Seite - 26 - in Loss and Damage from Climate Change - Concepts, Methods and Policy Options

26 R.Mechler et al. Theevidencebaseonclimateimpactsisgrowing.AssummarisedinIPCC’sAR5, impactsofclimatechangehavebeenobservedonallcontinentsandacrossalloceans. Thereishighconfidencethatworldwideglacialretreat,permafrostthawing,andmass bleaching of coral reefs can bemainly attributed to climate change (IPCC2014a). Yet, impacts tohumansystemsandspecificevents aremuchharder toassessdue to multifactorial causation, and inparticular, sincevulnerability reducingactionshave beenemployedinmanylocationsandformanyweather-relatedhazards(seechapters byBouwer2018;Lopezet al. 2018).Therefore, despite the advances, itmaynever bepossible togenerate a complete inventoryofL&Dattributable to anthropogenic emissions. Inaddition to theuncertainties inherent in theattributionproblem,a lack of robust time series data inmany hot spot locations hinders progress in research and riskmanagement (Huggel et al. 2016b). Thus, policy-advisors andnegotiators shouldnotexpecttheemergenceoffullyconclusiveevidenceregardingtheinfluence ofclimatevariability andchangeonspecific incidencesof lossesanddamagesand, in particular, should not expect the strength of evidence to be equivalent between events andbetweencountries. SomeofthemostfrequentlydiscussedapplicationsofattributionscienceforL&D have beenmade in relation to liability and legal responses.Attribution research is relevant to private and public administration litigation as well as to breaches of customary international law—theno-harmprinciple (see chapter bySimlinger and Mayer2018). In thecaseof litigationbefore anational or international court or tri- bunal, legal casesare facedwithamyriadof technicaldifficulties,particularlywhat concerns the issueof causality.Litigation requiresdiligence topreventorminimise harm, aswell as considering the indirect consequences of harmfulwrongdoing in additiontodirectimpacts,whicharenormallyconsideredinlitigation.Thus,thecase ofLliuyaversusRWE,which iscurrently (mid2018) in theevidentiary stagesafter having been admitted to a higher regional court inGermany, is exemplary in two regards. It isconsidered thefirstcaseonL&DinGermanyandelsewhere,asseveral tort-basedcaseshavebeenrejectedby, forexample, courts in theUSA. Italso inno- vatively seeks remuneration for riskmanagement efforts to be undertaken to avoid future, irreversible risk (loss of life) associatedwith glacial lake outburst flooding affectedbyglacial retreat attributedwithhigh confidence to anthropogenic climate change (see chapter byFrank et al. 2018).Given themany technical difficulties to be addressed, for legal actions overall, it may be interesting to consider working withaso-calledmodifiedgeneral causation test—ashasbeendonesuccessfully for other risk classes, such as tobacco, nuclear risk etc. (see chapter bySimlinger and Mayer2018).Thiswouldmeanfocusingonproving thatGHGemissionsaregener- ally capable of causingdamages and that a causal linkbetweenaction anddamage is probable. Such a rationale would render the requirement to attribute a specific climaticevent to theemissionsofaspecificpersonorentityunnecessary.Therefore, a lackofattributionevidencemaynotnecessarilybea limiting factor in some legal responses.Overall, attribution researchhas thepotential formuchbroader applica- bility. It has an important role toplay inhelping tounderstand losses anddamages, includingthroughthequantificationofrisks; investigatingtherelativeimportanceof differentdriversofchange; and identifying timescalesonwhichsignificant impacts