ScientistshavelongunderstoodthekeyrolethatoceansplayinregulatingtheEarth’sclimate.Oceanscover70percentoftheglobeandstoreathousandtimesmoreheatthantheatmospheredoes.What’sneweristheunderstandingofhow

　　ScientistshavelongunderstoodthekeyrolethatoceansplayinregulatingtheEarth’sclimate.Oceanscover70percentoftheglobeandstoreathousandtimesmoreheatthantheatmospheredoes.What’sneweristheunderstandingofhowthiskeycomponentofourclimatesystemrespondstoglobalwarming.

　　Abrakeonglobalwarming—fornow

　　Oneofoceans’mostimportantclimatefunctionsisabsorbingheatandcarbondioxide(CO2)oneofthegasesthatcauseglobalwarming.Actingasaheatsponge(海绵)oceanshaveabsorbedhugeamountsofheatandCO2inthelastfortyyears.

　　Fujitaexplainsthat"oceansaresavingusfromfasterclimatechange—theyareabigflywheelthatdelaysrapidoverheatingoftheEarthputtingabrakeontheclimatesystem."

　　"That’sthegoodnews"headds."Thebadnewsisthatoceansonlyslowtheatmosphericwarming.Onceoceanscometobalancewithagreenhousegaswarmedearththeextremeheatwillremainintheatmosphereandthingswillgetmuchhotter."Butwhereandhowoceansreleasethisaccumulated(积累的)heatisuncertain.Andasoceansstoreheatfragileunderwaterecosystemsarestruggling.

　　ThemostrecentscientificreportfromtheIntergovernmentalPanelonClimateChange(IPCC)alsonoteswithconcernthatoceansareacidifyingbecauseofincreasedabsorptionofatmosphericCO2andthuscausingathreatforshell-formingspecies.Sharpincreasesincarbondioxidelevelswillcausefurtheracidificationofoceans.

　　Currentsdistributingheat

　　Anotherimportantroleoceansplayisthatofdistributor.Oceansdeliverheatandlife-sustainingnutrientsaroundtheglobe.Justasbloodvesselsbringoxygenandnutrientstocellsinthehumanbodyoceans’currentscarryoxygennutrientsandheatthroughouttheEarth.Oceansdistribute25percentto50percentoftheenergytheplanetreceivesfromthesun.ForexampletheGulfStreamcarriesheatacrosstheAtlantic.ThiswarmcurrentgivesnorthwesternEuropeamilderclimatethanitwouldnormallyhavesofarnorth.Achangetooceans’circulation(循环)patternscouldthrowEuropeintoacolderperiodevenastherestofworldexperienceswarmertemperatures.

　　1.Wecaninferfromthepassagethat.

　　A.oceanscauseglobalwarming

　　B.oceansstop