第三课沙漠之舟

ShipsintheDesertALGoreIwasstandinginthesunonthehotsteeldeck甲板ofafishingshipcapableofprocessing加工能力afifty-toncatchonagoodday.Butitwasn'tagoodday.Wewereanchored[‘æŋkə]锚inwhatusedtobethemostproductivefishingsiteinallofcentralAsia,butasIlookedoutoverthebow船头,theprospects前景ofagoodcatchlookedbleak.Wherethereshouldhavebeengentleblue-greenwaveslappingagainstthesideoftheship,therewasnothingbuthotdrysand–asfarasIcouldseeinalldirections.Theothershipsofthefleetwerealsoatrestinthesand,scatteredinthedunes沙丘thatstretchedallthewaytothehorizon.TenyearsagotheAral咸海wasthefourth-largestinlandseaintheworld,comparabletothelargestofNorthAmerica'sGreatLakes.Nowitisdisappearingbecausethewaterthatusedtofeedithasbeendivertedinanill-consideredirrigationschemetogrowcottonIntheusert.Thenewshorelinewasalmostfortykilometersacrossthesandfromwherethefishingfleetwasnowpermanentlydocked.Meanwhile,inthenearbytownofMuynakthepeoplewerestillcanningfish–broughtnotfromtheAralSeabutshippedbyrailthroughSiberiafromthePacificOcean,morethanathousandmilesaway.我头顶烈日站在一艘渔船的滚烫的钢甲板上。这艘渔船在丰收季节一天所处理加工的鱼可达15吨。但现在可不是丰收季节。这艘渔船此时此刻停泊的地方虽说曾是整个中亚地区最大的渔业基地，但当我站在船头向远处眺望时，却看出渔业丰收的希望非常渺茫。极目四顾，原先那种湛蓝色海涛轻拍船舷的景象已不复存在，取而代之的是茫茫的一片干燥灼热的沙漠。渔船队的其他渔船也都搁浅在沙漠上，散见于陂陀起伏、绵延至天边的沙丘间。十年前，咸海还是世界上第四大内陆湖泊，可与北美大湖区五大湖中的最大湖泊相媲美。而今，由于兴建了一项考虑欠周的水利工程，原来注入此湖的水被引入沙漠灌溉棉田，咸海这座大湖的水面已渐渐变小，新形成的湖岸距离这些渔船永远停泊的位置差不多有40公里远。与此同时，这儿附近的莫里那克镇上人们仍在生产鱼罐头，但所用的鱼已不是咸海所产，而是从一千多英里以外的太平洋渔业基地穿越西伯利亚运到这儿来的。Mysearchfortheunderlyingcausesoftheenvironmentalcrisishasledmetotravelaroundtheworldtoexamineandstudymanyoftheseimagesofdestruction.Attheverybottomoftheearth,highintheTrans-AntarcticMountains,withthesunglaringatmidnightthroughaholeinthesky,Istoodintheunbelievablecoldnessandtalkedwithascientistinthelatetallof1988aboutthetunnelhewasdiggingthroughtime.Slippinghisparkabacktorevealabadlyburnedfacethatwascrackedandpeeling,hepointedtotheannuallayersoficeinacoresampledugfromtheglacieronwhichwewerestanding.Hemovedhisfingerbackintimetotheiceoftwodecadesago.Here'swheretheU.SCongresspassedtheCleanAirAct,”hesaid.Atthebottomoftheworld,twocontinentsawayfromWashington,D.C.,evenasmallreductioninonecountry'semissionshadchangedtheamountofpollutionfoundintheremotestendleastaccessibleplaceonearth.Butthemostsignificantchangethusfarintheearth'satmosphereistheonethatbeganwiththeindustrialrevolutionearlyinthelastcenturyandhaspickedupspeedeversince.Industrymeantcoal,andlateroil,andwebegantoburnlotsofit–bringingrisinglevelsofcarbondioxide(CO2),withitsabilitytotrapmoreheatintheatmosphereandslowlywarmtheearth.FewerthanahundredyardsfromtheSouthPole,upwindfromtheicerunwaywheretheskiplanelandsandkeepsitsenginesrunningtopreventthemetalpartsfromfreeze-lockingtogether,scientistsmonitortheairseveraltimeseverydaytochartthecourseofthatinexorablechange.Duringmyvisit,Iwatchedonescientistdrawtheresultsofthatday'smeasurements,pushingtheendofasteeplinestillhigheronthegraph.Hetoldmehoweasyitis–thereattheendoftheearth–toseethatthisenormouschangeintheglobalatmosphereisstillpickingupspeed.TwoandahalfyearslaterIsleptunderthemidnightsunattheotherendofourplanet,inasmalltentpitchedonatwelve-toot-thickslaboficefloatinginthefrigidArcticOcean.Afteraheartybreakfast,mycompanionsandItraveledbysnowmobilesafewmilesfarthernorthtoarendezvouspointwheretheicewasthinner–onlythreeandahalffeetthick–andanuclearsubmarinehoveredinthewaterbelow.Afteritcrashedthroughtheice,tookonitsnewpassengers,andresubmerged,Italkedwithscientistswhoweretryingtomeasuremoreaccuratelythethicknessofthepolaricecap,whichmanybelieveisthinningasare-suitofglobalwarming.IhadjustnegotiatedanagreementbetweenicescientistsandtheU.S.Navytosecurethere-leaseofpreviouslytopsecretdatafromsubmarinesonartracks,datathatcouldhelpthemlearnwhatishappeningtothenorthpolarcap.Now,Iwantedtoseethepoleit-self,andsomeeighthoursafterwemetthesubmarine,wewerecrashingthroughthatice,surfacing,andthenIwasstandinginaneerilybeautifulsnowcape,windsweptandsparklingwhite,withthehorizondefinedbylittlehummocks,orpressureridgesoficethatarepushedupliketinymountainrangeswhenseparatesheetscollide.Butheretoo,CD,levelsarerisingjustasrapidly,andultimatelytemperaturewillrisewiththem–indeed,globalwarmingisexpectedtopushtemperaturesupmuchmorerapidlyinthepolarregionsthanintherestoftheworld.Asthepolarairwarms,theiceherewillthin;andsincethepolarcapplayssuchacrucialroleintheworld'sweathersystem,theconsequencesofathinningcapcouldbedisastrous.Consideringsuchscenariosisnotapurelyspeculativeexercise.SixmonthsafterIreturnedfromtheNorthPole,ateamofscientistsreporteddramaticchangesinthepatternoficedistributionintheArctic,andasecondteamreportedastillcontroversialclaim(whichavarietyofdatanowsuggest)that,overall,thenorthpolarcaphasthinnedby2percentinjustthelastdecade.Moreover,scientistsestablishedseveralyearsagothatinmanylandareasnorthoftheArcticCircle,thespringsnowmeltnowcomesearliereveryyear,anddeepinthetundrabelow,thetemperatureeoftheearthissteadilyrising.Asithappens,someofthemostdisturbingimagesofenvironmentaldestructioncanbefoundexactlyhalfwaybetweentheNorthandSouthp