《臭氧层空洞》PPT课件

Lesson3,ShipsintheDesertAlGore,Theintroductionofthetext:,ObjectivesofTeaching,TocomprehendthewholetextToleanandmasterthevocabularyandexpressionsTolearntoparaphrasethedifficultsentencesTounderstandthestructureofthetextToappreciatethestyleandrhetoricofthepassage.,1.Introductionabouttheauthor,AlGorewasbornin1948inWashingtonD.C.,U.S.HehasbeenaSenator(1984-1992)representingtheStateofTennessee,andU.S.Vice-President(1992-2000)underPresidentBillClinton.HeranforthePresidencyagainstGeorgeW.Bushjr.butthelatterwonthecloselytiedelectionandhasbecomethe43rdAmericanPresident.ThetextistakenfromAlGoresbookEarthintheBalance,AlGoresprofoundanalysisofwherehumanityhasgonewrongrangesacrosshistory,politics,science,economics,psychology,philosophy,andreligion.,Goredemonstratesthatthequalityofourairandwaterisurgentlyatrisk.Heclearlyillustrateshowproblemsthatoncewereregionalhavenowbecomeglobal.Gorearguesforaworldwidemobilizationtosaveusfromdisaster.,2.Detailedstudyofthetext,ShipsintheDesertWhatsthemeaningofthetitle?Whatdoestheauthortrytotellusthroughhisarticle?,Para.1typicalexampleofenvironmentaldestruction,WhydidthewritergototheAralSea?Whatdidheseethere?,theprospectsofagoodcatchlookedbleak:,agoodcatchdidnotlookpromising/hopeful.anunderstatement,theAralsea,TheAralSea:*locatedinUzbekistanandKazakhstan*historicallyasalinelake*In1960theworldsfourthlargestlake,thesizeoftheentiretyofSouthernCalifornia*inthecenterofalarge,flatdesertbasinaprimeexampleofadynamicenvironment,AmericasGreatLakes,*thegroupoffivefreshwaterlakes,centralNorthAmerica,betweentheUnitedStatesandCanada,largestbodyoffreshwaterintheworldFromwesttoeast,theyareLakeSuperior,LakeMichigan,LakeHuron,LakeErie,andLakeOntarioHOMESHstandsforHuron,OforOntario,MforMichigan,EforErieandSforSuperior.,comparable:,somethingthatiscomparabletosomethingelseisa)asgoodas/asbigas/asimportantastheotherthing;b)similartotheotherthinge.g.ThisdinneriscomparabletothebestFrenchcooking.,tofeedithasbeendivertedinanill-consideredirrigationschemetogrowcottoninthedessert:,toflowintotheseahasbeenturnedawaytoirrigatethelandcreatedinthedeserttogrowcotton.Theschemewasanill-conceivedonebecauseitfailedtotakeintoconsiderationtheecologicaleffect.,Para.2thesisstatement:,Mysearchfortheunderlyingcausesoftheenvironmentalcrisishasletmetotravelaroundtheworldtocheckandstudycasesinordertofindoutthebasiccausesbehindtheenvironmentalcrisis,Whatdoesitmean?,ItraveledaroundtheworldbecauseIwantedtosee,checkandstudycasesofsuchdestructioninordertofindoutthebasiccausesbehindtheenvironmentalcrisis.Thissentenceexpressesthemainideaandindicatingthedevelopmentofacausalessay.,Trans-AntarcticMountains,Antarcticaisicycold.Trans-AntarcticMountainsdivideditintotheEastAntarcticandWestAntarcticsubcontinents.,Chinahassetuptwoscientificresearchstationsthere:ZongshanStationintheEastandGreatWallintheWest.,thesunglaringatmidnightthroughaholeinthesky,thesunshiningatmidnightthroughtheozonedepletionahole:ozonedepletion臭氧层空洞,aboutthetunnelhewasdiggingthroughtime:,aboutthetunnelhewasdrillingforsamplesfromtheglacier,whichestimatesthetime.Thedeeperhedrilled,thefartherthesampleintime;inotherwords,thesurfaceoftheglacierisanindicationofrecenttimewhilethedeeperpartoftheglaciertellsofsituationofamuchmoreremoteperiod.,Hemovedhisfingerbackintimetotheiceoftwodecadesago:,Followingthelayersoficeinthecoresample,hisfingercametotheplacewherethelayeroficewasformed20yearsago.,CleanAirAct:,AmericanCongresspassedtheCleanAirActin1970,whichisoneoftheoldestenvironmentallawsoftheU.S.aswellasthemostfar-reaching,thecostliest,andthemostcontroversial.,twocontinents,SouthAmericaandAntarcticaleastaccessibleplaceonearth:theplacewhichisthemostdifficulttogettointheworld,Para.3theglobalwarmingseenintheAntarctic,WhatsParagraph3talkingabout?,Whatsthecauseoftheglobalwarming?,Beganwiththeindustrialrevolution,Industrymeantcoal:,thedevelopmentofindustrymeanttheuseoflargeamountofcoalasfueltogeneratepower.,-bringingrisingwithitsabilitywarmtheearth:,adverbialofresult:makingtheamountofcarbondioxideintheatmospheregrow;heatcannoteasilygetthroughcarbondioxideandgointothehighaltitudesocarbondioxideplaystheroleofacover,keepingtheheatneartheearth.,upwindfromtheicerunawayscientistsmonitortheairtochartthecourseofthatinexorablechange:,upwindfromtheicerunawaywheretheskiplanelandsandkeepsitsenginesrunningsothatthemetalpartswillnotbefrozensolid,scientistswatchtheairseveraltimeseverydaytomarkthecourseofthatunalterablechange.upwind:inthedirectionfromwhichthewindisblowingorusuallyblowstochartthecourse:toshowtheonwardmovementonanoutlinemap,graph:usuallyamathematicaldiagram,Para.4athinningcapastheresultofArcticairwarms,Whatcausedthethinningofthepolaricecap?,globalwarming,snowmobile,akindofmotorvehiclefortravelingoversnow,usuallywithsteerablerunnersatthefrontandtractortreadsattherearrendezvouspoint:theplacewhereasubmarinewastopickthemupArendezvousisaplacewhereyouhavearrangedtomeetsomebodyoftensecretly.,tosecurethereleaseofpreviouslytopsecretdata:,toensurethemakingpublicofdatawhichwasoriginallyclassifiedastopsecret.,sonar:,U(anacronymforsoundnavigationranging)anapparatususingsoundwavesforfindingthepositionofunderwaterobjects,suchasminesorsubmarines声纳（利用声波探测如水雷或潜艇等的水底目标的仪器）Baiqidolphinshavesonar.Batshavesonar.,Iwasstandingwhenseparatesheetscollide:,Iwasstandinginthevastsceneofsnowwhichwasfearfullybeautiful,windsweptandshiningwhite,withthestretchoficefieldcharacterizedbysmallridgesbecauseoftheforceofthecollisionoftheseparatelayers.eerily:mysteriously,especiallyinsuchawayastofrightenordisturbsnowscape:sceneofsnow.cf.landscapeandseascape.,theconsequencesofathinningcapcouldbedisastrous:,theresultofathinningcapmayindicatethepossibilitiesofdisasterscould:thewordindicates“possibilities”,Andwhycouldthethinningofthepolaricecapbedisastroustotheworld?,Becausethepolarcapplaysanimportantroleintheworldsweathersystem,theconsequencesofathinningcapcouldbringaboutdramaticchangesintheecologicalpattern.Forexample,itwillbringlargeamountofwaterwhichwillraisetheoceanlevelandcausesomefloods.,Para.5therisingtemperatureoftheearth,.Consideringsuchscenariosisnotapurelyspeculativeexercise:ThinkingabouthowaseriesofeventsmighthappenasaconsequenceofthethinningofthePolarcapisnotjustakindofpracticeinspeculation,ithasgotpracticalvalue.,thepatternoficedistributioncontroversialclaim:,theregularwayiceisdistributedastatementwhichsomescientistsstilldonotcompletelyaccept,theArcticCircle,animaginarylinedrawnroundtheworldatacertaindistancefromthemostnorthernpoint(theNorthPole),northofwhichthereisnodarknessforsixmonthsofeachyearandalmostnolightfortheothersixmonths.cf.theAntarcticCircletundra:anyofthevast,nearlylevel,treelessplainsoftheArcticregions,Para.6theimagesofdestructionattheequator,billowing:,largeswellingmassofbillowv.Whensmokeorcloudbillows,itmovesslowlyupwardsoracrossthesky,Amazonrainforest,TheBrazilianAmazoncontainsaboutathirdoftheEarthsremainingtropicalforestandaveryhighportionofitsbiologicaldiversity.Onehectare(2.47acres)ofAmazonianmoistforestcontainsmoreplantspeciesthanallofEurope.Yetstillitisbeingdestroyedjustlikeotherrainforestsaroundtheworld.,fastpastureforfast-foodbeef:,Bitbybittreesintherainforestarefelledandthelandisclearedandturnedintopasturewherecattlecanberaisedquicklyandslaughteredandthebeefcanbeusedinhamburgers.fastpastureforfast-foodbeef:alliterationPayattentiontotheconnectionofthetwo“fasts”infastpastureandfastfood.Withthatcomesthe“fast”disappearanceoftherainforest.,thedryseason:,hewetseasontherainyseasonsimilarly:thefootballseason,thebreedingseason,theplantingseason,theholidayseason,theharvestseason,thecoldseason,thetouristseason,thegameseason,aseasonoffilminseason:Ant.beoutofseasonseasonv.e.g.seasonthefoodwithsalt,withmorethanoneTennesseesworthofrainforest,theareaofrainforestburnedinoneyearisbiggerthanthestateofTennessee.worth:equalinareaorsizeslash:cutwithasweepingstroke,wearesilencingthousandsofsongswehaveneverevenheard:,Sincemilesofforestarebeingdestroyedandthehabitatfortheserarebirdsnolongerexists,thousandsofbirdswhichwehavenotevenhadachancetoseewillbecomeextinct.,HowwillthedestructionoftheAmazonrainforestaffecttheearthsecologicalbalance?,Fewerrainforestsmeanlessrain,lessoxygenforustobreathe,andanincreasedthreatfromglobalwarming.,Para.7imagesofdestructionseenalmostanywhere,Whatdoesthewritercall“ghostsinthesky”?,“noctilucentclouds”,Howaretheyformed?,Theyareformedbecauseofthehugebuildupofmethanegasintheatmosphere,releasedfromlandfills,fromcoalminesandricepaddies,frombillionsoftermitesthatswarmthroughthefreshlycutforestland,fromtheburningofbiomassandfromavarietyofotherhumanactivities.,Onsomenightsthatsignalsthelossofecologicalbalancenowinprogress:,Onsomenights,intheareaatahighnorthernlatitude,theskyalonepresentsanotherexampleofillomenshowing.Thereisecologicalimbalanceandthiskindofimbalanceisdeveloping.inhighnorthernlatitude在北纬高纬度地区cf.longitude经度,This“luminouscloud”occasionallyappearswhentheearthisfirsthiddenintheeveningdarkness;shiningunsteadilyaboveuswithapartiallytransparentwhiteness,thesecloudsdontseemnatural,“noctilucentcloud”,noctilucentcloud:,nocti-meansnight;lucentmeansshining,translucentdesignatingorofaluminouscloudvisibleatnighttranslucent:partiallytransparent,landfills:garbagedisposal,methaneisemittedfromgarbagedisposal,fromcoalminesandricefields,frombillionsoftermites（白蚁）movinginlargenumbersthroughthefreshlycutforestland,fromtheburningofamountoflivingorganisminaparticularareaandfromavarietyofotherhumanactivities.,Eventhoughnoctilucentcloudstothesurfacefarbeneaththem,Theimplicationisthatthenightcomesearlierthantheupperpart.Thebalancebetweendayandnightisbroken.altitudes:ahighareae.g.Athighaltitudesitisdifficulttobreathe.,Para.8humanattitudestowardstheimagesofdestruction,Whatshouldwefeeltowardtheseghostsinthesky:Whatshouldourattitudebetowardthesenoctilucentcloudsinthesky?,themixofemotionswefeelatthezoo:,themixofemotionswefeelatthezoo:ontheonehandwefeelexcitedaboutseeingthoseanimals,butontheotherhand,wefeelsorryforthembecausetheyhavebeendeprivedoffreedom.Shoulditonlybeafeelingofsurpriseandadmirationoracombinationofdifferentfeelingsweexperienceinthezoo?,feelaweforourownpower:,feelamazedandfrightenedatourownpower.,upsetthebalancebetweendaylightanddarkness,Justasmenarekillingsuchlargenumberofelephantsfortheirtusksthatthespecieswillsoonextinguish,weareusinganddestroyingresourcesinsuchabigamountthatwearedisturbingthebalancebetweendaylightanddarkness.,greenhousegases,gasesthatwilltrapheatatthesurfaceoftheearthlikeagreenhouseandranksthirdonlytocarbondioxideandwatervaporintotalvolume.Thismeansofallthegases,watervaporoccupiesthelargestportion,carbondioxidethesecond.Methane-naturalgas,greenhousegases-thethird,thechemistryoftheupperatmosphere:,thechemicalcompositionoftheupperatmosphere,shouldntitstartleuswithaspectrallight?Orhaveoureyeshumancivilizationandtheearth?