What is global warming, facts and information? - National ...

What is global warming, explained ... The planet is heating up—and fast. ... Glaciers are melting, sea levels are rising, cloud forests are dying, ... SkiptocontentRenewSubscribeMenuReferenceWhatisglobalwarming,explainedTheplanetisheatingup—andfast.2:49CausesandEffectsofClimateChangeGlaciersaremelting,sealevelsarerising,cloudforestsaredying,andwildlifeisscramblingtokeeppace.Ithasbecomeclearthathumanshavecausedmostofthepastcentury'swarmingbyreleasingheat-trappinggasesaswepowerourmodernlives.Calledgreenhousegases,theirlevelsarehighernowthanatanytimeinthelast800,000years.Weoftencalltheresultglobalwarming,butitiscausingasetofchangestotheEarth'sclimate,orlong-termweatherpatterns,thatvariesfromplacetoplace.Whilemanypeoplethinkofglobalwarmingandclimatechangeassynonyms,scientistsuse“climatechange”whendescribingthecomplexshiftsnowaffectingourplanet’sweatherandclimatesystems—inpartbecausesomeareasactuallygetcoolerintheshortterm.Climatechangeencompassesnotonlyrisingaveragetemperaturesbutalsoextremeweatherevents,shiftingwildlifepopulationsandhabitats,risingseas,andarangeofotherimpacts.Allofthosechangesareemergingashumanscontinuetoaddheat-trappinggreenhousegasestotheatmosphere,changingtherhythmsofclimatethatalllivingthingshavecometorelyon.Whatwillwedo—whatcanwedo—toslowthishuman-causedwarming?Howwillwecopewiththechangeswe'vealreadysetintomotion?Whilewestruggletofigureitallout,thefateoftheEarthasweknowit—coasts,forests,farms,andsnow-cappedmountains—hangsinthebalance.Pleaseberespectfulofcopyright.Unauthorizeduseisprohibited.Pleaseberespectfulofcopyright.Unauthorizeduseisprohibited.Pleaseberespectfulofcopyright.Unauthorizeduseisprohibited.Pleaseberespectfulofcopyright.Unauthorizeduseisprohibited.Pleaseberespectfulofcopyright.Unauthorizeduseisprohibited.Pleaseberespectfulofcopyright.Unauthorizeduseisprohibited.Pleaseberespectfulofcopyright.Unauthorizeduseisprohibited.Pleaseberespectfulofcopyright.Unauthorizeduseisprohibited.Pleaseberespectfulofcopyright.Unauthorizeduseisprohibited.Pleaseberespectfulofcopyright.Unauthorizeduseisprohibited.Pleaseberespectfulofcopyright.Unauthorizeduseisprohibited.1/111/11

AnicebergmeltsinthewatersoffAntarctica.Climatechangehasacceleratedtherateoficelossacrossthecontinent.

