SUBSCRIBE
Famine,economiccollapse,asunthatcooksus:Whatclimatechangecouldwreak—soonerthanyouthink.
ByDavidWallace-Wells
InthejunglesofCostaRica,wherehumidityroutinelytops90percent,simplymovingaroundoutsidewhenit’sover105degreesFahrenheitwouldbelethal.Andtheeffectwouldbefast:Withinafewhours,ahumanbodywouldbecookedtodeathfrom
bothinsideandout.
FossilsbyHeartlessMachine
Share
Tweet
Share
PinIt
Email
Comment
Print
July9,20179:00pm
I.‘Doomsday’
Peeringbeyondscientificreticence.
Itis,Ipromise,worsethanyouthink.Ifyouranxietyaboutglobalwarmingisdominatedbyfearsofsea-levelrise,youarebarelyscratchingthesurfaceofwhatterrorsarepossible,evenwithinthelifetime
ofateenagertoday.Andyettheswellingseas—andthecitiestheywilldrown—havesodominatedthepictureofglobalwarming,andsooverwhelmedourcapacityforclimatepanic,thattheyhave
occludedourperceptionofotherthreats,manymuchcloserathand.Risingoceansarebad,infactverybad;butfleeingthecoastlinewillnotbeenough.
Indeed,absentasignificantadjustmenttohowbillionsofhumansconducttheirlives,partsoftheEarthwilllikelybecomeclosetouninhabitable,andotherpartshorrificallyinhospitable,assoonastheend
ofthiscentury.
Evenwhenwetrainoureyesonclimatechange,weareunabletocomprehenditsscope.Thispastwinter,astringofdays60and70degreeswarmerthannormalbakedtheNorthPole,meltingthe
permafrostthatencasedNorway’sSvalbardseedvault—aglobalfoodbanknicknamed“Doomsday,”designedtoensurethatouragriculturesurvivesanycatastrophe,andwhichappearedtohavebeen
floodedbyclimatechangelessthantenyearsafterbeingbuilt.
TheDoomsdayvaultisfine,fornow:Thestructurehasbeensecuredandtheseedsaresafe.Buttreatingtheepisodeasaparableofimpendingfloodingmissedthemoreimportantnews.Untilrecently,
permafrostwasnotamajorconcernofclimatescientists,because,asthenamesuggests,itwassoilthatstayedpermanentlyfrozen.ButArcticpermafrostcontains1.8trilliontonsofcarbon,morethan
twiceasmuchasiscurrentlysuspendedintheEarth’satmosphere.Whenitthawsandisreleased,thatcarbonmayevaporateasmethane,whichis34timesaspowerfulagreenhouse-gaswarming
blanketascarbondioxidewhenjudgedonthetimescaleofacentury;whenjudgedonthetimescaleoftwodecades,itis86timesaspowerful.Inotherwords,wehave,trappedinArcticpermafrost,twice
asmuchcarbonasiscurrentlywreckingtheatmosphereoftheplanet,allofitscheduledtobereleasedatadatethatkeepsgettingmovedup,partiallyintheformofagasthatmultipliesitswarmingpower
86timesover.
Maybeyouknowthatalready—therearealarmingstorieseveryday,likelastmonth’ssatellitedatashowingtheglobewarming,since1998,morethantwiceasfastasscientistshadthought.Orthenews
fromAntarcticathispastMay,whenacrackinaniceshelfgrew11milesinsixdays,thenkeptgoing;thebreaknowhasjustthreemilestogo—bythetimeyoureadthis,itmayalreadyhavemetthe
openwater,whereitwilldropintotheseaoneofthebiggesticebergsever,aprocessknownpoeticallyas“calving.”
Butnomatterhowwell-informedyouare,youaresurelynotalarmedenough.Overthepastdecades,ourculturehasgoneapocalypticwithzombiemoviesandMadMaxdystopias,perhapsthecollective
resultofdisplacedclimateanxiety,andyetwhenitcomestocontemplatingreal-worldwarmingdangers,wesufferfromanincrediblefailureofimagination.Thereasonsforthataremany:thetimid
languageofscientificprobabilities,whichtheclimatologistJamesHansenoncecalled“scientificreticence”inapaperchastisingscientistsforeditingtheirownobservationssoconscientiouslythatthey
failedtocommunicatehowdirethethreatreallywas;thefactthatthecountryisdominatedbyagroupoftechnocratswhobelieveanyproblemcanbesolvedandanopposingculturethatdoesn’tevensee
warmingasaproblemworthaddressing;thewaythatclimatedenialismhasmadescientistsevenmorecautiousinofferingspeculativewarnings;thesimplespeedofchangeand,also,itsslowness,such
thatweareonlyseeingeffectsnowofwarmingfromdecadespast;ouruncertaintyaboutuncertainty,whichtheclimatewriterNaomiOreskesinparticularhassuggestedstopsusfrompreparingasthough
anythingworsethanamedianoutcomewereevenpossible;thewayweassumeclimatechangewillhithardestelsewhere,noteverywhere;thesmallness(twodegrees)andlargeness(1.8trilliontons)
andabstractness(400partspermillion)ofthenumbers;thediscomfortofconsideringaproblemthatisverydifficult,ifnotimpossible,tosolve;thealtogetherincomprehensiblescaleofthatproblem,which
amountstotheprospectofourownannihilation;simplefear.Butaversionarisingfromfearisaformofdenial,too.
Inbetweenscientificreticenceandsciencefictionisscienceitself.Thisarticleistheresultofdozensofinterviewsandexchangeswithclimatologistsandresearchersinrelatedfieldsandreflectshundreds
ofscientificpapersonthesubjectofclimatechange.Whatfollowsisnotaseriesofpredictionsofwhatwillhappen—thatwillbedeterminedinlargepartbythemuch-less-certainscienceofhuman
response.Instead,itisaportraitofourbestunderstandingofwheretheplanetisheadingabsentaggressiveaction.Itisunlikelythatallofthesewarmingscenarioswillbefullyrealized,largelybecause
thedevastationalongthewaywillshakeourcomplacency.Butthosescenarios,andnotthepresentclimate,arethebaseline.Infact,theyareourschedule.
