材料全屏

材料全屏

                                    Soot(烟灰)andSnow:aHotCombination

【*】NewresearchfromNASAscientistssuggestsemissions(释放)ofblacksootalterthewaysunlightr eflectsoffsnow.

Accordingtoacomputersimulation(模拟),blacksootmayberesponsiblefor25percentofobservedglobalwarmingover

thepastcentury.

【*】Sootinthehigherlatitudes(纬度)oftheEarth,whereiceismorecommon,absorbsmoreofthesunsenergyand
warmththananicy,whitebackground.Dark-coloredblackcarbon,orsoot,absorbssunlight,whilelightercoloredicereflectssunlight

【*】Sootinareaswithsnowandicemayplayanimportantr oleinclimatechange.Also,ifsnowandicecoveredareasbeginmelting,thewarmingeffectincreases,asthesootbecomesmoreconcentr atedonthesnowsurface.Thisprovidesapositivefeedback,asglaciersandicesheetsmelt,theytendtogetevendirtier,"saidDr.JamesHansen,aresearcheratNASA's

GoddardInstituteforSpaceStudies,NewYork.

【*】Hansenfoundsoot'seffectonsnowalbedo(反照率)(solarenergyreflectedbacktospace),whichmaybecontr ibuting

totr endstowardearlyspringsintheNorthernHemisphere,suchasthinningArcticseaice,meltingglaciersandpermafrost(永冻层).Sootalsoisbelievedtoplayaroleinchangesintheatmosphereabovetheoceansandland.

【*】"Blackcarbonreducestheamountofenergyreflectedbysnowbackintospace,thusheatingthesnowsurfacemore
thaniftherewerenoblackcarbon,"Hansensaid.Soot'sincreasedabsorptionofsolarenergyisespeciallyeffectivein
warmingtheworld’sclimate."Thisforcingisunusuallyeffective,causingtwiceasmuchglobalwarmingasacarbon-dioxide(二氧化碳)forcingofthesamemagnitude(量,大小),”Hansennoted.【*】Hansencautioned,althoughtheroleofsootinalteringglobalclimateissubstantial,itd oesnotalterthefactthatgreenhousegasesaretheprimarycauseofclimatewarmingduringthepastcentury.Suchgasesareexpectedtobethelargestclimateforcingfortherestofthiscentury.【*】TheresearchersfoundthatobservedwarmingintheNorthernHemispherewaslargeinthewinterandspringat
middleandhighlatitudes.Theseobservationswereconsistentwiththeresearchers'elimatemodelsimulations,which
showedsomeofthelargestwarmingeffectsoccurredwhentherewereheavysnowcoverandsufficientsunlight.1

【单选】

Paragraph①_____

A

Soot'sRoleinClimateChangesAboveOceansandLand

B

ObservationsofWarmingintheNorthernHemisphere

C

ExplanationofIncreasedWarmingEffectCausedbySoot

D

BlackSootinSnowandIcyAreasLeadingtoClimateChange

E

BlackSootContr ibutingtoGlobalWarming

F

GreenhouseGasesastheMainFactorofGlobalWarming

答案及解析：段落大意概括类的题,一般需要寻找段落的关键句子或中心句以及关键词。以下同此。从第一段的最后半句可以看出,黑烟灰也加剧了全球气候变暖,应该负25%左右的责任。