Istherelinkbetweenhumansandclimatechangeornot?Thisquestionwasfirststudiedintheearly1900s.Sincethenmanyscientistshavethoughtthatouractionsdomakeadifference.In1997theKyotoProtocolexplainedourroleintheEarth’schangingatmosphereandsetinternationallimitsforgasemissions(排放)from2008to2012.Somecountrieshavedecidedtocontinuethesereductionsuntil2020.MorerecentlytheParisAgreementstuckbynearly200countriesalsoaimstolimitglobalwarming.Butjustnowhowmuchwarmeritwillgetdependsonhowdeeplycountriescutcarbonemissions.
3.5℃
Thisishowmuchtemperatureswouldriseby2100evenifnationsliveuptotheinitialParispromisestoreducecarbonemissions;thisrisecouldstillputcoastalcitiesunderwateranddriveoverhalfofallspeciestoextinction.
2℃
TomeetthisminimumgoaltheAgreementrequirescountriestotightenemissionstargetseveryfiveyears.Eventhisincreasecouldsinksomeislandsworsedrought(干旱)anddriveadeclineofuptoathirdinthenumberofspecies.
1.5℃
ThisisthemostambitiousgoalfortemperaturerisesetbytheParisAgreementafterapushbylow-lyingislandnationslikeKiribatiwhichsaylimitingtemperatureriseto1.5℃couldsavethemfromsinking.
0.8℃
Thisishowmuchtemperatureshaverisensincetheindustrialagebeganputtingus40%ofthewaytothe2℃point.
0℃
Thebaselinehereisaverageglobaltemperaturebeforethestartoftheindustrialage.
70.Itcanbeconcludedfromparagraph1that_______.
A.theproblemofglobalwarmingwillhavebeenquitesolvedby2020
B.gasemissionshavebeeneffectivelyreducedindevelopedcountries
C.theParisAgreementsismoreinfluentialthantheKyotoProtocol
D.humanshavemadecontinuouseffortstoslowdownglobalwarming
71.IfnationscouldonlykeeptheinitialpromisesoftheParisAgreementwhatwouldhappenbytheyear2100?
A.Thehumanpopulationwouldincreasebyonethird.
B.Littleover50%ofallspecieswouldstillexist.
C.Nationswouldnotneedtotightentheiremissionstargets.
D.TheAgreement’sminimumgoalwouldnotbereached.