Thepresenttenseofclimatechange—thedestructionwe’vealreadybakedintoourfuture—ishorrifyingenough.MostpeopletalkasifMiamiandBangladeshstillhaveachanceofsurviving;mostofthe
scientistsIspokewithassumewe’lllosethemwithinthecentury,evenifwestopburningfossilfuelinthenextdecade.Twodegreesofwarmingusedtobeconsideredthethresholdofcatastrophe:tensof
millionsofclimaterefugeesunleasheduponanunpreparedworld.Nowtwodegreesisourgoal,pertheParisclimateaccords,andexpertsgiveusonlyslimoddsofhittingit.TheU.N.Intergovernmental
PanelonClimateChangeissuesserialreports,oftencalledthe“goldstandard”ofclimateresearch;themostrecentoneprojectsustohitfourdegreesofwarmingbythebeginningofthenextcentury,
shouldwestaythepresentcourse.Butthat’sjustamedianprojection.Theupperendoftheprobabilitycurverunsashighaseightdegrees—andtheauthorsstillhaven’tfiguredouthowtodealwiththat
permafrostmelt.TheIPCCreportsalsodon’tfullyaccountforthealbedoeffect(lessicemeanslessreflectedandmoreabsorbedsunlight,hencemorewarming);morecloudcover(whichtrapsheat);or
thediebackofforestsandotherflora(whichextractcarbonfromtheatmosphere).Eachofthesepromisestoacceleratewarming,andthegeologicalrecordshowsthattemperaturecanshiftasmuchas
tendegreesormoreinasingledecade.Thelasttimetheplanetwasevenfourdegreeswarmer,PeterBrannenpointsoutinTheEndsoftheWorld,hisnewhistoryoftheplanet’smajorextinctionevents,
theoceanswerehundredsoffeethigher.*
TheEarthhasexperiencedfivemassextinctionsbeforetheonewearelivingthroughnow,eachsocompleteaslate-wipingoftheevolutionaryrecorditfunctionedasaresettingoftheplanetaryclock,and
manyclimatescientistswilltellyoutheyarethebestanalogfortheecologicalfuturewearedivingheadlonginto.Unlessyouareateenager,youprobablyreadinyourhigh-schooltextbooksthatthese
extinctionsweretheresultofasteroids.Infact,allbuttheonethatkilledthedinosaurswerecausedbyclimatechangeproducedbygreenhousegas.Themostnotoriouswas252millionyearsago;it
beganwhencarbonwarmedtheplanetbyfivedegrees,acceleratedwhenthatwarmingtriggeredthereleaseofmethaneintheArctic,andendedwith97percentofalllifeonEarthdead.Wearecurrently
addingcarbontotheatmosphereataconsiderablyfasterrate;bymostestimates,atleasttentimesfaster.Therateisaccelerating.ThisiswhatStephenHawkinghadinmindwhenhesaid,thisspring,
thatthespeciesneedstocolonizeotherplanetsinthenextcenturytosurvive,andwhatdroveElonMusk,lastmonth,tounveilhisplanstobuildaMarshabitatin40to100years.Theseare
nonspecialists,ofcourse,andprobablyasinclinedtoirrationalpanicasyouorI.Butthemanysober-mindedscientistsIinterviewedoverthepastseveralmonths—themostcredentialedandtenuredin
thefield,fewoftheminclinedtoalarmismandmanyadviserstotheIPCCwhoneverthelesscriticizeitsconservatism—havequietlyreachedanapocalypticconclusion,too:Noplausibleprogramof
emissionsreductionsalonecanpreventclimatedisaster.
Overthepastfewdecades,theterm“Anthropocene”hasclimbedoutofacademicdiscourseandintothepopularimagination—anamegiventothegeologiceraweliveinnow,andawaytosignalthatit
isanewera,definedonthewallchartofdeephistorybyhumanintervention.Oneproblemwiththetermisthatitimpliesaconquestofnature(andevenechoesthebiblical“dominion”).Andhowever
sanguineyoumightbeaboutthepropositionthatwehavealreadyravagedthenaturalworld,whichwesurelyhave,itisanotherthingentirelytoconsiderthepossibilitythatwehaveonlyprovokedit,
engineeringfirstinignoranceandthenindenialaclimatesystemthatwillnowgotowarwithusformanycenturies,perhapsuntilitdestroysus.ThatiswhatWallaceSmithBroecker,theavuncular
oceanographerwhocoinedtheterm“globalwarming,”meanswhenhecallstheplanetan“angrybeast.”Youcouldalsogowith“warmachine.”Eachdaywearmitmore.
II.HeatDeath
ThebahrainingofNewYork.
InthesugarcaneregionofElSalvador,asmuchasone-fifthofthepopulationhaschronickidneydisease,thepresumedresultofdehydrationfromworking
thefieldstheywereabletocomfortablyharvestasrecentlyastwodecadesago. Photo:HeartlessMachine
Humans,likeallmammals,areheatengines;survivingmeanshavingtocontinuallycooloff,likepantingdogs.Forthat,thetemperatureneedstobelowenoughfortheairtoactasakindofrefrigerant,
drawingheatofftheskinsotheenginecankeeppumping.Atsevendegreesofwarming,thatwouldbecomeimpossibleforlargeportionsoftheplanet’sequatorialband,andespeciallythetropics,where
humidityaddstotheproblem;inthejunglesofCostaRica,forinstance,wherehumidityroutinelytops90percent,simplymovingaroundoutsidewhenit’sover105degreesFahrenheitwouldbelethal.And
theeffectwouldbefast:Withinafewhours,ahumanbodywouldbecookedtodeathfrombothinsideandout.
