The Population Bomb.docx
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The Population Bomb.docx
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ThePopulationBomb
UNIT8
TextA
PRE-READINGTASK
Exercise1
Beforereadingthepassage,trytoanswerthequestions.
1.Howmanyyearsdoyouthinkittakestodoubletheworldpopulationnow?
2.Whatmightbethepossiblesolutionstothepopulationexplosionintheworld?
Nowcompareyouranswerswithyourneighbours'.
ThePopulationBomb
I.Toomanypeople
1Figureandnumerousfactsprovethattherearealready,andcertainlythattherewillbe,toomanypeople.Simplycalculatingthelengthsoftimenecessarytodoubletheworld'spopulationisinstructive.Impressively,thetimerequiredgrowsevershorter:
6000yearsbeforeChrist,1000000yearswerenecessarytodoublethepopulation,thenabout1650yearsafterChristonly1000aroundthe1850's200years,in193080years.Currently,theworld'spopulationdoublesevery37years.
2Whatwouldhappenifthepopulationweretocontinuedoublinginvolumeevery37years?
3Accordingtorecentcalculations,maintainingsucharhythmofgrowthwouldresultin60millionbillionpeopleontheearthin900years,whichrepresents120inhabitantspersquaremeter.
4Optimistsbelieveandoftenassertthatsciencewillindeedfindsolutionstotheproblemofovercrowding,namelybyprovidingthemeanstoimmigratetootherplanets.Butthissolutionistotallyimpossible.Ineffect,evenifitshouldbecomepossible,50yearswouldbesufficientforthe60millionbillionpersonstomultiplytothepointofpopulatingVenus,Mercury,Mars,theMoonandthesatellitesofJupiterandSaturnwithadensityequaltothatoftheEarth.
II.FoodShortage
5Today,agoodpartofhumanitysuffersfrommalnutritionorfromundernourishment.
6Somethinkthattherecentscientificdiscoveriesappliedtoagricultureandknownunderthenameof"greenrevolution"willresolvetheproblem.Nothingislesscertain.Promotersoftherevolutionthemselvesbelievethatitcanofferonlyarespiteoftenortwentyyears.
7Inunderdevel-opedcountries,al-thoughmostlyagri-cultural,thelaginfoodproductioninrelationtopopulationgrowthincreasesmoreandmore.Asthecrisisworsensthesecountrieswillhavetoimportfood.Butfromwhere?
III.ADyingPlanet
8Theworld'spopulationexplosionisthesourceofawholeseriesofenvironmentaldeteriorations,whichintimecanhavedisastrousconsequences.
9Becausethepopulation-foodimbalancemakesitnecessarytoincreaseagriculturalproduction"atanyprice",methodsoftenharmfultotheenvironmentareusedwithoutjudgment.Forexample,theconstructionofhugedamstoirrigatehundredsofthousandsofacrescaninfactprovokecatastrophes.Thus,theAswanDamcurrentlypreventsthedepositoffertilesiltsbroughteachyearbythefloodingoftheNile.TheresultwillobviouslybeadecreaseinthefertilityoftheDeltalands.DammingtheMekongrisksthesameconsequencesforVietnamandneighbouringcountries.
10Fertilizers,syntheticpesticides,DDTcanbedevastating,transformingcomplexecosystems,necessaryfortheconservationoftheenvironment,intosimpleecosystems.
11Certainsituationsareperceivedasdangerousonlywhentheybecomecriticalenoughtocausenumerousdeaths.Smogisanexample.InLondonin1952itcausedsome4000deaths.Thisincidentprovokedanawakeningofconscienceandresultedindecisionswhichhaveproveneffective.Butsmogpresentsstillotherdangers:
namely,itdestroysplantswhichofferlittleresistance,andwhoseoxygenproductionisindispensabletous,anditchangestheearth'sthermalequilibrium.
12Fortheseformsofpollutionasforalltheothers,thedestructivechainofcauseandeffectgoesbacktoaprimecause:
"toomanycars,toomanyfactories,toomanydetergents,toomanypesticides,moreandmoretrailsleftbysupersonicjets,inadequatemethodsfordisinfectingsewers,toolittlewater,toomuchcarbonmonoxide.Thecauseisalwaysthesame:
toomanypeopleontheearth."
