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1、TeamfromlandscapearchitectureclassXTeamMembers:EnvironmentalProtectionOurtopicWhatdoyouknowaboutgreenhouseeffect?Globalwarming?Risingsealevels?Theimpactontheearth?OutlineGreenhouseeffectGlobalwarmingRisingsealevelsGreenhouseeffectWhatisthegreenhouseeffect?Onasunnywinterday
2、,youparkyourcarinthesun,lockit,andgocruisethelocalshoppingmallforacoupleofhours.Whenyoucomebacklaterandgetintoyourcar,whatdoyounotice?Istheinteriorofthecarhotorcold?Howdoesthetemperatureinsideofyourcarcomparetothetemperatureoutside?Ifyouhaveeverbeeninsideofagreenhouse,espe
3、ciallywhenthesunisout,whathaveyouobserved?Itisdefinitelywarm,andusuallytheairismoist.Agreenhouseiscommonlywarmerthantheoutsideairbecauseagreenhousehastheabilitytotrapheatinsideofit.Thisphenomenoniscalledthegreenhouseeffect.GreenhouseeffectTheheatcausedbyinfraredradiationis
4、absorbedby"greenhousegases"suchaswatervapor,carbondioxide,ozoneandmethane,whichslowsitsescapefromtheatmosphere.Althoughgreenhousegasesmakeuponlyabout1percentoftheEarth'satmosphere,theyregulateourclimatebytrappingheatandholdingitinakindofwarm-airblanketthatsurroundstheplane
5、t.Lifeontheearthdependsonenergyfromthesun.About30percentofthesunlightthatbeamstowardEarthisdeflectedbytheouteratmosphereandscatteredbackintospace.Therestreachestheplanet'ssurfaceandisreflectedupwardagainasatypeofslow-movingenergycalledinfraredradiation.GreenhouseeffectTheg
6、reenhouseeffectisanaturallyoccurringprocessthataidsinheatingtheEarth'ssurfaceandatmosphere.Itresultsfromthefactthatcertainatmosphericgases,suchascarbondioxide,watervapor,andmethane,areabletochangetheenergybalanceoftheplanetbyabsorbinglongwaveradiationemittedfromtheEarth'ss
7、urface.WithoutthegreenhouseeffectlifeonthisplanetwouldprobablynotexistastheaveragetemperatureoftheEarthwouldbeachilly-18°Celsius,ratherthanthepresent15°CelsiusGreenhouseeffectHowDoHumansContributetotheGreenhouseEffect?Whilethegreenhouseeffectisanessentialenvironmentalprere
8、quisiteforlifeonEarth,therereallycanbetoomuchofagoodthing.Theproblemsbeginwhenhumanactivi