Climate-changeskepticspointoutthattheplanethaswarmedandcooledmanytimesbefore,buttheclimatewindowthathasallowedforhumanlifeisverynarrow,evenbythestandardsofplanetary
history.At11or12degreesofwarming,morethanhalftheworld’spopulation,asdistributedtoday,woulddieofdirectheat.Thingsalmostcertainlywon’tgetthathotthiscentury,thoughmodelsof
unabatedemissionsdobringusthatfareventually.Thiscentury,andespeciallyinthetropics,thepainpointswillpinchmuchmorequicklyeventhananincreaseofsevendegrees.Thekeyfactoris
somethingcalledwet-bulbtemperature,whichisatermofmeasurementashome-laboratory-kitasitsounds:theheatregisteredonathermometerwrappedinadampsockasit’sswungaroundintheair
(sincethemoistureevaporatesfromasockmorequicklyindryair,thissinglenumberreflectsbothheatandhumidity).Atpresent,mostregionsreachawet-bulbmaximumof26or27degreesCelsius;the
trueredlineforhabitabilityis35degrees.Whatiscalledheatstresscomesmuchsooner.
Actually,we’reabouttherealready.Since1980,theplanethasexperienceda50-foldincreaseinthenumberofplacesexperiencingdangerousorextremeheat;abiggerincreaseistocome.Thefive
warmestsummersinEuropesince1500havealloccurredsince2002,andsoon,theIPCCwarns,simplybeingoutdoorsthattimeofyearwillbeunhealthyformuchoftheglobe.EvenifwemeettheParis
goalsoftwodegreeswarming,citieslikeKarachiandKolkatawillbecomeclosetouninhabitable,annuallyencounteringdeadlyheatwaveslikethosethatcrippledthemin2015.Atfourdegrees,thedeadly
Europeanheatwaveof2003,whichkilledasmanyas2,000peopleaday,willbeanormalsummer.Atsix,accordingtoanassessmentfocusedonlyoneffectswithintheU.S.fromtheNationalOceanic
andAtmosphericAdministration,summerlaborofanykindwouldbecomeimpossibleinthelowerMississippiValley,andeverybodyinthecountryeastoftheRockieswouldbeundermoreheatstressthan
anyone,anywhere,intheworldtoday.AsJosephRommhasputitinhisauthoritativeprimerClimateChange:WhatEveryoneNeedstoKnow,heatstressinNewYorkCitywouldexceedthatofpresentdayBahrain,oneoftheplanet’shottestspots,andthetemperatureinBahrain“wouldinducehyperthermiainevensleepinghumans.”Thehigh-endIPCCestimate,remember,istwodegreeswarmerstill.
Bytheendofthecentury,theWorldBankhasestimated,thecoolestmonthsintropicalSouthAmerica,Africa,andthePacificarelikelytobewarmerthanthewarmestmonthsattheendofthe20th
century.Air-conditioningcanhelpbutwillultimatelyonlyaddtothecarbonproblem;plus,theclimate-controlledmallsoftheArabemiratesaside,itisnotremotelyplausibletowholesaleair-conditionallthe
hottestpartsoftheworld,manyofthemalsothepoorest.Andindeed,thecrisiswillbemostdramaticacrosstheMiddleEastandPersianGulf,wherein2015theheatindexregisteredtemperaturesas
highas163degreesFahrenheit.Assoonasseveraldecadesfromnow,thehajjwillbecomephysicallyimpossibleforthe2millionMuslimswhomakethepilgrimageeachyear.
Itisnotjustthehajj,anditisnotjustMecca;heatisalreadykillingus.InthesugarcaneregionofElSalvador,asmuchasone-fifthofthepopulationhaschronickidneydisease,includingoveraquarterof
themen,thepresumedresultofdehydrationfromworkingthefieldstheywereabletocomfortablyharvestasrecentlyastwodecadesago.Withdialysis,whichisexpensive,thosewithkidneyfailurecan
expecttolivefiveyears;withoutit,lifeexpectancyisintheweeks.Ofcourse,heatstresspromisestopummelusinplacesotherthanourkidneys,too.AsItypethatsentence,intheCaliforniadesertin
mid-June,itis121degreesoutsidemydoor.Itisnotarecordhigh.
III.TheEndofFood
Prayingforcornfieldsinthetundra.
Climatesdifferandplantsvary,butthebasicruleforstaplecerealcropsgrownatoptimaltemperatureisthatforeverydegreeofwarming,yieldsdeclineby10percent.Someestimatesrunashighas15
oreven17percent.Whichmeansthatiftheplanetisfivedegreeswarmerattheendofthecentury,wemayhaveasmanyas50percentmorepeopletofeedand50percentlessgraintogivethem.And
proteinsareworse:Ittakes16caloriesofgraintoproducejustasinglecalorieofhamburgermeat,butcheredfromacowthatspentitslifepollutingtheclimatewithmethanefarts.
Pollyannaishplantphysiologistswillpointoutthatthecereal-cropmathappliesonlytothoseregionsalreadyatpeakgrowingtemperature,andtheyareright—theoretically,awarmerclimatewillmakeit
easiertogrowcorninGreenland.ButasthepathbreakingworkbyRosamondNaylorandDavidBattistihasshown,thetropicsarealreadytoohottoefficientlygrowgrain,andthoseplaceswheregrainis
producedtodayarealreadyatoptimalgrowingtemperature—whichmeansevenasmallwarmingwillpushthemdowntheslopeofdecliningproductivity.Andyoucan’teasilymovecroplandsnorthafew
hundredmiles,becauseyieldsinplaceslikeremoteCanadaandRussiaarelimitedbythequalityofsoilthere;ittakesmanycenturiesfortheplanettoproduceoptimallyfertiledirt.