AnicebergmeltsinthewatersoffAntarctica.Climatechangehasacceleratedtherateoficelossacrossthecontinent. PhotographbyPaulNicklen,NatGeoImageCollectionUnderstandingthegreenhouseeffectThe"greenhouseeffect"isthewarmingthathappenswhencertaingasesinEarth'satmospheretrapheat.Thesegasesletinlightbutkeepheatfromescaping,liketheglasswallsofagreenhouse,hencethename.SunlightshinesontotheEarth'ssurface,wheretheenergyisabsorbedandthenradiatebackintotheatmosphereasheat.Intheatmosphere,greenhousegasmoleculestrapsomeoftheheat,andtherestescapesintospace.Themoregreenhousegasesconcentrateintheatmosphere,themoreheatgetslockedupinthemolecules.Scientistshaveknownaboutthegreenhouseeffectsince1824,whenJosephFouriercalculatedthattheEarthwouldbemuchcolderifithadnoatmosphere.ThisnaturalgreenhouseeffectiswhatkeepstheEarth'sclimatelivable.Withoutit,theEarth'ssurfacewouldbeanaverageofabout60degreesFahrenheit(33degreesCelsius)cooler.ApolarbearstandssentinelonRudolfIslandinRussia’sFranzJosefLandarchipelago,wheretheperennialiceismelting.PhotographbyCoryRichardsPleaseberespectfulofcopyright.Unauthorizeduseisprohibited.In1895,theSwedishchemistSvanteArrheniusdiscoveredthathumanscouldenhancethegreenhouseeffectbymakingcarbondioxide,agreenhousegas.Hekickedoff100yearsofclimateresearchthathasgivenusasophisticatedunderstandingofglobalwarming.LevelsofgreenhousegaseshavegoneupanddownovertheEarth'shistory,buttheyhadbeenfairlyconstantforthepastfewthousandyears.Globalaveragetemperatureshadalsostayedfairlyconstantoverthattime—untilthepast150years.Throughtheburningoffossilfuelsandotheractivitiesthathaveemittedlargeamountsofgreenhousegases,particularlyoverthepastfewdecades,humansarenowenhancingthegreenhouseeffectandwarmingEarthsignificantly,andinwaysthatpromisemanyeffects,scientistswarn.Aren'ttemperaturechangesnatural?Humanactivityisn'ttheonlyfactorthataffectsEarth'sclimate.Volcaniceruptionsandvariationsinsolarradiationfromsunspots,solarwind,andtheEarth'spositionrelativetothesunalsoplayarole.Sodolarge-scaleweatherpatternssuchasElNiño.ButclimatemodelsthatscientistsusetomonitorEarth’stemperaturestakethosefactorsintoaccount.Changesinsolarradiationlevelsaswellasminuteparticlessuspendedintheatmospherefromvolcaniceruptions,forexample,havecontributedonlyabouttwopercenttotherecentwarmingeffect.Thebalancecomesfromgreenhousegasesandotherhuman-causedfactors,suchaslandusechange.Theshorttimescaleofthisrecentwarmingissingularaswell.Volcaniceruptions,forexample,emitparticlesthattemporarilycooltheEarth'ssurface.Buttheireffectlastsjustafewyears.EventslikeElNiñoalsoworkonfairlyshortandpredictablecycles.Ontheotherhand,thetypesofglobaltemperaturefluctuationsthathavecontributedtoiceagesoccuronacycleofhundredsofthousandsofyears.Forthousandsofyearsnow,emissionsofgreenhousegasestotheatmospherehavebeenbalancedoutbygreenhousegasesthatarenaturallyabsorbed.Asaresult,greenhousegasconcentrationsandtemperatureshavebeenfairlystable,whichhasallowedhumancivilizationtoflourishwithinaconsistentclimate.Greenlandiscoveredwithavastamountofice—buttheiceismeltingfourtimesfasterthanthought,suggestingthatGreenlandmaybeapproachingadangeroustippingpoint,withimplicationsforglobalsea-levelrise.PhotographbyMichaelMelford,NatGeoImageCollectionPleaseberespectfulofcopyright.Unauthorizeduseisprohibited.Now,humanshaveincreasedtheamountofcarbondioxideintheatmospherebymorethanathirdsincetheIndustrialRevolution.Changesthathavehistoricallytakenthousandsofyearsarenowhappeningoverthecourseofdecades.Whydoesthismatter?Therapidriseingreenhousegasesisaproblembecauseit’schangingtheclimatefasterthansomelivingthingscanadaptto.Also,anewandmoreunpredictableclimateposesuniquechallengestoalllife.Historically,Earth'sclimatehasregularlyshiftedbetweentemperatureslikethoseweseetodayandtemperaturescoldenoughtocovermuchofNorthAmericaandEuropewithice.Thedifferencebetweenaverageglobaltemperaturestodayandduringthoseiceagesisonlyabout9degreesFahrenheit(5degreesCelsius),andtheswingshavetendedtohappenslowly,overhundredsofthousandsofyears.Butwithconcentrationsofgreenhousegasesrising,Earth'sremainingicesheetssuchasGreenlandandAntarcticaarestartingtomelttoo.Thatextrawatercouldraisesealevelssignificantly,andquickly.By2050,sealevelsarepredictedtorisebetweenoneand2.3feetasglaciersmelt.Asthemercuryrises,theclimatecanchangeinunexpectedways.Inadditiontosealevelsrising,weathercanbecomemoreextreme.Thismeansmoreintensemajorstorms,morerainfollowedbylongeranddrierdroughts—achallengeforgrowingcrops—changesintherangesinwhichplantsandanimalscanlive,andlossofwatersuppliesthathavehistoricallycomefromglaciers.ShareTweetEmailReadThisNextMagazineWelcometoEarthTrackingthegreatSerengetiwildebeestmigrationAmappingprojectletsyoufollowwildebeestsfittedwithGPScollarsastheysearchforfoodandwaterinoneofthelastlarge-mammalmigrationsonEarth.HowBerlin’sinfamousclubsceneisweatheringthepandemicHistory&CultureCoronavirusCoverageHowBerlin’sinfamousclubsceneisweatheringthepandemicNearlytwoyearsintoCOVID-19,thecity’srecentlyreopenednightspotstrytodancetheirwaytoahealthyClubKultur.Whyyoushouldn’tpanicovertheOmicronvariantScienceCoronavirusCoverageWhyyoushouldn’tpanicovertheOmicro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