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. A
The molecules of carbon dioxide in the Earth’ s atmosphere affect the heat balance of the Earth by acting as a one-way screen. A
admin
2014-12-26
17
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 low 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 clearing 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 -18℃ can be observed at an altitude of 5 to 6 kilometres above the Earth. Below this altitude(called the radiating level), the temperature increases by about 6℃ per kilometre 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 increases, the radiating level and the temperature of the surface must rise.
One mathematical model predicts that doubling the atmospheric 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 kilometre. The assumption of constant relative humidity is important, because water vapour 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 vapour 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.
According to the passage, which of the following is true of the last hundred years?
选项
A、Fossil fuels were burned for the first time.
B、Greater amounts of land were cleared than at any time before.
C、The average temperature at the Earth’ s surface has become 2°C cooler.
D、The amount of carbon dioxide in the atmosphere has increased measurably.
答案
D
解析
细节题。根据last hundred years定位到第二段The burning of fossil fuelsand the clearing of forests have increased atmospheric carbon dioxide by about 15percent in the last hundred years“矿物燃料的燃烧和森林的砍伐使大气中的二氧化碳在过去的百年中增加了大约15%”可知D选项正确。
转载请注明原文地址:https://kaotiyun.com/show/YBh7777K
0
大学英语六级
相关试题推荐
Thepurposeofaletterofapplicationistohelpyouto"sell"yourself.Itshouldstateclearlythejobyouwant,andshouldt
Americansareahighlymobilepeople.Whatfactorscausethemtomove?The(36)______foreconomicbettermentisgenerallythemos
AteamofGermanscientistshastakenpicturesofanancientfishthatwasthoughttohavediedoutlongago.Thepicturesmayp
Ahappymarriageapparentlyisgoodmedicine,buthostilespousesmaybeharmfultooneanother’shealth.Couplesin【B1】______m
ImprovingthebalancebetweentheworkingpartofthedayandtherestofitisagoalofagrowingnumberofworkersinrichWe
ImprovingthebalancebetweentheworkingpartofthedayandtherestofitisagoalofagrowingnumberofworkersinrichWe
A、Theywereexpensive.B、Noonebelievedthem.C、Theywereunsuccessful.D、Theywereoftennotwelcomed.C文章提到,第一代的绿色广告因为市场营销不佳,
Amongthegovernment’smostinterestingreportsisonethatestimateswhatparentsspendontheirchildren.Notsurprisingly,th
Inthemidstofaperiodofrapidlanguageextinction,withalanguageestimatedtodieeverytwoweeks,linguistshavefounda
Inthemidstofaperiodofrapidlanguageextinction,withalanguageestimatedtodieeverytwoweeks,linguistshavefounda
随机试题
化学工业的原料来源很广,可来自矿产资源、动物、植物、空气和水,也可以取自其他工业、农业和林业的副产品。()
A.HPV16型B.HPV8亚型C.两者皆有D.两者皆无与宫颈尖锐湿疣发生有关的感染是
下列不属于“但寒不热”的是()
企业选择外部招聘渠道时可以使用的方法有()。
某企业为增值税一般纳税人。2009年1月进口一批化妆品,关税完税价格40万元。已知:化妆品关税税率为20%、消费税税率为30%。该企业进口化妆品应纳进口增值税税额为( )万元。
企业制造费用的分配方法通常包括()。
AS公司外币业务采用即期汇率的近似汇率进行折算,按月计算汇兑损益。(1)2012年1月即期汇率的近似汇率为1美元=6.50元人民币。各外币账户的年初余额如下:(2)公司2012年1月有关外币业务如下:①本月销售商品价款300万美元,货款尚未收回(
下列项目中不属于“男子三项那达慕”的是()。
“授之以鱼,仅供一饭之需;授之以渔,则终身受用无穷”,这主要说明教学应该重视()。
简述弥尔顿与《论出版自由》。(中国传媒大学2015年研)
最新回复
(
0
)