Droughtmightbeanevenbiggerproblemthanheat,withsomeoftheworld’smostarablelandturningquicklytodesert.Precipitationisnotoriouslyhardtomodel,yetpredictionsforlaterthiscenturyare
basicallyunanimous:unprecedenteddroughtsnearlyeverywherefoodistodayproduced.By2080,withoutdramaticreductionsinemissions,southernEuropewillbeinpermanentextremedrought,much
worsethantheAmericandustbowleverwas.ThesamewillbetrueinIraqandSyriaandmuchoftherestoftheMiddleEast;someofthemostdenselypopulatedpartsofAustralia,Africa,andSouth
America;andthebreadbasketregionsofChina.Noneoftheseplaces,whichtodaysupplymuchoftheworld’sfood,willbereliablesourcesofany.Asfortheoriginaldustbowl:Thedroughtsinthe
AmericanplainsandSouthwestwouldnotjustbeworsethaninthe1930s,a2015NASAstudypredicted,butworsethananydroughtsinathousandyears—andthatincludesthosethatstruckbetween
1100and1300,which“driedupalltheriversEastoftheSierraNevadamountains”andmayhavebeenresponsibleforthedeathoftheAnasazicivilization.
Remember,wedonotliveinaworldwithouthungerasitis.Farfromit:Mostestimatesputthenumberofundernourishedat800millionglobally.Incaseyouhaven’theard,thisspringhasalreadybrought
anunprecedentedquadruplefaminetoAfricaandtheMiddleEast;theU.N.haswarnedthatseparatestarvationeventsinSomalia,SouthSudan,Nigeria,andYemencouldkill20millionthisyearalone.
IV.ClimatePlagues
Whathappenswhenthebubonicicemelts?
Rock,intherightspot,isarecordofplanetaryhistory,erasaslongasmillionsofyearsflattenedbytheforcesofgeologicaltimeintostratawithamplitudesofjustinches,orjustaninch,orevenless.Ice
worksthatway,too,asaclimateledger,butitisalsofrozenhistory,someofwhichcanbereanimatedwhenunfrozen.Therearenow,trappedinArcticice,diseasesthathavenotcirculatedintheairfor
millionsofyears—insomecases,sincebeforehumanswerearoundtoencounterthem.Whichmeansourimmunesystemswouldhavenoideahowtofightbackwhenthoseprehistoricplaguesemerge
fromtheice.
TheArcticalsostoresterrifyingbugsfrommorerecenttimes.InAlaska,already,researchershavediscoveredremnantsofthe1918fluthatinfectedasmanyas500millionandkilledasmanyas100
million—about5percentoftheworld’spopulationandalmostsixtimesasmanyashaddiedintheworldwarforwhichthepandemicservedasakindofgruesomecapstone.AstheBBCreportedinMay,
scientistssuspectsmallpoxandthebubonicplaguearetrappedinSiberianice,too—anabridgedhistoryofdevastatinghumansickness,leftoutlikeeggsaladintheArcticsun.
Expertscautionthatmanyoftheseorganismswon’tactuallysurvivethethawandpointtothefastidiouslabconditionsunderwhichtheyhavealreadyreanimatedseveralofthem—the32,000-year-old
“extremophile”bacteriarevivedin2005,an8million-year-oldbugbroughtbacktolifein2007,the3.5million–year–oldoneaRussianscientistself-injectedjustoutofcuriosity—tosuggestthatthoseare
necessaryconditionsforthereturnofsuchancientplagues.Butalreadylastyear,aboywaskilledand20othersinfectedbyanthraxreleasedwhenretreatingpermafrostexposedthefrozencarcassofa
reindeerkilledbythebacteriaatleast75yearsearlier;2,000present-dayreindeerwereinfected,too,carryingandspreadingthediseasebeyondthetundra.
Whatconcernsepidemiologistsmorethanancientdiseasesareexistingscourgesrelocated,rewired,orevenre-evolvedbywarming.Thefirsteffectisgeographical.Beforetheearly-modernperiod,when
adventuringsailboatsacceleratedthemixingofpeoplesandtheirbugs,humanprovincialitywasaguardagainstpandemic.Today,evenwithglobalizationandtheenormousinterminglingofhuman
populations,ourecosystemsaremostlystable,andthisfunctionsasanotherlimit,butglobalwarmingwillscramblethoseecosystemsandhelpdiseasetrespassthoselimitsassurelyasCortésdid.You
don’tworrymuchaboutdengueormalariaifyouarelivinginMaineorFrance.Butasthetropicscreepnorthwardandmosquitoesmigratewiththem,youwill.Youdidn’tmuchworryaboutZikaacoupleof
yearsago,either.
Asithappens,Zikamayalsobeagoodmodelofthesecondworryingeffect—diseasemutation.Onereasonyouhadn’theardaboutZikauntilrecentlyisthatithadbeentrappedinUganda;anotheris
thatitdidnot,untilrecently,appeartocausebirthdefects.Scientistsstilldon’tentirelyunderstandwhathappened,orwhattheymissed.Buttherearethingswedoknowforsureabouthowclimateaffects
somediseases:Malaria,forinstance,thrivesinhotterregionsnotjustbecausethemosquitoesthatcarryitdo,too,butbecauseforeverydegreeincreaseintemperature,theparasitereproducestentimes
faster.WhichisonereasonthattheWorldBankestimatesthatby2050,5.2billionpeoplewillbereckoningwithit.
V.UnbreathableAir
Arollingdeathsmogthatsuffocatesmillions.
