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IsWeatherGettingWorse?WeatherseemsgettingworseandwildersinceMotherNatureisfullofsurprisesthesedays.Globalwarming,aheatedtopicoftoday,isoftentakenforgrantedtoberesponsiblefortheharshweather.However,scientists,likeKevinE.Trenberth,arecautiousinmakingtheirjudgment.PleasereadthefollowingarticleandfindoutwhatroleElNiňoandLaNiňaplay.天气正越变越糟？因为“这些日子大自然母亲充满着意想不到的事情”，看起来天气在越变越糟，越来越狂野。全球变暖是现在的热门话题，常常理所当然地被看成恶劣气候的罪魁祸首。但是，凯文?E?川伯斯这样的科学家在下定论时态度谨慎。请阅读以下文章，看一看厄尔尼诺和拉尼娜现象所起的作用。Asyoureadthis,flipyoureyesovertothewindow.Theskyisclear,thewindlight,andthesunbrilliant.Ormaybenot－MotherNatureisfullofsurprisesthesedays.Thecalendarsaysit'sspring,buttherecouldjustaseasilybeawinterblizzard,asummerswelter,oranautumncoldsnapontheothersideofthatglasspane.Almostinaninstant,itseems,theweathershiftsfromoneseasontoanother.Andwhereveritswings,itseemsincreasinglylikelytobeextreme.当你阅读本文时，请把目光轻快地投向窗外。天空澄净，微风轻拂，日光明媚。也许并不是这样——这些日子，大自然母亲充满着意想不到的事情。日历上说现在是春天，但窗外完全可能是一场冬季的暴风雪，一阵夏日的酷暑或一股秋天的寒流。几乎是在一瞬之间，气候就好象从一个季节转到了另一个季节。而且不管天气转向何方，它看起来变得越来越极端。ConsiderwhatMotherNatureslungourwaylastyearinMay,typicallythesecondworstmonthfortornadoes.Inlessthan24hours,morethan70hellholesofwindrampagedthroughOklahomaandKansas,killing49andcausingmorethan$1billionindamages.InJune,itwasheat,astheNortheastbeganroastingthroughweeksoftheworstdroughtsincethe1960s;256peopledied.ThisyearinJanuary,blizzardspoundedtheU.S.fromKansastotheAtlanticOcean.InApril,25inchesofsnowfellonpartsofNewEngland.想想看去年五月大自然母亲都给我们带来了些什么，那是第二个遭受龙卷风袭击最严重的月份。在不到二十四小时之内，七十多个“地狱”风暴在俄克拉何马和堪萨斯州横行肆虐，造成49人死亡以及十多亿美元的损失。六月，天气酷热，东北部连续几周在热浪下炙烤，遭受了自六十年代以来最严重的旱情，256人丧生。今年一月，暴风雪横扫美国，从堪萨斯州直至大西洋沿岸。四月，新英格兰部分地区下的雪厚达二十五英吋。Whyhasourweathergonewild?It'sthequestioneveryone'sasking,butaverytoughonetoanswer.Althoughmanyscientistsstillaren'tconvincedthatithasgonewild,somehavebegunsaying－cautiously,hesitantly－thatextremeweathereventsareoccurringwithmorefrequencythanatanytimeinthiscentury,eventsconsistentwiththeprofileofawarmingworld.Globalwarmingisreal,saysKevinE.Trenberth,headoftheClimateAnalysisSectionoftheCenterforAtmosphericResearchinBoulder,Colorado.Themeantemperaturesaregoingup.Thekeyquestionis:Whatwillitdolocally?Ithinkwe'regoingtostartfeelingitseffectsinthechangesonextremes.为什么我们的天气变得如此狂野？这是每个人都在问的问题，但是很难回答。虽然许多科学家仍然不相信天气已经失控，但有些人——虽然态度谨慎，仍存疑虑——已经开始说，与本世纪任何时段相比，极端性天气出现的频率愈加频繁，这与全球变暖的量变曲线是吻合的。凯文?E?川伯斯是设在科罗拉多州博耳德市的大气研究中心气候分析部的主任，他说：“全球变暖是事实。”“平均气温在上升。但关键问题是，它会给具体地区带来什么？我认为我们已开始感受到它的影响，天气的变化趋于极端。”