prevenng dangerous climate change · – inacon and delay are costly
TRANSCRIPT
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.