Bytheendofthecentury,thecoolestmonthsintropicalSouthAmerica,Africa,andthePacificarelikelytobewarmerthanthewarmestmonthsattheend
ofthe20thcentury. Photo:HeartlessMachine
Ourlungsneedoxygen,butthatisonlyafractionofwhatwebreathe.Thefractionofcarbondioxideisgrowing:Itjustcrossed400partspermillion,andhigh-endestimatesextrapolatingfromcurrent
trendssuggestitwillhit1,000ppmby2100.Atthatconcentration,comparedtotheairwebreathenow,humancognitiveabilitydeclinesby21percent.
Otherstuffinthehotterairisevenscarier,withsmallincreasesinpollutioncapableofshorteninglifespansbytenyears.Thewarmertheplanetgets,themoreozoneforms,andbymid-century,Americans
willlikelysuffera70percentincreaseinunhealthyozonesmog,theNationalCenterforAtmosphericResearchhasprojected.By2090,asmanyas2billionpeoplegloballywillbebreathingairabovethe
WHO“safe”level;onepaperlastmonthshowedthat,amongothereffects,apregnantmother’sexposuretoozoneraisesthechild’sriskofautism(asmuchastenfold,combinedwithotherenvironmental
factors).WhichdoesmakeyouthinkagainabouttheautismepidemicinWestHollywood.
Already,morethan10,000peopledieeachdayfromthesmallparticlesemittedfromfossil-fuelburning;eachyear,339,000peoplediefromwildfiresmoke,inpartbecauseclimatechangehasextended
forest-fireseason(intheU.S.,it’sincreasedby78dayssince1970).By2050,accordingtotheU.S.ForestService,wildfireswillbetwiceasdestructiveastheyaretoday;insomeplaces,theareaburned
couldgrowfivefold.Whatworriespeopleevenmoreistheeffectthatwouldhaveonemissions,especiallywhenthefiresravageforestsarisingoutofpeat.PeatlandfiresinIndonesiain1997,forinstance,
addedtotheglobalCO2releasebyupto40percent,andmoreburningonlymeansmorewarmingonlymeansmoreburning.ThereisalsotheterrifyingpossibilitythatrainforestsliketheAmazon,which
in2010suffereditssecond“hundred-yeardrought”inthespaceoffiveyears,coulddryoutenoughtobecomevulnerabletothesekindsofdevastating,rollingforestfires—whichwouldnotonlyexpel
enormousamountsofcarbonintotheatmospherebutalsoshrinkthesizeoftheforest.ThatisespeciallybadbecausetheAmazonaloneprovides20percentofouroxygen.
Thentherearethemorefamiliarformsofpollution.In2013,meltingArcticiceremodeledAsianweatherpatterns,deprivingindustrialChinaofthenaturalventilationsystemsithadcometodependon,
whichblanketedmuchofthecountry’snorthinanunbreathablesmog.Literallyunbreathable.AmetriccalledtheAirQualityIndexcategorizestherisksandtopsoutatthe301-to-500range,warningof
“seriousaggravationofheartorlungdiseaseandprematuremortalityinpersonswithcardiopulmonarydiseaseandtheelderly”and,forallothers,“seriousriskofrespiratoryeffects”;atthatlevel,
“everyoneshouldavoidalloutdoorexertion.”TheChinese“airpocalypse”of2013peakedatwhatwouldhavebeenanAirQualityIndexofover800.Thatyear,smogwasresponsibleforathirdofalldeaths
inthecountry.
VI.PerpetualWar
Theviolencebakedintoheat.
ClimatologistsareverycarefulwhentalkingaboutSyria.Theywantyoutoknowthatwhileclimatechangedidproduceadroughtthatcontributedtocivilwar,itisnotexactlyfairtosaythattheconflictisthe
resultofwarming;nextdoor,forinstance,Lebanonsufferedthesamecropfailures.ButresearcherslikeMarshallBurkeandSolomonHsianghavemanagedtoquantifysomeofthenon-obvious
relationshipsbetweentemperatureandviolence:Foreveryhalf-degreeofwarming,theysay,societieswillseebetweena10and20percentincreaseinthelikelihoodofarmedconflict.Inclimatescience,
nothingissimple,butthearithmeticisharrowing:Aplanetfivedegreeswarmerwouldhaveatleasthalfagainasmanywarsaswedotoday.Overall,socialconflictcouldmorethandoublethiscentury.
Thisisonereasonthat,asnearlyeveryclimatescientistIspoketopointedout,theU.S.militaryisobsessedwithclimatechange:ThedrowningofallAmericanNavybasesbysea-levelriseistrouble
enough,butbeingtheworld’spolicemanisquiteabitharderwhenthecrimeratedoubles.Ofcourse,it’snotjustSyriawhereclimatehascontributedtoconflict.Somespeculatethattheelevatedlevelof
strifeacrosstheMiddleEastoverthepastgenerationreflectsthepressuresofglobalwarming—ahypothesisallthemorecruelconsideringthatwarmingbeganacceleratingwhentheindustrializedworld
extractedandthenburnedtheregion’soil.
Whataccountsfortherelationshipbetweenclimateandconflict?Someofitcomesdowntoagricultureandeconomics;alothastodowithforcedmigration,alreadyatarecordhigh,withatleast65million
displacedpeoplewanderingtheplanetrightnow.Butthereisalsothesimplefactofindividualirritability.Heatincreasesmunicipalcrimerates,andswearingonsocialmedia,andthelikelihoodthata
major-leaguepitcher,comingtothemoundafterhisteammatehasbeenhitbyapitch,willhitanopposingbatterinretaliation.Andthearrivalofair-conditioninginthedevelopedworld,inthemiddleofthe
pastcentury,didlittletosolvetheproblemofthesummercrimewave.
VII.PermanentEconomicCollapse
Dismalcapitalisminahalf-poorerworld.
Themurmuringmantraofglobalneoliberalism,whichprevailedbetweentheendoftheColdWarandtheonsetoftheGreatRecession,isthateconomicgrowthwouldsaveusfromanythingand
everything.