,tworhetoricalquestionsitshouldstartleus;oureyesshouldnothavenadjustedsocompletelytothebrightlightsofcivilizationthatwecantsee.,whattheyare,Orhavewebeensoaccustomedtothebrightelectriclightsthatwefailtounderstandthethreateningimplicationoftheseclouds,aphysicalmanifestationoftheviolentcollisionbetweenhumancivilizationandtheearth?,wefailtounderstandthatitisaglaringsignoftheviolentclashbetweenhumanactivityandnature?,Para9.humanspuzzlingresponse,Eventhoughitissometimeshardtoseetheirmeaning,wehavebynowallwitnessedsurprisingexperiences:tounderstandthethreatoftheseclouds,Whatarethesurprisingexperiencesthatsignalthedamagefromourassaultontheenvironmentmentionedintheparagraph?,morehotdays,quickersunburn,andmoredebateongarbagedisposingmatter.,-whetheritsthefrequencywithgrowingmountainsofwaste:,whetheritisthefactthatrecentlytherearemorehotdayswhenthetemperatureisover100degreesFahrenheit(=38degreeCelsius),orthefactthesunburnsourskinmorequicklyinrecenttimes,orthefactthatthedebateoverthewayofdisposingofthegrowingamountofwastemattercomesupmorefrequently.,Butourresponsetothesesignalsispuzzling:,Butourreactiontothesesignalsissobafflingthatitisdifficulttounderstand.,Tocomeatthequestionanotherway:,Toapproachthequestioninadifferentway;toputthequestiondifferently,Whyhaventwelaunchedamassiveefforttosaveourenvironment?,Whyhaventwestartedalarge-scalemovementtosaveourenvironment?,someimages,Whydosomesignssoalarmusthatweimmediatelytakeactionandconcentrateonwaysofdealingwiththemeffectively?someimages:e.g.whitepollution,(immediateaction:stopproducingsandstorm(immediateaction:plantgrassandtrees),otherimages.lesspainfuldistraction,Andwhydoothersigns,thoughsometimesnolessstriking,onlycauseakindoflossandinactivityandweconcentrateourattentionnotonthewaystodealwiththembutinstead,onsomeothersubstituteswhichareeasytogetandlesspainful?otherimages:e.g.gasesfromcars(distraction:peoplestillwantcars,andhaveaneasyandlesspainfulwaytodealwiththisissue,say,itsanaturalcycle,notbecauseofhumanactivities),Para.10theimportanceoforganizingourthoughts,itmaybehelpfultoclassifythemandthusbegintoorganizeourthoughtsandfeelingssothatwemaybeabletorespondappropriately:toarrangethemintodifferentgroupssothatwewillbeabletotakethemostsuitableaction.,Para.11themilitarysystem:“local”skirmishes,“regional”battles,and“strategic”conflicts,theater:sceneofoperatione.g.ThiswasthePacifictheatreofWorldWarII.这里是第二次世界大战的太平洋战区。lecturetheatre阶梯教室,Ausefulsystemcomesfromthemilitary,Ausefulwayofclassifyingcomesfromfighting.Theyare:“local”skirmish,“regional”battles,and“strategic”conflict.Askirmishisaminorbattle,aglobalcontext:,Thisthirdkindisreservedforstrugglesthatcanendangeranationsexistenceandmustbeviewedagainstthebackgroundoftheworld.,Whatkindofconflictwillbeconsideredas“strategic”conflict?,Onlystrugglethatcanthreatenanationssurvivalandmustbeunderstoodinaglobalcontextwillbeconsideredas“strategic”conflict.,Para12.thesamecasewiththeimagesofdestruction,illegalwastedumping:thedisposalofwasteinawaythatviolatesthelawProblemslikeacidrain,thecontaminationofundergroundaquifers,andlargeoilspillsarefundamentallyregional:basicallybelongtoregionalcategory.,Acidrain（酸雨）:,rainwithahighconcentrationofacidsproducedbysulfurdioxide(二氧化硫),nitrogenoxide(氧化氮),etc.emittedduringthecombustion（氧化）offossilfuels;ithasadestructiveeffectonplantandaquatic(水中的)life,buildings,etc.,contamination:,cf.pollution:Pollutionisatermtodescribethedegradingoftheenvironmentinsomewaytheairwebreatheorthewaterwedrinkorwashincanbepollutedwhenitiscontaminatedbysomeforeignorunwantedmaterial,e.g.engineoilorchemicalsinwater,smoke,orcarexhaustintheair