Thatdoesn'tmeanyoucanindictweirdweatherinyourneckofthewoodsasproof.MotherNatureknowshowtohidehertracks.Shehurlsatorrentialdownpourtodayandadroughttomorrowfollowedbygentlerainthenextweek.Tounderstandapatterninnaturalvariability,youcan'tlookintothesky;youhavegottostudydata.Andforahostofreasons,thatisn'teasy.这并不意味着你可以用某一有限区域的怪异天气作为控诉的证据。大自然母亲知道该如何隐藏她的行踪。她今天猛地来一场倾盆大雨，明天是干旱，紧接着是一周柔柔细雨。你不能靠察看天象来了解自然变化的模式，你必须得研究数据。但由于种种原因，这并不容易。Buttallyingupthedamageis.Inthelast20years,thiscountryhasbeenwhackedby$I70billionworthofweather-relateddisasters－hurricanes,droughts,floods,andtornadoes.Thirty-eightsevereweathereventsoccurredinasingledecade,between1988and1999;seveneventsoccurredin1998alone－themostforanyyearonrecord.但是计算一下灾害损失却是容易的。过去的二十年里，我们这个国家与气候相关的灾难——飓风、干旱、洪水及龙卷风——造成了高达一千七百亿美元的损失。仅1988年至1999年这十年间就发生了38起严重的气候事件，仅1998年就有7起气候事件，这是有史以来受灾最多的一年。Globally,insurancecompaniesarecallingitacatastrophetrend.InareportissuedlastDecember,MunichRe,theworld'slargestreinsurer,orinsurerofinsurancecompanies,notedthatthenumberofnaturaldisastershasincreasedmorethanfourfoldsincethe1950s.Earthquakes,whicharenotweather-related,causednearlyhalfthedeathsinthosecatastrophes;storms,floods,andotherweatherwoeskilledtheotherhalf.In1999,thenumberofcatastrophesworldwidehit755,surpassingtherecordof702setonlytheyearbefore.从全球范围来看，保险公司把天气变暖称为“灾难趋势”。世界最大的再保险商，即为保险公司提供保险的墨尼黑再保险公司在去年十二月份发行的一份报告中指出，自20世纪50年代以来，自然灾害的数量已经增长了四倍有余。在这些灾难中，和气候无关的地震造成了近一半人的死亡；风暴、洪灾以及其它气候性灾难夺去了另一半人的生命。1999年，全世界的灾难数目达到755起，超过前一年才创下的702起的记录。Initsfive-pointlistofcausesforincreaseddamageclaims,MunichReblamedpopulationgrowthfirst,climatechangefifth.Criticsmaywellseizeuponthistodiminishclaimsthattheweatherisgettingworse,buttakentogether,it'samorefrighteningpicture.Thankstoswellingpopulationsincitiesandalongcoastalareas,moreofEarth'spassengersarelivinginthewrongplaceatthewrongtime.墨尼黑再保险公司在其列出的索赔要求日益增加的五点原因，认为人口增长首当其冲，天气变化则列在第五。一些批评家也许会紧抓住这一点来轻视天气正越变越糟的观点，但综合起来考虑，这是幅更可怕的画面。幸亏人口增长主要在城市和沿海地区，更多的“地球过客们”是在不适当的时间住在了不适当的地方。Still,thestatisticsmeteorologistshavecollectedonextremeweathereventsaren'tenoughtoprovethattheweatherisgettingworse.Bytheirverydefinition,extremeeventshappeninfrequently,andnoonehasbeencollectingscientificallysounddatalongenoughtoknowhowcommontheyare.Forexample,astormthathappensonceacenturymightrequiretwomillennia'sworthofstormdatatodrawconclusions.Totopitoff,thecomputermodelsscientistsusetostudyclimatecrunchnumbersonascaleofcenturiesatatime.Ideally,you'dlikedatasetsthatgobackseveralhundredyears,saysPhilipArkin,deputydirectoroftheInternationalResearchInstituteforClimatePredictionattheLamont-DohertyEarth