Butintheaftermathofthe2008crash,agrowingnumberofhistoriansstudyingwhattheycall“fossilcapitalism”havebeguntosuggestthattheentirehistoryofswifteconomicgrowth,whichbegan
somewhatsuddenlyinthe18thcentury,isnottheresultofinnovationortradeorthedynamicsofglobalcapitalismbutsimplyourdiscoveryoffossilfuelsandalltheirrawpower—aonetimeinjectionof
new“value”intoasystemthathadpreviouslybeencharacterizedbyglobalsubsistenceliving.Beforefossilfuels,nobodylivedbetterthantheirparentsorgrandparentsorancestorsfrom500yearsbefore,
exceptintheimmediateaftermathofagreatplagueliketheBlackDeath,whichallowedtheluckysurvivorstogobbleuptheresourcesliberatedbymassgraves.Afterwe’veburnedallthefossilfuels,
thesescholarssuggest,perhapswewillreturntoa“steadystate”globaleconomy.Ofcourse,thatonetimeinjectionhasadevastatinglong-termcost:climatechange.
ThemostexcitingresearchontheeconomicsofwarminghasalsocomefromHsiangandhiscolleagues,whoarenothistoriansoffossilcapitalismbutwhooffersomeverybleakanalysisoftheirown:
EverydegreeCelsiusofwarmingcosts,onaverage,1.2percentofGDP(anenormousnumber,consideringwecountgrowthinthelowsingledigitsas“strong”).Thisisthesterlingworkinthefield,and
theirmedianprojectionisfora23percentlossinpercapitaearninggloballybytheendofthiscentury(resultingfromchangesinagriculture,crime,storms,energy,mortality,andlabor).
Tracingtheshapeoftheprobabilitycurveisevenscarier:Thereisa12percentchancethatclimatechangewillreduceglobaloutputbymorethan50percentby2100,theysay,anda51percentchance
thatitlowerspercapitaGDPby20percentormorebythen,unlessemissionsdecline.Bycomparison,theGreatRecessionloweredglobalGDPbyabout6percent,inaonetimeshock;Hsiangandhis
colleaguesestimateaone-in-eightchanceofanongoingandirreversibleeffectbytheendofthecenturythatiseighttimesworse.
Thescaleofthateconomicdevastationishardtocomprehend,butyoucanstartbyimaginingwhattheworldwouldlookliketodaywithaneconomyhalfasbig,whichwouldproduceonlyhalfasmuch
value,generatingonlyhalfasmuchtooffertheworkersoftheworld.Itmakesthegroundingofflightsoutofheat-strickenPhoenixlastmonthseemlikepatheticallysmalleconomicpotatoes.And,among
otherthings,itmakestheideaofpostponinggovernmentactiononreducingemissionsandrelyingsolelyongrowthandtechnologytosolvetheproblemanabsurdbusinesscalculation.
Everyround-tripticketonflightsfromNewYorktoLondon,keepinmind,coststheArcticthreemoresquaremetersofice.
VIII.PoisonedOceans
Sulfideburpsofftheskeletoncoast.
Thattheseawillbecomeakillerisagiven.Barringaradicalreductionofemissions,wewillseeatleastfourfeetofsea-levelriseandpossiblytenbytheendofthecentury.Athirdoftheworld’smajor
citiesareonthecoast,nottomentionitspowerplants,ports,navybases,farmlands,fisheries,riverdeltas,marshlands,andrice-paddyempires,andeventhoseabovetenfeetwillfloodmuchmoreeasily,
andmuchmoreregularly,ifthewatergetsthathigh.Atleast600millionpeoplelivewithintenmetersofsealeveltoday.
Butthedrowningofthosehomelandsisjustthestart.Atpresent,morethanathirdoftheworld’scarbonissuckedupbytheoceans—thankGod,orelsewe’dhavethatmuchmorewarmingalready.But
theresultiswhat’scalled“oceanacidification,”which,onitsown,mayaddahalfadegreetowarmingthiscentury.Itisalsoalreadyburningthroughtheplanet’swaterbasins—youmayrememberthese
astheplacewherelifearoseinthefirstplace.Youhaveprobablyheardof“coralbleaching”—thatis,coraldying—whichisverybadnews,becausereefssupportasmuchasaquarterofallmarinelife
andsupplyfoodforhalfabillionpeople.Oceanacidificationwillfryfishpopulationsdirectly,too,thoughscientistsaren’tyetsurehowtopredicttheeffectsonthestuffwehauloutoftheoceantoeat;they
doknowthatinacidwaters,oystersandmusselswillstruggletogrowtheirshells,andthatwhenthepHofhumanblooddropsasmuchastheoceans’pHhasoverthepastgeneration,itinducesseizures,
comas,andsuddendeath.
Thatisn’tallthatoceanacidificationcando.Carbonabsorptioncaninitiateafeedbackloopinwhichunderoxygenatedwatersbreeddifferentkindsofmicrobesthatturnthewaterstillmore“anoxic,”firstin
deepocean“deadzones,”thengraduallyuptowardthesurface.There,thesmallfishdieout,unabletobreathe,whichmeansoxygen-eatingbacteriathrive,andthefeedbackloopdoublesback.This
process,inwhichdeadzonesgrowlikecancers,chokingoffmarinelifeandwipingoutfisheries,isalreadyquiteadvancedinpartsoftheGulfofMexicoandjustoffNamibia,wherehydrogensulfideis
bubblingoutoftheseaalongathousand-milestretchoflandknownasthe“SkeletonCoast.”Thenameoriginallyreferredtothedetritusofthewhalingindustry,buttodayit’smoreaptthanever.Hydrogen
sulfideissotoxicthatevolutionhastrainedustorecognizethetiniest,safesttracesofit,whichiswhyournosesaresoexquisitelyskilledatregisteringflatulence.Hydrogensulfideisalsothethingthat
finallydidusinthattime97percentofalllifeonEarthdied,onceallthefeedbackloopshadbeentriggeredandthecirculatingjetstreamsofawarmedoceangroundtoahalt—it’stheplanet’spreferred
gasforanaturalholocaust.Gradually,theocean’sdeadzonesspread,killingoffmarinespeciesthathaddominatedtheoceansforhundredsofmillionsofyears,andthegastheinertwatersgaveoffinto
theatmospherepoisonedeverythingonland.Plants,too.Itwasmillionsofyearsbeforetheoceansrecovered.
