《經(jīng)濟(jì)學(xué)專業(yè)英語教程（第四版 下）》課件Unit 4

Unit4Text:EnvironmentalProtection（環(huán)境保護(hù)）1.Keywords2.Externality3.Formsofenvironmentalpollution4.Causesforenvironmentalpollution5.Controlsofenvironmentalpollution6.Questions1.Keywordsenvironmentalpollutionone-wayexternalityuncompensateddamageindustrialestablishmentmarginalutilityorganicsewageself-purification.atmosphericpollutionpollutioncontrolnoxiousdischargesbodyofwaterpollutionabatementwaterpurificationwatercleanlinessmarginalbenefitmarginalcostinternalizingtheexternalitiesbiochemicaloxygendemand2.ExternalityAsituationinwhichactionbyoneconsumerorproducerconfersbenefitorinflictsdamageonanotherconsumerorproducerissaidtoinvolveexternalities.Environmentalpollutiontypicallyinvolvesone-wayexternality,inwhichtheactionsofoneproducerorconsumerinflictuncompensateddamageonotherproducersandconsumers.3.Formsofenvironmentalpollution3.1Airpollution3.2Waterpollution3.3Accumulationofsolidwastes3.4Noisepollution3.1AirpollutionThisisthedischargeofnoxiousgasesandsolidparticlesintotheatmosphere,leadingto“smog”conditionsinmanymetropolitanareas.3.2WaterpollutionThistypeofpollutionarisesfromdischargeoforganicandinorganicwastesintostreamsandlakes.3.3AccumulationofsolidwastesTheautomobilejunkyardisthemostconspicuousexample.3.4NoisepollutionThisisalevelofbackgroundnoisethatcanrangefrommildlyunpleasanttoliterallydeafening.4.CausesforenvironmentalpollutionWiththegrowthofpopulationandproduction,cleanairandpurewaterhavebecomescarcegoods,particularlyinthemetropolitanareaswheremostofthepopulationresides.Naturalprocessescannolongercopeunaidedwiththeflowofwastematerials,andtheenvironmentcanbecomeoverloadedtoadegreethatproducespermanentdeterioration.Dischargeofplantnutrientsintoalakecanstimulatethegrowthofweedsandalgaetothepointwherethelakefillsupwithsolidmatter.Heavydischargeoforganicsewageintoarivercanreducetheoxygencontentofthewatertothepointwhereitbecomesadeadstream,incapableofsupportingfishorotherlifeandincapableofselfpurification.Atmosphericpollutioninourlargercitiescouldreachthepointatwhichlifeintheseareaswouldbecomeimpossible.5.Controlsofenvironmentalpollution5.1Damagecreatedbywaterpollution5.2Socialbenefitsfrompollutionreduction5.3Socialcostsfrompollutionreduction5.4Conclusion5.1DamagecreatedbywaterpollutionCommunitieslocateddownstreamhavetospendmoreonwaterpurificationtomakethewatersafeandpalatable.Industrieslocateddownstreammayalsohavetospendmoneyonraisingwaterqualitytothelevelneededfortheiroperations.Fishlifemaybedamaged.Boatingandswimmingmaybeprevented.Debrisandodorsmayreducetheattractivenessofrecreationalareas.5.2SocialbenefitsfrompollutionreductionThemarginalbenefitofa1percentimprovementincleanlinessdeclinesasthecleanlinesslevelrises.Risingcleanlinessfrom20to21percentwillyieldmorebenefitthanraisingitfrom85to86percent.5.3SocialcostsfrompollutionreductionPollutionabatementalsorequiresuseofeconomicresources.Eitherproductionprocesseshavetobechanged,equipmentmustbeinstalledtoreducewastedischarges,orwaterpurificationsystemsmustbeconstructedtocleanupafterthefact.Thistakeslaborandcapital;andthisisasocialcost,regardlessofwhopaysthemoneycost.Itisreasonabletoexpectthatthecostofanadditionalunitofcleanlinesswillriseasmoreandmorecleanlinessisproduced.5.4ConclusionThelevelofwaterqualityshouldberaisedsolongasthemarginalbenefitfromfurtherimprovementexceedsthemarginalcostofachievingit.Thegapbetweenprivateandsocialcostiseliminated.Thisiscalled“internalizingtheexternalities.”6.Questions(1)Whatispollution?Whichformofpollutiondoyoufindthemostseriousaroundyou?(2)Whydoessuchpollutionaroundyouoccur?(3)Animportantissueindevelopingenvironmentalcontrolishowpurewewanttheairorwatertobe.Explainhoweconomicanalysis