Unit-8-Focus-on-Global-Warming课文翻译综合教程二

1、Unit8FocusonGlobalWarmingJohnWeierTwenty-fiveyearsagoifyoumadeatriptothelocallibraryandperusedtheperiodicalsectionforarticlesonglobalwarming,you'dprobablyhavecomeupwithonlyafewabstractsfromhardcoresciencejournalsormaybeablurbinsomeesotericgeopoliticalmagazine.AsanInternetsearchonglobalwarmingnow

2、attests,thesubjecthasbecomeasrootedinourpublicconsciousnessasMadonna2ormicrowavecooking.1Perhapsallthisattentionisdeserved.Withthepossibleexceptionofanotherworldwar,giantasteroid,oranincurableplague,globalwarmingmaybethesinglelargestthreattoourplanet.2Fordecadeshumanfactoriesandcarshavespewedbillion

3、softonsofgreenhousegasesintotheatmosphere,andtheclimatehasbeguntoshowsomesignsofwarming.Manyseethisasaharbingerofwhatistocome.3Ifwedon'turbourgreenhousegasemissions,thenlow-lyingnationscouldbeawashinseawater,rainanddroughtpatternsacrosstheworldcouldchange,hurricanescouldbecomemorefrequent,andElN

4、inoscouldbecomemoreintense.OurWarmingPlanetWhathasworriedmanypeoplenowisthatoverthepast250yearshumanshavebeenartificiallyraisingtheconcentrationofgreenhousegasesintheatmosphere.Ourfactories,powerplants,andcarsburncoalandgasolineandspitoutaseeminglyendlessstreamofcarbondioxide.Weproducemillionsofpoun

5、dsofmethanebyallowingourtrashtodecomposeinlandfillsandbybreedinglargeherdsofmethane-belchingcattle.Nitrogen-basedfertilizers,whichweuseonnearlyallourcrops,releaseunnaturalamountsofnitrogenoxideintotheatmosphere.Oncethesecarbon-basedgreenhousegasesgetintotheatmosphere,theystaytherefordecadesorlonger.

6、AccordingtotheIntergovernmentalPanelonClimateChange(IPCC)sincetheindustrialrevolution,carbondioxidelevelshaveincreased31percentandmethanelevelshaveincreased151percent.Paleoclimatereadingstakenfromfossilrecordsshowthatthesegases,twoofthemostabundantgreenhousegases,areattheirhighestlevelsinthepast420,

7、000years.ManyscientistsfearthattheincreasedconcentrationsofgreenhousegaseshavepreventedadditionalthermalradiationfromleavingtheEarth.Inessence,thesegasesaretrappingexcessheatintheEarth'satmosphereinmuchthesamewaythatawindshieldtrapssolarenergythatentersacar.4Muchoftheavailableclimatedataappearto

8、backthesefears.5TemperaturedatagatheredfrommanydifferentsourcesallacrosstheglobeshowthatthesurfacetemperatureoftheEarth,whichincludestheloweratmosphereandthesurfaceoftheocean,hasrisendramaticallyoverseveraldecades.Worldwidemeasurementsofsealevelshowariseof0.1to0.2metersoverthelastcentury.That'sa

9、nincreaseofroUghly1every4,000years.Readingsgatheredfromglaciersrevealasteadyrecessionoftheworld'continentalglaciers.Takentogether,allofthesedatasuggestthatoverthelastcenturytheplanethasexperiencedthelargestincreaseinsurfacetemperaturein1,000years.Notsurprisingly,manyscientistsspeculatethatsuchch

10、angesintheclimatewillprobablyresultinhotterdaysandfewercooldays.6AccordingtotheIPCC,landsurfaceareaswillincreaseintemperatureoverthesummermonthsmuchmorethantheocean.Themid-latitudetohigh-latituderegionsintheNorthernHemisphereareassuchastheContinentalUnitedStates,Canada,andSiberiawilllikelywarmthemos

11、t.Theseregionscouldexceedmeanglobalwarmingbyasmuchas40percent.Asfarashumanhealthisconcerned,thosehithardestwillprobablyberesidentsofpoorercountriesthatdonothavethefundstofendagainstchangesinclimate.7Aslightincreaseinheatandraininequatorialregionswouldlikelysparkanincreaseinvector-bornediseasessuchas

12、malaria.Moreintenserainsandhurricanescouldcausemoreseverefloodingandmoredeathsincoastalregionsandalongriverbeds.Evenamoderateriseinsealevelcouldthreatenthecoastlinesoflow-lyingislandssuchastheMaldives.Allacrosstheglobe,hottersummerscouldleadtomorecasesofheatstrokeanddeathsamongthosewhoarevulnerable,

