资源描述：
《environmental protection(环境保护演讲ppt)》由会员上传分享，免费在线阅读，更多相关内容在教育资源-天天文库。
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
