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
"Rising Sea Levels" Sea level must be expressed as a range of values that are under constant reassessment. During the last ce
"Rising Sea Levels" Sea level must be expressed as a range of values that are under constant reassessment. During the last ce
admin
2018-07-24
48
问题
"Rising Sea Levels"
Sea level must be expressed as a range of values that are under constant reassessment. During the last century, sea level rose 10-20 cm (4-8 inches), a rate 10 times higher than the average rate during the last 3000 years. The 2007 IPCC (Intergovernmental Panel on Climate Change) forecast scenarios for global mean sea level rise this century, given regional variations, are
- Low forecast: 0.18 m (7.1 in.)
- Middle forecast: 0.39 m (15.4 in.)
- High forecast: 0.59 m (23.2 in.)
Observations since 1961 show the average global ocean temperature increased to depths of 3000 m and the ocean absorbed more than 80% of climate system heating. Such warming causes thermal expansion of seawater, contributing to sea level rise. Mountain glaciers and snow cover declined on average in both hemispheres, contributing to sea level rise. Mount Kilimanjaro in Africa, portions of the South American Andes, and the Himalayas will very likely lose most of their glacial ice within the next two decades, affecting local water resources. Glacial ice continues its retreat in Alaska.
Surrounding the margins of Antarctica, and constituting about 11% of its surface area, are numerous ice shelves, especially where sheltering inlets or bays exist. Covering many thousands of square kilometers, these ice shelves extend over the sea while still attached to continental ice. The loss of these ice shelves does not significantly raise sea level, for they already displace seawater. The concern is for the possible surge of grounded continental ice that the ice shelves hold back from the sea.
Although ice shelves constantly break up to produce icebergs, some large sections have recently broken free. In 1998 an iceberg the size of Delaware broke off the Ronne Ice Shelf, southeast of the Antarctic Peninsula. In March 2000 an iceberg tagged B-15 broke off the Ross Ice Shelf (some 90° longitude west of the Antarctic Peninsula), measuring twice the size of Delaware, 300 km by 40 km or 190 mi by 25 mi. Since 1993, six ice shelves have disintegrated in Antarctica. About 8000 km (3090 mi) of ice shelf are gone, changing maps, freeing up islands to circumnavigation, and creating thousands of icebergs. [A] Larsen-A suddenly disintegrated in 1995. [B] In only 35 days in early 2002, Larsen-B collapsed into icebergs. [C] Larsen-C, the next segment to the south, is losing mass on its underside. This ice loss is likely a result of the 2.5°C (4.5°F) temperature increase in the peninsula region in the last 50 years. [D] In response to the increasing warmth, the Antarctic Peninsula is sporting new vegetation growth, reduced sea ice, and disruption of penguin feeding, nesting, and fledging activities.
A loss of polar ice mass, augmented by melting of alpine and mountain glaciers (which experienced more than a 30% decrease in overall ice mass during the last century) will affect sea-level rise. The IPCC assessment states that "between one-third to one-half of the existing mountain glacier mass could disappear over the next hundred years." Also, "there is conclusive evidence for a worldwide recession of mountain glaciers ... This is among the clearest and best evidence for a change in energy balance at the Earth’s surface since the end of the 19th century."
Unfortunately, the new measurements of Greenland’s ice loss acceleration did not reach the IPCC in time for its report. Scientists are considering at least a 1.2 m (3.94 ft) high case for estimates of sea-level rise this century as more realistic given Greenland’s present losses coupled with mountain glacial ice losses worldwide. According to Rahmstorf and colleagues, the data now available raise concerns that the climate system, in particular sea level, may be responding more quickly than climate models indicate.... The rate of sea-level rise for the past 20 years is 25% faster than the rate of rise in any 20-year period in the preceding 115 years. . . . Since 1990, the observed sea level has been rising faster than the rise projected by models. These increases would continue beyond 2100 even if greenhouse gas concentrations were stabilized.
A quick survey of world coastlines shows that even a moderate rise could bring changes of unparalleled proportions. At stake are the river deltas, lowland coastal farming valleys, and low-lying mainland areas, all contending with high water, high tides, and higher storm surges. Particularly tragic social and economic consequences will affect small island states—which are unable to adjust within their present country boundaries—disruption of biological systems, loss of biodiversity, reduction in water resources, and evacuation of residents among the impacts there. There could be both internal and international migrations of affected human populations, spread over decades, as people move away from coastal flooding from the sea-level rise.
According to paragraph 7, why will people move away from the coastlines in the future?
选项
A、It will be too warm for them to live there.
B、The coastlines will have too much vegetation.
C、Flooding will destroy the coastal areas.
D、No agricultural crops will be grown on the coasts.
答案
C
解析
"... people move away from coastal flooding from the sea-level rise." Choice A is not correct because the temperature on land is not mentioned. Choice B is not correct because the vegetation along the coastlines will die as seawater floods it. Choice D is true, but it is not the reason why people will migrate.
转载请注明原文地址:https://kaotiyun.com/show/RtfO777K
0
托福(TOEFL)
相关试题推荐
Whichattitudeisassociatedwiththefollowingpeopleduringtheconversation?ChooseSIXanswersfromtheboxandwritetheco
Whichattitudeisassociatedwiththefollowingpeopleduringtheconversation?ChooseSIXanswersfromtheboxandwritetheco
Whichattitudeisassociatedwiththefollowingpeopleduringtheconversation?ChooseSIXanswersfromtheboxandwritetheco
Choosethecorrectletter,A,BorC.Newsreportscoveringthenewpoolexpressedconcernsover
Completethenotesbelow.WriteONEWORDONLYforeachanswer.DevelopmentStudiesDevelopmentStudiesattemptstounderstand-
Researchonweb-basedcrosswordsLilaandJakechangedthedesignoftheoriginalquestionnairebecause
WriteONEWORDONLYforeachanswer.Sophiethinksshowingherpassionfor_______mighthelpduringherinterview.
PatentsandInventionsWhenaninventionismade,theinventorhasthreepossiblecoursesofactionopentohim:first,hec
PatentsandInventionsWhenaninventionismade,theinventorhasthreepossiblecoursesofactionopentohim:first,hec
PatentsandInventionsWhenaninventionismade,theinventorhasthreepossiblecoursesofactionopentohim:first,hec
随机试题
Twopeoplehadmetthebusinessman,but______recognizedhim.
多器官功能障碍综合征(MODS)时为什么最先出现肺功能障碍?
尿甜,并散发烂苹果气味者,多见于
患者,男,49岁。因肝硬化门静脉高压症而引起食管静脉曲张破裂出血,经垂体后叶素等缩血管药物治疗后缓解。但病人出现雷诺现象及致下肢缺血等垂体后叶素的副作用。该患者应选用下列何种药物对抗
权责一致是社会主义法治理念的要求,也是行政法的基本原则。下列哪些做法是权责一致的直接体现?(2011—卷二—76,多)
黄曲霉毒素解释正确的有()。[河北省2008年5月三级真题]
以下关于兼职的说法错误的是()
简述公司投资融资资本类型。
简述科学技术对法律的影响。(2010法简31)
以太网中,当数据传输提高时,帧的发送时间要按比例缩短,这样有可能会影响冲突的检测。为了能有效地检测冲突,可以(1)或者(2)。快速以太网仍然遵循CSMA/CD,它采取(3)而将最大电缆长度减少到100m的方式,使以太网的数据传输速率提高到100Mb/s。
最新回复
(
0
)