资源描述:
《高中英语 VOA常速听力2012年11月合辑(文本)Global-Warming-Might-Threaten-Water-Supply素材.doc》由会员上传分享,免费在线阅读,更多相关内容在教育资源-天天文库。
1、VOA常速英语听力2012年11月合辑(文本):Global-Warming-Might-Threaten-Water-SupplyRosanneSkirbleNovember11,2012Globalwarmingoverthenextcenturycouldsignificantlyreducetheamountofwintersnowpackinmountainousareasinthenorthernhemisphere,accordingtoanewstudypublishedinNatureClimateChange.Seasonalsnowpackmeltisa
2、nessentialsourceoffreshwater,anditslosscouldthreatendrinkingwatersupplies,agriculturalirrigationandwildlifeecosystems.StanfordUniversityclimateexpertNoahDiffenbaughledthestudy,whichcomparessnowpackconditionsacrossthenorthernhemisphereinthelate20thcenturywithclimatemodelprojectionsforthenext
3、onehundredyears.DeceasingsnowpackThoseprojectionsarebasedonarangeofscenarioswhichforeseeariseinaverageglobaltemperaturesofbetweentwoandfourdegreesCelsius.ThestudyconcludesthataveragesnowaccumulationwilldecreaseinmostregionsoftheWesternUnitedStates,Europe,CentralAsiaandtheHimalayas,comparedt
4、ohistoricalpatterns.Itprojectsthatlowandextremelylowsnowfallswouldexceedthelowsofthelater20thcenturybetween10and30percentofthetimewithtwodegreesofwarming.And,Diffenbaughsays,"Iftheplanetwarmsby4degreesCelsius,theUnitedcouldexperiencesnowpackaccumulationsbelowthelevelsofthelate20thcenturyupt
5、o80percentoftheyears.”Thestoryisthesameinotherpartsofthenorthernhemisphere,wheresnowpackisanatural,andcritical,waterreservoir.WaterworriesThestudyfindsthatanearlyspringmeltwouldbringmorewaterintothewatershedsoonerthanusual,potentiallyfloodingrivers,lakesandartificiallydammed-river-3-reservo
6、irs.Andwithlesswateravailablelaterintheseason,chancesformorewildfires,pests,andspeciesextinctionsincrease.Diffenbaughsaysthistimingwouldalsoexacerbatedroughtconditionswhenthedemandforwaterisgreatest.“Wecaninferthatshouldthesephysicalclimatechangesoccurinthefuture,thattherewouldbeimpactsonwa
7、tersupplyforagricultureandforhumanconsumptionandfornaturalecosystemsifthewaterstorageandmanagementsystemsarenotadaptedtothosechanges.”Accordingtoclimatemodels,extremeraineventsareexpectedtoincreaseastheplanetwarms.However,Diffenbaughsays,thatwon’tchangeh