Scientistsfoundthatclimatechangebecamemoreandmoreunusualinrecentyears,notonlymayitcausemanyproblemssuchasglobalwarming,naturecalamities,andsoon,butalsoitcanaffectyourlife.Unusualclimatechangewouldletyoufeeluncomfortable,andaffectyourstudyandwork.Therefore,everyonehasresponsibilitytopayattentiontoit;furthermore,youneedtodoeverythinginyourpowertomaketheclimatebetterandbetter.However,atfirst,youneedtounderstandtwothings:themeaningofclimatechange,andtwoimportantfactorsofclimatechange:naturalcauses,andhumancauses.Thisessayisgoingtotalkaboutthesetwothings.

　　Atfirst,youmustunderstandthemeaningofclimatechange.Itmeansanylong-termsignificantchangeintheaverageweather,whichmayincludeaveragetemperature,precipitation,windpatternsandsoon.Forexample,Australiaisexperiencingrapidclimatechange.Sincethemiddleofthetwentiethcentury,Australiantemperatureshaverisenbyaboutaverageonetemperaturedegreewithanincreaseinthefrequencyofheatwavesandadecreaseinthenumbersoffrostsandcolddays.Rainfallpatternshavealsochanged,whichmeansthatthenorthwesthasseenanincreaseinrainfalloverthelastfiftyyearswhilemuchofeasternAustraliaandthefarsouthwesthaveexperiencedadecline.Fromthisexample,itindicatesclimatechangethatisoccurringtodayhasspedup,andaffectslong-termweather.TheEarth’sclimateislargelyaffectedbyhowmuchheatisstoredintheatmosphere.Furthermore,theclimatechangeiscausedbydynamicprocessonEarth,externalforcesincludingvariationsinsunlightintensity,andmorerecentlybyhumanactivities.

　　Themostimportantreasonofclimatechangeiscausedbyhumans,becausehumansproducealotofcarbondioxideintotheair.Thiscarbondioxideemitsfromfossilfuel,aerosols,cementmanufacture,landuse,animalagricultureanddeforestation.Forexample,treescantakeincarbondioxidetoproduceoxygenbyphotosynthesis.Ifpeoplecutmanytreesformakingfurniture,paper,orsellwoodtomakemoney,thereismuchmorecarbondioxideintheair.Beginningwiththeindustrialrevolutioninthenineteenthcenturyandacceleratingeversince,thehumanconsumptionoffossilfuelshasraisedcarbondioxidelevelsrapidly.Itmeansthatcarbondioxidelevelsaresubstantiallyhighernowthanbefore.Ontheotherhand,duringtheprocedureofmanufacturingcement,whichisusedinbuildings,significantlymorecarbondioxideisproduced.Whilepeopleimprovetheirlivingstandard,theycauseclimatechange.Whenpeopleburncoal,oil,andgasforourelectricity,carbondioxideisproduced.Whenpeopleburnfossilfueltomovevehicles,carbondioxideisalsoproduced.Thesesortsofexamplesindicatethathumansaretherealculprit.Theydonotconsidertheconsequence,whiletheyenjoyproducingeverythingtheywant.

　　Itisnotjustman-madepollutionoftheatmospherewhichcancauseclimatechange.ChangesintheamountofcarbondioxideintheairhaveoccurrednaturallyduringthehistoryoftheEarth,leadingtoclimatechanges.Whenavolcanoerupts,itreleaseshugeamountsofcarbondioxideandsulfurdioxideintotheatmosphere.However,volcanoeruptionscannoteffectclimatechange.Themainreasonisthatbeforethevolcanoerupts,itwouldreleasehugeamountofcarbondioxideandsulfurdioxideforaverylongtime.Thispollutioninjectedin