10Food Security and Adaptation to Climate Change W

133BookID182985_ChapID8_Proof#1-10/10/2009AbstractThepotentialforagriculturalsystemstoadapttoclimatechangeisatoncebothpromisingandpoorlyunderstood.Thischapterreviewspossiblepro-ducerandconsumerresponsestoachangingclimate,theabilityoftheseresponsestooffsetotherwisenegativeimpactsonfoodsecurity,andtheroleofpublicandprivateinstitutionsininvestinginadaptationwhereindividualresponsesareinsuf-ficient.Accumulatedevidencesuggeststhatwealthiersocietiesandhouseholdswillbebetterabletoadapttoachangingclimatebecauseoftheirgreateravailabilityofalternativesandtheirabilitytotakeadvantageofthem.Accordingly,investmentsthatimproveoptionsforthepoor,suchasimprovedagriculturalproductiontech-nologies,financialinstruments,andoff-farmincomeopportunities,willlikelybecriticalforadaptingfoodsecuritytoachangingclimate.8.1IntroductionClimatechangewillnotconfrontastaticworld.Humansrespondtochangesintheirnaturalandeconomicenvironmentandoftenmakethemselvesbetteroffbydoingso,aresponsivenessclearlyevidentinagriculture.Ashumanpopulationsgrewandspreadoverpastmillennia,foodproductionwasexpandedintofarcornersoftheworld,feedinggrowingpopulationsinstrikinglydiverseenvironmentsandclimates.Thisabilityofhumanitytoadaptagriculturetonewclimatesisevidencetomanythatclimatechangeposesnofundamentalthreattoagriculture–thatcleverhumans,asincenturiespast,willsimplyadaptagriculturetoitsnewgrowingconditions.Butthemagnitudeandspeedofclimatechangethatisexpectedoverthenextcenturyraisesseriousquestionsabouthowmuchagriculturecanbeadaptedtonewclimates,howquickly,andatwhatcost.Willsimplefarm-levelmeasuressuchasswitchingcropvarietiesbeenoughtooffsetexpectedlossesinmuchoftheworld?OrwilllargerinvestmentsincropbreedingorirrigationinfrastructurebeneededtomeetChapter8FoodSecurityandAdaptationtoClimateChange:WhatDoWeKnow?MarshallBurkeandDavidLobellD.LobellandM.Burke(eds.),ClimateChangeandFoodSecurity,AdvancesinGlobalChangeResearch37,DOI10.1007/978-90-481-2953-9_8,©SpringerScience+BusinessMedia,B.V.200M.Burke()andD.LobellStanfordUniversity,CA,USA1134M.BurkeandD.LobellBookID182985_ChapID8_Proof#1-10/10/2009BookID182985_ChapID8_Proof#1-10/10/2009thefoodneedsofagrowingglobalpopulation?Orcouldeventheseeffortsfallshort?Suchquestionsarecentraltobothanticipatingthefullimpactsofclimatechangeonfoodsecurityandhumanlivelihoods,andinplanningappropriateresponses.Thischapterwillexplorepotentialadaptationstoclimatechangethatmightimprovefoodsecurity,where“adaptation”isunderstoodtomeananyresponsethatimprovesanoutcome(ReillyandSchimmelpfennig2000).Manypossibleadapta-tionsinvolvedirectchangestoagriculturalsystems,suchaschangingwhenandwherecropsaregrown.Butbecausefoodsecurityinvolvesmuchmorethanjustfoodproduction(Chapter2),wealsoconsidervariousbroaderresponsestoclimatechangethatmightimprovefoodsecurity,suchasimprovingsocialsafetynetsthatprotectthepoorinadverseyears.Ofcentralinterestisthepotentialofthesemeasurestooffsetmanyoftheantici-patednegativeeffectsofclimatechangeonfoodsecurity,andinparticulartheextenttowhichsuchadaptationswillhappenmoreorlessontheirown(socalled‘autono-mousadaptation’)asopposedtorequiringsignificantinvestmentandforesightforthemtooccur(‘plannedadaptation’).Forinstance,ifweexpectfarmerstoautomati-callyrecognizeclimateshiftsandreactinwaysthatoffsetexpectedlosses,thentheneedforoutsideinvestmentandpolicyinterventioninadaptationissmall.Butifweexpectfarmerstohavetroublerespondingontheirown,andthatthisinabilityappearstothreatenglobalorregionalfoodsecurity,thentherewouldseemapress-ingneedtounderstandwhatbroaderinvestmentsinadaptationwouldberequired.Unfortunately,thereislittleexistingquantitativeevidenceontheabilityofadap-tationtoimprovefoodsecurityoutcomesinthefaceofclimatechange,withlargeuncertaintiessurroundingboththepotentialgainsfromvariousadaptationmea-suresandtheextenttowhichtheywillbeundertakenautonomously.Particularlydifficultisdisentanglingtherelationshipbetweenfarmerresponsestoclimatevari-ability,whichoccurcontinually,andtheirlikelylongerrunresponsestochangesinmeanclimate.Belowwereviewtheexistingtheoryandevidencesurroundingagri-culturaladaptationtoclimatechange,andattempttodrawlessonsbothforinvest-mentprioritiesandforfutureresearchneeds.8.2FarmerAdaptationtoClimate:DealingwithVariabilityTheexplicitfocusofthisbookisonclimatechange–i.e.thepotentialshiftsinthelonger-runmeanandextremesoftemperature,precipitation,andothermeteorologi-calvariablesinagivenarea.Andwhilelonger-runclimateexertssignificantinflu-enceonagriculturaldecision-making,affectingwhatcropsfarmersgrowandwhenandwheretheygrowthem,theactualamountoffoodproducedinagivenyeardependsonthespecificrealizationofmeteorologicalvariablesinthatyear.Year-to-yearchangesinthesevariables(or“climatevariability”)playacentralroleinglobalandregionalfoodsystemsandinfoodsecurityoutcomes.Asaresult,climatevariabilitycanbothilluminateandconstrainpossiblelonger-runadaptationtoclimatechange.Forinstance,farmerandfoodsystemresponsestopastweathereventsaresomeoftheonlyevidencewehavetounderstandhow1358FoodSecurityandAdaptationtoClimateChange:Wha