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.