prevenng dangerous climate change · – inacon and delay are costly

Preven&ngDangerousClimateChange

Session10NeilLearyChangingPlanetStudyGroupJune28–July1,2011

CoolingtheLiberalArtsCurriculumANASA‐GCCEFundedProject

Photo:RogerBraithwaite,UniversityofManchester

Ul&mateobjec&veofUNFCCC

•  Ar&cle2:“Theul&mateobjec&veofthisConven&on...istoachieve...

stabiliza&onofgreenhousegasconcentra&onsintheatmosphereatalevelthatwouldpreventdangerousanthropogenicinterferencewiththeclimatesystem.”

Source:IPCC2007WG2,Table20.8

Probabilityofovershoo&ng2°C(stabilisa&on)Meinshausen,2005,Scien&ficSymposiumonAvoidingDangerousClimateChange,Exeter,UK

JimHansen:mustaimlowerthan450ppm

SlidefromJ.Hansen’spresenta&ontoNa&onalPressClub,June2008

Hansen’sprescrip,onfor350target

1.PhaseOutCoalCO2Emissions‐by2025/2030developed/developingcountries

2.RisingCarbonPrice‐discouragesunconven,onalfossilfuels&extrac,onofeverylastdropofoil(Arc,c,etc.)

3.Soil&BiosphereCO2Sequestra,on‐improvedfarming&forestryprac,ces

4.Reducenon‐CO2Forcings‐reduceCH4,O3,tracegases,blacksoot

SlidefromJ.Hansen’spresenta&ontoNa&onalPressClub,June2008

TheEffectofDelay(sameriskofovershoo&ng)Meinshausen,2005

Howhardwillitbe?

Climatechangea‘wicked’problem

•  Wickedproblems:–  Unique,nodefini&veformula&on–  Incomplete,contradictoryinforma&on,changingrequirements–  Complexinterdependencies;afemptsatsolu&onscreateother

symptoms•  ClimatechangeisawickedproblemaccordingtoHulme

–  Wedisagreeonwhattheproblemis,onwhattheobjec&vesare–  Universal,top‐down,‘elegant’solu&onslikeKyotoProtocol

ineffec&ve–  Only‘clumsy’solu&onspossible?–  Maybenosolu&onispossible?

SmallGroups

A.  Whatlevelofwarmingisdangerous?B.  Candangerousclimatechangebeprevented?C.  Isauniversalagreementneededtoprevent

dangerousclimatechange?D.  ShouldstabilizingGHGconcentra&onstake

precedenceovereverythingelse?

Reportback:•  2thingsyourstudentsneedtolearn•  Howwilltheylearnthem?

Essen&alprinciplesofpreven&ngdangerousclimatechange(Or:whatshouldourstudentslearn?)

•  Climatechangeisawickedproblem;wedisagreeabout–  whatisdangerous–  Objec&ves&means–  Responsibili&es

•  Meanwhile,wearepokingabeastw/as&ck–  Climatesystemiscomplex,

nonlinear,chao&c–  Canchangeabruptly,

unpredictably,dangerously

•  Noamtofhumancausedclimatechangeisriskfree

•  StabilizingGHGconcentra&ons–  Noguaranteeofavoiding

dangerouswarming–  Requiresdeepemission

cuts–  istechnicallyfeasible,but

difficult&costly–  Inac&onanddelayare

costlytoo,anddangerous

Usefulresources

•  “TheCopenhagenDiagnosis,”Allisonetal,2009.UpdateofsciencesinceIPCC2007report,withfocuson‘dangerous’climatechange

•  JimHansen’swebsite:www.columbia.edu/~jeh1/.Accesshispapersandpresenta&ons.

•  “Howtoavoiddangerousclimatechange,”Luersetal,2007,reportfromUCS.

•  Schneideretal,2010.ClimateChangeScienceandPolicy.IslandPress.