【B1】______thanonelongperiod.So,even
最新回复
(
0
)