IX.TheGreatFilter
Ourpresenteerinesscannotlast.
Sowhycan’tweseeit?Inhisrecentbook-lengthessayTheGreatDerangement,theIndiannovelistAmitavGhoshwonderswhyglobalwarmingandnaturaldisasterhaven’tbecomemajorsubjectsof
contemporaryfiction—whywedon’tseemabletoimagineclimatecatastrophe,andwhywehaven’tyethadaspateofnovelsinthegenrehebasicallyimaginesintohalf-existenceandnames“the
environmentaluncanny.”“Consider,forexample,thestoriesthatcongealaroundquestionslike,‘WherewereyouwhentheBerlinWallfell?’or‘Wherewereyouon9/11?’ ”hewrites.“Williteverbe
possibletoask,inthesamevein,‘Wherewereyouat400ppm?’or‘WherewereyouwhentheLarsenBiceshelfbrokeup?’ ”Hisanswer:Probablynot,becausethedilemmasanddramasofclimate
changearesimplyincompatiblewiththekindsofstorieswetellourselvesaboutourselves,especiallyinnovels,whichtendtoemphasizethejourneyofanindividualconscienceratherthanthepoisonous
miasmaofsocialfate.
Surelythisblindnesswillnotlast—theworldweareabouttoinhabitwillnotpermitit.Inasix-degree-warmerworld,theEarth’secosystemwillboilwithsomanynaturaldisastersthatwewilljuststart
callingthem“weather”:aconstantswarmofout-of-controltyphoonsandtornadoesandfloodsanddroughts,theplanetassaultedregularlywithclimateeventsthatnotsolongagodestroyedwhole
civilizations.Thestrongesthurricaneswillcomemoreoften,andwe’llhavetoinventnewcategorieswithwhichtodescribethem;tornadoeswillgrowlongerandwiderandstrikemuchmorefrequently,and
hailrockswillquadrupleinsize.Humansusedtowatchtheweathertoprophesythefuture;goingforward,wewillseeinitswraththevengeanceofthepast.Earlynaturaliststalkedoftenabout“deeptime”
—theperceptiontheyhad,contemplatingthegrandeurofthisvalleyorthatrockbasin,oftheprofoundslownessofnature.WhatliesinstoreforusismorelikewhattheVictoriananthropologistsidentified
as“dreamtime,”or“everywhen”:thesemi-mythicalexperience,describedbyAboriginalAustralians,ofencountering,inthepresentmoment,anout-of-timepast,whenancestors,heroes,anddemigods
crowdedanepicstage.Youcanfinditalreadywatchingfootageofanicebergcollapsingintothesea—afeelingofhistoryhappeningallatonce.
Itis.Manypeopleperceiveclimatechangeasasortofmoralandeconomicdebt,accumulatedsincethebeginningoftheIndustrialRevolutionandnowcomedueafterseveralcenturies—ahelpful
perspective,inaway,sinceitisthecarbon-burningprocessesthatbeganin18th-centuryEnglandthatlitthefuseofeverythingthatfollowed.Butmorethanhalfofthecarbonhumanityhasexhaledinto
theatmosphereinitsentirehistoryhasbeenemittedinjustthepastthreedecades;sincetheendofWorldWarII,thefigureis85percent.Whichmeansthat,inthelengthofasinglegeneration,global
warminghasbroughtustothebrinkofplanetarycatastrophe,andthatthestoryoftheindustrialworld’skamikazemissionisalsothestoryofasinglelifetime.Myfather’s,forinstance:bornin1938,among
hisfirstmemoriesthenewsofPearlHarborandthemythicAirForceofthepropagandafilmsthatfollowed,filmsthatdoubledasadvertisementsforimperial-Americanindustrialmight;andamonghislast
memoriesthecoverageofthedesperatesigningoftheParisclimateaccordsoncablenews,tenweeksbeforehediedoflungcancerlastJuly.Ormymother’s:bornin1945,toGermanJewsfleeingthe
smokestacksthroughwhichtheirrelativeswereincinerated,nowenjoyingher72ndyearinanAmericancommodityparadise,aparadisesupportedbythesupplychainsofanindustrializeddeveloping
world.Shehasbeensmokingfor57ofthoseyears,unfiltered.