13、suchasolderpeoplewithheartproblems.Thewarmertemperaturesmayalsoleadtohigherlevelsofnear-surfaceozonefromcarsandfactories,whichwouldlikelycausemoreperilousairqualitydaysandhospitaladmissionsforthosewithrespiratoryproblems.TakingActionsFortunately,wecantakeactionstoslowdownglobalwarming.8Globalwarming

14、resultsprimarilyfromhumanactivitiesthatreleaseheat-trappinggasesandparticlesintotheair.Themostimportantcausesincludetheburningoffossilfuelssuchascoal,gas,andoil,anddeforestation.Toreducetheemissionofheat-trappinggaseslikecarbondioxide,methane,andnitrousoxides,wecancurbourconsumptionoffossilfuels,use

15、technologiesthatreducetheamountofemissionswhereverpossible,andprotecttheforestsintheworld.Wecanalsodothingstomitigatetheimpactsofglobalwarmingandadapttothosemostlikelytooccur,9e.g.,throughcarefulplanningandotherstrategiesthatreduceourvulnerabilitytoglobalwarming.Butwecan'stopthere.Wearealsoadvoc

16、atingpoliciesthatwillcombatglobalwarmingoverthelongterm,thingslikecleancarsthatrunonalternativefuels,environmentallyresponsiblerenewableenergytechnologies,andstoppingtheclear-cuttingofvaluableforests.Clearly,globalwarmingisahugeproblem.Itwilltakeeveryonegovernments,industry,communitiesandindividuals

17、workingtogethertomakearealdifference.Fortunatelyyoucanbepartofthem.关注全球气候变暖二十五年前，如果你想去当地的图书馆通过各种期刊搜索关于全球气候变暖的文章的话，很可能你只能找到一些刊登在核心自然科学期刊或非常专业的地理科学杂志上的同类文章的摘要。然而，当今因特网搜索结果表明全球气候变暖，就像麦当娜或微波炉一样，成为所有人都十分关心的话题。应该说公众对全球气候变暖的关注是很有必要的。除了一些可能的巨大灾害，例如新的世界大战、巨型小行星撞击地球、或是无法治愈的流行疾病等等，全球气候变暖可能是对地球的唯一最大威胁。近几十年来，人类的

18、工厂和汽车向大气中排放了数十亿吨的温室气体，全球气候已经表现出了变暖的趋势。许多人认为这是灾难即将来临的不祥征兆。如果我们不再抑制温室气体的肆意排放，那么那些海拔很低的国家可能被海水淹没，同时多雨和干旱地区的分布也会发生变化，飓风将愈加频繁，而厄尔尼诺”现象也会愈演愈烈。地球正在变暖现在令大多数人担忧的是在过去250年中人类已经人为地增加了大气中温室气体的浓度。我们的工厂、发电厂、汽车燃烧煤和汽油，排放出无穷尽的二氧化碳。我们任由垃圾在废渣填埋池里分解产生甲烷，还大量饲养胃里会产生甲烷气体的家畜，就这样我们人为制造了数百万吨的甲烷气体。我们几乎在所有的农田中都使用以氮为主要元素的化肥，导致超过

19、正常数量的氧化氮进入大气之中。一旦这些以碳为主要元素的温室气体进入大气层，它们就会存在几十年甚至更久。根据政府间气候变化问题专门研究小组的研究结果，自工业革命以来，空气中二氧化碳的含量增长了31%，甲烷气体的含量甚至增长了151%。从古代化石记录中得到的地质气候资料显示,这两种含量最多的温室气体（二氧化碳和甲烷）居过去42万年之首。许多科学家担心温室气体浓度日益增长会阻碍地球多余热量的散发。实际上，这些气体已经在阻碍地球大气中多余热量的散发，它们阻碍热量散发的原理就和汽车挡风玻璃阻碍太阳热量进入车厢是一样的。大量可获得的气候数据证明人们的担忧是很有道理的。从全球各地搜集的气温数据显示地球表面温

20、度，包括较低大气层和海洋表面温度，在过去几十年间剧烈上升。全球海平面测量数据也表明在上个世纪中，海平面上升了0.10.2米，也就是说海水温度每4000年上升大约1C。冰川研究数据也显示全球大陆冰川正在逐步消融。总而言之，以上这些数据都表明在过去一个世纪中，地球表面温度上升是近1000年里最快的。很自然地，许多科学家推测这种种气候变化很可能会导致天气越来越热，凉爽的日子越来越少。根据政府间气候变化问题专门研究小组的研究，地表夏季温度上升幅度将远大于海面温度的上升幅度。北半球中高纬度地例如美国大陆地区，加拿大和西伯利亚地区温度上升将最为剧烈。这些地区温度上升幅度将超过全球平均温度上升幅度的40%。就人类健康而言，那些受到最严