Seite - 125 - in Loss and Damage from Climate Change - Concepts, Methods and Policy Options

5 Attribution:HowIs ItRelevant forLoss… 125 uncertaintywill alwaysremain,and it is important tohelp thesestakeholdersunder- standwhat thesciencemightbeable tooffer, andwhere itmightbe insufficient.On the other hand,manyother stakeholders highlighted the challenges anddifficulties of attribution,24 some even saying that it is impossible,25 which perhapsmisses an opportunity,as theremaybeuseful researchavailablewhich theyareunawareof. In thenext section,we reviewsourcesof attributionevidence toexamine theextent to which theymight provideuseful information about the changing riskof losses and damages. 5.3 TheScienceofAttribution:WhatKindofEvidenceIs AvailableAbout theInfluenceofAnthropogenic ClimateChangeonL&D? Climate change attribution research initially focused on investigating drivers of observed globalwarming (e.g. Tett et al. 1999; Stott et al. 2000). However global meansurface temperaturedoesnothavedirect influenceonpeopleor infrastructure. Attributionof losses anddamages is amuchmorechallengingandmore interdisci- plinary scientificproblem. Attributing lossesanddamages involves investigatinghowanthropogenicGHGs influence many other climatic variables besides global temperature, as well as their influence on the oceans, cryosphere and biosphere, on a range of timescales. UNFCCCdocuments (e.g.UNFCCC2013, 2015) consistently state that losses and damages refers to impacts from both extreme events (including heatwaves, flood- ing, tropical cyclones, anddrought), and “slowonset” events or climatic processes (including glacier retreat, sea level rise, ocean acidification and desertification).26 Understandingthiswiderangeofenvironmentalprocessesrequiresinputfrommany different scientificdisciplines (fromphysical climatescience, tohydrology, toecol- ogy, toeconomics),andcollaborationbetweenthem.It isworthhighlightingthat the describedattribution scienceas thekey tounlocking liability, implying that itwould later emerge: “we don’t have to enter the rooms on liability and compensation, those doors are locked behind a door called attribution. The key to that door lieswith the scientific community, it is still being forged.” 24For example: “Attribution is just really difficult,” “asweknowattribution is verydifficult,” and “thewholeattribution thing is tricky.” 25On being askedwhether L&D should refer to L&Dwhich can be attributed to anthropogenic climate change, or all climate-related L&D, one interviewee said “there’s no science that can distinguishbetweenthetwo,”andanothersaid“I thinkinmanycases, it’s justsimplyimpossible to differentiatebetween the two.AndIcannot thinkaboutonemethodology thatwouldallowasmall islandstate toarguewhether a stormsurge ispart of anaturalvariabilityor climatechange.” 26In decision 1/CP.16 (UNFCCC2011), itwas noted that approaches to address losses and dam- ages should consider climatic impacts “including sea level rise, increasing temperatures, ocean acidification, glacial retreat and related impacts, salinization, land and forest degradation, loss of biodiversityanddesertification”