Orthescientists’.Someofthemenwhofirstidentifiedachangingclimate(andgiventhegeneration,thosewhobecamefamousweremen)arestillalive;afewareevenstillworking.WallyBroeckeris84
yearsoldanddrivestoworkattheLamont-DohertyEarthObservatoryacrosstheHudsoneverydayfromtheUpperWestSide.Likemostofthosewhofirstraisedthealarm,hebelievesthatnoamountof
emissionsreductionalonecanmeaningfullyhelpavoiddisaster.Instead,heputshisfaithincarboncapture—untestedtechnologytoextractcarbondioxidefromtheatmosphere,whichBroecker
estimateswillcostatleastseveraltrilliondollars—andvariousformsof“geoengineering,”thecatchallnameforavarietyofmoon-shottechnologiesfar-fetchedenoughthatmanyclimatescientistsprefer
toregardthemasdreams,ornightmares,fromsciencefiction.Heisespeciallyfocusedonwhat’scalledtheaerosolapproach—dispersingsomuchsulfurdioxideintotheatmospherethatwhenit
convertstosulfuricacid,itwillcloudafifthofthehorizonandreflectback2percentofthesun’srays,buyingtheplanetatleastalittlewiggleroom,heat-wise.“Ofcourse,thatwouldmakeoursunsetsvery
red,wouldbleachthesky,wouldmakemoreacidrain,”hesays.“Butyouhavetolookatthemagnitudeoftheproblem.Yougottowatchthatyoudon’tsaythegiantproblemshouldn’tbesolvedbecause
thesolutioncausessomesmallerproblems.”Hewon’tbearoundtoseethat,hetoldme.“Butinyourlifetime…”
JimHansenisanothermemberofthisgodfathergeneration.Bornin1941,hebecameaclimatologistattheUniversityofIowa,developedthegroundbreaking“ZeroModel”forprojectingclimatechange,
andlaterbecametheheadofclimateresearchatNASA,onlytoleaveunderpressurewhen,whilestillafederalemployee,hefiledalawsuitagainstthefederalgovernmentcharginginactiononwarming
(alongthewayhegotarrestedafewtimesforprotesting,too).Thelawsuit,whichisbroughtbyacollectivecalledOurChildren’sTrustandisoftendescribedas“kidsversusclimatechange,”isbuiltonan
appealtotheequal-protectionclause,namely,thatinfailingtotakeactiononwarming,thegovernmentisviolatingitbyimposingmassivecostsonfuturegenerations;itisscheduledtobeheardthiswinter
inOregondistrictcourt.Hansenhasrecentlygivenuponsolvingtheclimateproblemwithacarbontax,whichhadbeenhispreferredapproach,andhassetaboutcalculatingthetotalcostofextracting
carbonfromtheatmosphereinstead.
HansenbeganhiscareerstudyingVenus,whichwasonceaveryEarth-likeplanetwithplentyoflife-supportingwaterbeforerunawayclimatechangerapidlytransformeditintoanaridanduninhabitable
sphereenvelopedinanunbreathablegas;heswitchedtostudyingourplanetby30,wonderingwhyheshouldbesquintingacrossthesolarsystemtoexplorerapidenvironmentalchangewhenhecould
seeitallaroundhimontheplanethewasstandingon.“Whenwewroteourfirstpaperonthis,in1981,”hetoldme,“Iremembersayingtooneofmyco-authors,‘Thisisgoingtobeveryinteresting.
Sometimeduringourcareers,we’regoingtoseethesethingsbeginningtohappen.’ ”
SeveralofthescientistsIspokewithproposedglobalwarmingasthesolutiontoFermi’sfamousparadox,whichasks,Iftheuniverseissobig,thenwhyhaven’tweencounteredanyotherintelligentlifein
it?Theanswer,theysuggested,isthatthenaturallifespanofacivilizationmaybeonlyseveralthousandyears,andthelifespanofanindustrialcivilizationperhapsonlyseveralhundred.Inauniversethat
ismanybillionsofyearsold,withstarsystemsseparatedasmuchbytimeasbyspace,civilizationsmightemergeanddevelopandburnthemselvesupsimplytoofasttoeverfindoneanother.Peter
Ward,acharismaticpaleontologistamongthoseresponsiblefordiscoveringthattheplanet’smassextinctionswerecausedbygreenhousegas,callsthisthe“GreatFilter”:“Civilizationsrise,butthere’san
environmentalfilterthatcausesthemtodieoffagainanddisappearfairlyquickly,”hetoldme.“IfyoulookatplanetEarth,thefilteringwe’vehadinthepasthasbeeninthesemassextinctions.”Themass
extinctionwearenowlivingthroughhasonlyjustbegun;somuchmoredyingiscoming.
Andyet,improbably,Wardisanoptimist.SoareBroeckerandHansenandmanyoftheotherscientistsIspoketo.Wehavenotdevelopedmuchofareligionofmeaningaroundclimatechangethatmight
comfortus,orgiveuspurpose,inthefaceofpossibleannihilation.Butclimatescientistshaveastrangekindoffaith:Wewillfindawaytoforestallradicalwarming,theysay,becausewemust.
Itisnoteasytoknowhowmuchtobereassuredbythatbleakcertainty,andhowmuchtowonderwhetheritisanotherformofdelusion;forglobalwarmingtoworkasparable,ofcourse,someoneneeds
tosurvivetotellthestory.ThescientistsknowthattoevenmeettheParisgoals,by2050,carbonemissionsfromenergyandindustry,whicharestillrising,willhavetofallbyhalfeachdecade;emissions
fromlanduse(deforestation,cowfarts,etc.)willhavetozeroout;andwewillneedtohaveinventedtechnologiestoextract,annually,twiceasmuchcarbonfromtheatmosphereastheentireplanet’s
plantsnowdo.Nevertheless,byandlarge,thescientistshaveanenormousconfidenceintheingenuityofhumans—aconfidenceperhapsbolsteredbytheirappreciationforclimatechange,whichis,
afterall,ahumaninvention,too.TheypointtotheApolloproject,theholeintheozonewepatchedinthe1980s,thepassingofthefearofmutuallyassureddestruction.Nowwe’vefoundawaytoengineer
ourowndoomsday,andsurelywewillfindawaytoengineerourwayoutofit,onewayoranother.Theplanetisnotusedtobeingprovokedlikethis,andclimatesystemsdesignedtogivefeedbackover
centuriesormillenniapreventus—eventhosewhomaybewatchingclosely—fromfullyimaginingthedamagedonealreadytotheplanet.Butwhenwedotrulyseetheworldwe’vemade,theysay,we
willalsofindawaytomakeitlivable.Forthem,thealternativeissimplyunimaginable.
*ThisarticleappearsintheJuly10,2017,issueofNewYorkMagazine.
*ThisarticlehasbeenupdatedtoclarifyareferencetoPeterBrannen’sTheEndsoftheWorld.
CONNECT:
©2017,NewYorkMediaLLC.