climatechange全球变暖.ppt

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1、ClimateChangeandSea-levelRise1ClimateChangeinthepastObservationMeasurementTemperatureChangeObservationMeasurementSincetheTAR,progressinunderstandinghowclimateischanginginspaceandintimehasbeengainedthroughimprovementsandextensionsofnumerousdatasetsandd

2、ataanalyses,broadergeographicalcoverage,betterunderstandingofuncertainties,andawidervarietyofmeasurements.TemperatureChangeThetotaltemperatureincreasefrom1850–1899to2001–2005is0.76[0.57to0.95]°C.Theupdated100-yearlineartrend(1906–2005)of0.74[0.56to0.9

3、2]°Cisthereforelargerthanthecorrespondingtrendfor1901-2000givenintheTARof0.6[0.4to0.8]°C.Thelinearwarmingtrendoverthelast50years(0.13[0.10to0.16]°Cperdecade)isnearlytwicethatforthelast100years.2HumanandNaturalDriversofClimateChangeMethodTheMainRadiati

4、veForcingMethodChangesintheatmosphericabundanceofgreenhousegasesandaerosols,insolarradiationandinlandsurfacepropertiesaltertheenergybalanceoftheclimatesystem.Thesechangesareexpressedintermsofradiativeforcing,whichisusedtocomparehowarangeofhumanandnatu

5、ralfactorsdrivewarmingorcoolinginfluencesonglobalclimate.TheMainRadiativeForcingGlobalatmosphericconcentrationsofcarbondioxide,methaneandnitrousoxidehaveincreasedmarkedlyasaresultofhumanactivitiessince1750andnowfarexceedpre-industrialvaluesdeterminedf

6、romicecoresspanningmanythousandsofyears.CarbonDioxideCarbondioxideisthemostimportantanthropogenicgreenhousegas.Theglobalatmosphericconcentrationofcarbondioxidehasincreasedfromapre-industrialvalueofabout280ppmto379ppmin2005.MethaneTheglobalatmosphericc

7、oncentrationofmethanehasincreasedfromapre-industrialvalueofabout715ppbto1732ppbintheearly1990s,andis1774ppbin2005.NitrousOxideTheglobalatmosphericnitrousoxideconcentrationincreasedfromapre-industrialvalueofabout270ppbto319ppbin2005.Anthropogeniccontri

8、butionsThecombinedradiativeforcingduetoincreasesincarbondioxide,methane,andnitrousoxideis+2.30[+2.07to+2.53]wm-2.SolarIrradianceChangesinsolarirradiancesince1750areestimatedtocausearadiativeforcingof+0.12[+0.06to+0.30]wm-2Theunderstandingofant