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
One of the most difficult aspects of deciding whether current climatic events reveal evidence of the impact of human activities
One of the most difficult aspects of deciding whether current climatic events reveal evidence of the impact of human activities
admin
2017-05-11
63
问题
One of the most difficult aspects of deciding whether current climatic events reveal evidence of the impact of human activities is that it is hard to get a measure of what constitutes the natural variability of the climate. We know that over the past millennia the climate has undergone major changes without any significant human intervention. We also know that the global climate system is immensely complicated and that everything is in some way connected, and so the system is capable of fluctuating in unexpected ways. We need therefore to know how much the climate can vary of its own accord in order to interpret with confidence the extent to which recent changes are natural as opposed to being the result of human a activities.
Instrumental records do not go back far enough to provide us with reliable measurements of global climatic variability on timescales longer than a century. What we do know is that as we include longer time intervals, the record shows increasing evidence of slow swings in climate between different regimes. To build up a better picture of fluctuations appreciably further back in time requires us to use proxy records.
Over long periods of time, substances whose physical and chemical properties change with the ambient climate at the time can be deposited in a systematic way to provide a continuous record of changes in those properties overtime, sometimes for hundreds or thousands of years. Generally, the layering occurs on an annual basis, hence the observed changes in the records can be dated. Information on temperature, rainfall, and other aspects of the climate that can be inferred from the systematic changes in properties is usually referred to as proxy data. Proxy temperature records have been reconstructed from ice core drilled out of the central Greenland ice cap, calcite shells embedded in layered lake sediments in Western Europe, ocean floor sediment cores from the tropical Atlantic Ocean, ice cores from Peruvian glaciers, and ice cores from eastern Antarctica. While these records provide broadly consistent indications that temperature variations can occur on a global scale, there are nonetheless some intriguing differences, which suggest that the pattern of temperature variations in regional climates can also differ significantly from each other.
An advantage of proxy records over instrumental records is that______.
选项
A、they are more- reliable measures of climatic variability in the past century
B、they reveal information about the human impact on the climate
C、they provide more-accurate measures of local temperatures
D、they provide information on climate fluctuations further back in time
答案
D
解析
细节题。文章第二段开头指出instrumental records do not go back far enough toprovide us with reliable measurements of global climatic variability on timescales longer than acentury.接着文章介绍了proxy record,指出通过这种方法人们能够了解气候在很久以前的变化过程,故D选项符合文意。
转载请注明原文地址:https://kaotiyun.com/show/oCFO777K
0
考博英语
相关试题推荐
Writeanessayonthegiventopic,OnunrestrainedConsumption.Basedonthefollowingoutline,presentyourargumentwithsuppo
Itdidn’thappenovernight.Theproblemofpollutedairhasbeenfesteringforcenturies.Suddenlytheproblemofairpollut
Themostconvincingevidencefortheimportanceofadultinfluenceonachild’sintelligencecomesfromastudyof"atrisk"chil
AWorldWithoutBooksOrMusicIfbookshadneverbeendiscovered,manwouldhavefoundsomeotherwayofrecordinghiscomm
ThismonthSingaporepassedabillthatwouldgivelegalteethtothemoralobligationtosupportone’sparents.CalledtheMai
Largecompaniesneedawaytoreachthesavingsofthepublicatlarge.Thesameproblem,onasmallerscale,facespracticallyev
Westernscholarsgenerallyrecognizetwomainkindsofriddle:thedescriptiveriddleandthewittyquestion.
IntheHanDynasty,theroyalgovernmentsentspecialenvoystothewesterncountriestodisseminatetheChineseculture.
Americanculturehasnotbeenimmunetoculturalinfluencesfromoutside.TheideaofdemocracycamefromtheancientGreeks;th
AimlessnesshashardlybeentypicalofthepostwarJapanwhoseproductivityandsocialharmonyaretheenvyoftheUnitedStates
随机试题
按矫正时被矫正工件的温度分类可分为()两种。
条件反射的特点是()
A.间日疟原虫、恶性疟原虫B.恶性疟原虫、三日疟原虫C.三日疟原虫、卵形疟原虫D.间日疟原虫、三日疟原虫E.间日疟原虫、卵形疟原虫疟疾复发率较高的感染疟原虫种类
A.志贺痢疾杆菌B.福氏痢疾杆菌C.舒密次痢疾杆菌D.鲍氏痢疾杆菌E.宋内痢疾杆菌我国近年来引起菌痢最常见的病原菌是
血管壁功能异常见于
猩红热出现皮疹多在发热后( )。
创造性思维是多种思维的综合表现,包括()。
求的间断点并分类.
Inwinter,mostanimalshaveahardtime______anythingtoeat.
Scientistshavedevelopedanewcancerdrug.Sofar,theyhavetasteditonlyon【B1】______animals.Thedrugisdesignedto【B2】__
最新回复
(
0
)