Seite - 226 - in Loss and Damage from Climate Change - Concepts, Methods and Policy Options

226 K.vanderGeest et al. 9.3 ImpactsofClimateChangeonEcosystem Services-CurrentKnowledge Ecosystems are collections ofmacro andmicroscopic biota that form critical life support systems. Degradation of ecosystems is occurringworldwide due to over- exploitation and because of insufficient recognition of the vital importance of the services that ecosystems provide to humanwell-being (WWAP2015;MA2005). Climate change has the potential to exacerbate ecosystemdegradation and reduce the efficiency of ecosystem services (Staudinger et al. 2012; Bangash et al. 2013; Lorencováet al. 2013). TheMillenniumEcosystemAssessmentdefinesecosystemservicesas thebene- fits that people obtain fromecosystems (MA2005) anddistinguishes four types of ecosystemservices : • provisioningservices (food,water, fuel andwoodorfiber), • regulatingservices (climate,floodanddisease regulationandwaterpurification), • supportingservices (soil formation,nutrient cyclingandprimaryproduction), • cultural services (educational, recreational, aesthetic andspiritual). Thequalityofecosystemservicesincreaseswiththelevelof intactness,complex- ity, and/or species richness of ecosystems (Díaz et al. 2006).Manyof the negative consequences human societies experience from climate change are related to the adaptationlimitsof individualspecies thatprovideuswithfood,fiber, fuelandshel- ter, aswell as the services provided bywhole ecosystems.Dowand others (2013) provide two telling examples of such adaptation limits. First, there is a limit to the temperature that rice in SouthAsia can copewith in the pollination andflowering phase: After a threshold temperature of 26 °C, every 1 °C increase in night-time temperatureresults ina10%declineinyield.Beyondanight temperatureof35°Cit is impossible togrowcurrentricevarieties there,whichconstitutesahardadaptation limit beyondwhich different types actors (farmers, traders, the economy at large) incur lossesanddamagesduetochanges intheecosystemservice(Dowetal.2013). The secondexampledemonstrateshowasociety itself canchoose its adaptation limits:AftersettlinginGreenlandaround1000AD,thecomplexandadvancedNorse society thereendedaround1450.Thesettlements’collapsecanbeattributed to their adaptation limits.When harsh conditions began,NorseGreenlanders adopted new ways of exploitingmarinemammals as declines in agriculture and domestic live- stockproductionpersisted.But facedwithgrowingcompetition fromInuit hunters, declining trade in ivory and furwithNorway as pack ice blocked their access, and agenerally chillingclimate, these adaptationswere insufficient tomaintain risks to communitycontinuityattolerablelevels.Atthesametime,theNorsesettlersrefused toadopt techniques thatproveduseful to the Inuit (Dowetal.2013). Impactsofcli- mate change on ecosystem services are characterised byhigh levels of complexity arising from interactions of biophysical, economic, political, and social factors at variousscales(Ewertetal.2015).Theseimpactsareoftenspecifictoagivencontext orplace,makinggeneralisationsdifficult.