NewWords
numerous
a.many许多的,众多的
instruct
v.1.教,教育
2.通知,向…提供事实情况
instructive
a.1.有启发的,有教益的
2.教育的,指导性的
impressive
a.causingadmirationbygivingoneafeelingofimportance给人以深刻印象的
impressively
ad.给人以深刻印象地
namely
ad.(and)thatis(tosay)即,那就是
immigrate
v.tocomeintoacountrytomakeone'slifeandhomethere移居,移入
multiply
v.toincrease增加
populate
v.(ofagroup)tolivein(aparticulararea)(大批地)居住于,生活于
satellite
n.1.aheavenlybody,movingaroundalargerone卫星
2.aman-madeobjectintendedtomovearoundtheearth,moon,etc.人造卫星
density
n.1.密集,稠密
2.密度
undernourishment
n.营养不足
respite
n.(ashortperiodof)pauseorrest,duringatimeofgreateffort,pain,ortrouble暂缓,暂停
lag
n.aperiodoftimebywhichsomethingisslowerorlater落后,滞后
worsen
v.to(causeto)becomeworse变得更差,恶化
deterioration
n.thestateofbecomingworse恶化,变坏
judgment
n.theabilitytojudgecorrectly判断
dam
n.awallorbankbuilttokeepbackwater坝,堤
v.tobuildadamacross筑坝
irrigate
v.tosupplywaterto(dryland)灌溉
acre
n.ameasureofland,about4047squaremetres英亩(≈4047平方米)
provoke
v.tocause引起
catastrophe
n.asudden,unexpected,andterribleeventthatcausesgreatsuffering灾难
fertile
a.(ofland)whichproducesgoodcrops肥沃的
silt
n.(水流夹带或水底沉积的)泥沙,淤泥
fertility
n.theconditionorstateofbeingfertile肥沃,丰产
delta
(河流的)三角洲
synthetic
a.1.合成的
2.综合的
pesticide
n.农药,杀虫剂
transformv.tochangecompletelyinform,appearance使改变(性质等)
ecosystem
n.生态系统
awakening
n.theactofbecomingconsciousorconcerned觉醒,唤醒
resistance
n.theabilityorpowerofresisting抵抗力
oxygen
n.氧,氧气
indispensable
a.thatistooimportanttolivewithout必不可少的
destructive
a.破坏性的,毁灭性的
detergent
n.achemicalproductusedforcleaning洗涤剂
trail
n.aseriesofmarksleftbyapersonorthingpassingby痕迹
supersonic
a.fasterthanthespeedofsound超音速的
adequate
a.sufficient充分的,足够的
inadequate
a.notadequate不适当的,不充分的
disinfect
v.消毒,杀菌
carbon
n.碳
monoxide
n.一氧化物
PhrasesandExpressions
ineffect
实际上,实质上
beequalto
等于,比得上
underthenameof
名叫,称为
sufferfrom
遭受
inrelationto
与…相比,与…有关,涉及
intime
最终,迟早,及时
atanyprice
不惜任何代价
ProperNames
beforeChrist
公元前
Venus
金星
Mercury
水星
Mars
火星
Saturn
土星
theAswanDam
阿斯旺水坝
theNile
尼罗河
theMekong
湄公河
Vietnam
越南
DDT
滴滴涕(商品名,一种杀虫剂)
TextB
PRE-READINGTASK
Exercise1
Beforereadingthepassage,thinkaboutthequestions.
1.Whatwoulditbelikeiftherewerenotreesontheearth?
2.Whyisitimportantforustoplantmoretreesnowadays?
Nowreadthepassageandcheckyouranswerswiththeauthor's.
ReforesttheEarth!
1Throughoutthedrought-riddensummerof1988,theworldheardmuchabouthowtheburningoffossilfuelscausesthegreenhouseeffect(therapidwarmingoftheearth'satmosphere.)Weheardlittleabouthowtheburningoftropicalrainforestsalsocontributestothegreenhouseeffect.Andstilllessdowehearabouthowreforestationofthesetropicscouldhelphealanailingworld.
2Theearthconstantlymaintains700billionmetrictonsofcarbondioxide(CO2)intheatmosphere.Fossilfuelsemitanother5.2billionmetrictonsofCO2intotheaireachyear,whiletheburningoftropicalforestsemitsroughly1.8billionmetrictonsofCO2--bothcontributingtoabuildupofcarbondioxidethatwillsoontriggerthegreenhouseeffect.TheCO2gasestraptheheatofthesuninthesamewaytheglassofagreenhousecontrolstemperatureforplants.Ifthegasesbecometooconcentrated,toomuchheatwillcollect,resultinginrisingtemperatures.
3Ofallthecarbondioxideemittedintotheatmosphere,onlyabouthalfaccumulatesintheskieswhiletherestdisappearsintooceansandlakes,vegetationandsoil.Sooutofthe5.2billionmetrictonsofCO2emittedfromtheburningoffossilfuelsandthe1.8billionmetrictonsreleasedfromtheburningofrainforestseachyear,only3.5billionmetrictonscontributestoglobalwarming.
4In1980,36000squaremilesofforestwereburnedinthetropics.In1987,33000squaremilesofrainforestwereburnedinBrazilianAmazoniaalone.Bytheyear2020thefigurefortropical-forestemissionsofCO2couldclimbtoanother5billionmetrictons.Asaresult,theCO2releasedintotheatmosphereeachyearwouldrisetoapproximately10.2billionmetrictons.
5Replantingtreesinthetropicscouldeventuallyofferasolutiontothegreenhouseeffect.Atreeabsorbscarbondioxidethroughphotosynthesis.Plantenoughtrees(asmanyas250billion)andwecouldremovemuchoftheadditionalCO2buildingupintheatmosphere.Nowhereintheworldareconditionsbetterforgrowingtreesthaninthetropics,whereyear-roundwarmthandmoistureencouragerapidgrowth.Tostartagrand-scaletree-growingprojectinthetropics,however,wouldrequireasmanyas20governmentsinLatinAmerica,Africa,andAsiatostoptherapiddestructionofrainforests.
6Howmanytreeswouldweneedtoreforesttheearthandstabilizethedamageproducedbyglobalwarming?
Oneacreofatropicalplantationcanabsorbanannualaverageoffourmetrictonsofatmosphericcarbon.Inordertosoakup1billionmetrictonsofCO2,wewouldhavetoplant400000squaremilesofnewtropicalforests.Toeliminatethebuildupof3.5billionmetrictonswouldrequireplantingtreeson1.2millionsquaremiles,anexpanseroughlyequivalenttoallstateseastoftheMississippi.
7Wherecanwefindenoughspacetoreplantwhatisn'tbeingotherwiseutilized?
Inthehumidtropicsforestshavebeencutdowninwatershedregionswherereplantingisurgentlyneededtostop
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