2020秋高中英语Unit4GlobalwarmingSectionⅠWarmingUpReading学案含解析新人教版选修6

Unit4Unit4GlobalwarmingGlobalwarming全球变暖早已成为不争的事实，并且有加剧的趋势。那么这会对北极地区造成什么样的影响呢？Anearlyice­freeArcticOceaninsummermayhappenthreetimessoonerthanscientistshaveassessed.NewresearchsaystheArcticmightlosemostofitsicecoverinsummerinasfewas30yearsinsteadoftheendofthecentury.TheamountoftheArcticOceancoveredbyiceattheendofsummerbythencouldbeonlyaboutonemillionsquarekilometres.That'scomparedwithtoday'siceextent(范围)of4.6millionsquarekilometres—somuchmoreopenwatercouldbeaboonforshippingandforextracting(开采)mineralsandoilfromtheseabed,butitraisesthequestionofecosystemchange.WhiletheIntergovernmentalPanelonClimateChangein2007assessedwhatmighthappenintheArcticinthefuturebasedonresultsfrommorethanadozenglobalclimatemodels,tworesearcherssaidthatdramaticdropsintheextentoficeattheendofsummerin2007and2008calledforadifferentapproach.Outofthe23modelsnowavailable,thenewpredictionsarebasedonthesixmostsuitedforassessingseaice,accordingtoMuyinWang,auniversityofWashingtonclimatescientist,andJamesOverland,anoceanogr