.Wetalkaboutairpollutionorwaterpollutionnotwatercontaminationbut“pollution”isthemorecommonterm.,Contaminationisamorescientifictermusedtodescribeasubstancecontaminatingorspoilingsomethingsuchasanexperiment,e.g.thewaterpurityexperimentwascontaminatedbyanoutsidechemical.Wewouldnotsay“polluted”inthiscase.,aquifer:anundergroundlayerofporous(多孔的)rock,sand,etc,containingwater,intowhichwellscanbesunk.,thepatternappearstobeglobal:,Itseemsthattheproblemhasacquiredaglobalnaturesincesomanysimilarthingsoccuratthesametimeallovertheworld.,Para.13anewclassofenvironmentalproblemsaffectingtheglobalecologicalsystem:chlorine氯,The600percentincreasecountriesproducingthechlorofluorocarbonsresponsibleTherehavebeen600percentincreaseintheamountofchlorineintheatmosphereduringthelastfortyyearsnotonlyinthosecountrieswhicharemainlyresponsiblefortheproductionofCFCchlorofluorocarbons:CFC氟里昂,Theincreasedlevelsradiationfromthesun:,Theincreaseoftheamountofchlorinedisturbstheusualwayofhandlingandcontrollingtheamountofultravioletradiationtheearthreceivesfromthesun.,ultraviolet:,(oflight)thatisbeyondthepurpleendoftherangeofcolors(spectrum)thatmakeuplightthatcanbeseenbyhumanbeingsultravioletrays:紫外线ultra-:beyonde.g.ultrared（红外线的）,ultrashort（超短波的）,ultrasonic（超音波的）,ultramodern（极其现代化的）,Para.14anotherstrategicthreatglobalwarming,Why?Becausethisincreaseinheatseriouslythreatenstheglobalclimateequilibriumthatdeterminesthepatternofwinds,rainfall,surfacetemperatures,oceancurrentsandsealevel,andtheseinturndeterminethedistributionofvegetativeandanimallifeonlandandseaandhaveagreateffectonthelocationandpatternofhumansocieties,soitisconsideredastrategicthreat.,equilibriumthatdeterminesthepatternof:,balancethatdecidestheregularwayof.equilibrium:astateofbalancebetweenopposingforcespattern:aregular,mainlyunvaryingwayofmovement,Para.15thetransformedrelationshipbetweenhumankindandtheearth,inourowntimewehavereshapedalargepartoftheearthsfacewithconcreteinourcities:inthemoderntimewehavegivenanewshapeorformtoalargepartoftheearthssurfacebybuildingpavedroads,bridges,buildingsetc.concrete:metonymy,Butthesechangeshave,untilrecently,beenrelativelytrivialfactorsintheglobalecologicalsystem:,Althoughsometimesthesechangesseemtobetakingplaceeverywhereintheworldtheyhave,untilrecently,beenrelativelyinsignificantintheirinfluenceontheecologicalsystemoftheworld.pervasive:prevailing;spreading,thatassumptionsothat:,Whatweshouldgetridofisexactlythatkindofviewwhichhasbeentakenforgranted.Onlywhenwehavedroppedsuchaviewcanwethinkinalongterm,overallwayaboutourrelationshiptotheenvironment.,Para.16thedominantcauseofchangeintheglobalenvironmenthumancivilization,Whatcausedthechangeoftheentirerelationshipbetweenhumankindandtheearth?,humancivilization,Yetweresistthistruthagainstthemountains:,Yetwerefusetoacceptthistruefactandfinditdifficulttothinkthatweshouldtreatoureffectontheearththesamewayasthemoonsgravitationalpullontheoceansorthewindseffectonthemountainsandmeasureoureffectinthesamewayaswemeasuretheeffectofnaturalforces.,usethatpowerwisely,ofcausewemustrecognizethatwehavetheresponsibilitytousethenewlyacquiredcapabilityinaprudentwayandwithproperrestraint.,thefragilityoftheearthsnaturalsystems:,theearthsnaturalsystemsareverydelicateandcaneasilybedisrupted.,Para.17dramaticchangesintwokeyfactors,asuddenandstartlingsurgeinhumanpopulationasuddenaccelerationofthescientificandtechnologicalrevolution,thatdefinethephysicalrealityofourrelationshiptotheearth:,thatdeterminetheactualstateofourrelationshipwithnature.,withtheadditiononeChinasworthofpeople,Everytenyearsthenewly-addedpopulationwillequalthepopulationofChina