Seite - 264 - in Loss and Damage from Climate Change - Concepts, Methods and Policy Options

264 A.Lopezet al. 11.2 L&DfromaPhysicalSciencePointofView—The ChallengesofAssessing theRisk Risk is a functionof hazard, exposure andvulnerability. Therefore, any attempt of assessing the riskof losses anddamages fromclimate changeneeds to incorporate twokeycomponentsandillustratetheirinterplay:dataonvulnerabilityandexposure, aswell as informationon theclimatichazard, includingcurrent climaticvariability and future, long-termprojectionsofclimatechange (UNFCCC2008,2012a).From aphysical scienceperspective the focus is traditionally on thehazard side of risks, but there is a clear recognition that data needs and limitations for vulnerability and exposureassessmentsareequally important forunderstandingclimatechangerisks. The information about the climate hazard1 relates to the physical phenomena, such as large cyclonic storms or long-term reductions in precipitation, and their consequences, such as flooding or drought. This hazard information contains the input to estimate themagnitude and frequency of damagingmeteorological events inDRRapproaches,or toprojectchanges inclimate risks to informCCA.Fromthe physical sciences point of view, there are challenges to estimate the hazard part of the total riskcommon toall interpretationsofL&D. IPCC’sSREXconcludedwithhighconfidencethat increasingexposureofpeople and economic assets has been themajor cause of long-term increases in economic losses fromweather- and climate-related disasters, arguing that the development pathwaysofacountryorcommunitydoinfluenceexposureandvulnerability (IPCC 2012).But understanding the ‘multi-facetednature’ (IPCC2012) of both exposure andvulnerability is still a challenge, due todata limitations and the inherent uncer- taintyinsocio-economictrends(GAR2011).Thedatarequiredforassessingvulner- abilityandexposurevaries,dependingonscopeandcontext. Itcanincludehistorical loss information, property databases, demographic data,macroeconomic data such asdebt andfiscal budgets (UNFCCC2012a). In addition there are the intangibility aspectsofL&D,whicharenotvaluedbymarkets and thereforeareoften left outof any assessments. The ability to capture direct and indirect losses is also identified as a key challenge as highlighted at the 36th SubsidiaryBody for Implementation meeting inMay 2012, where it was noted that available estimates on losses typi- cally lacknumbersonnon-economic losses suchascultureandheritage (UNFCCC 2012b).Government asset databasesor sectorial disaster lossdata arenot available inall countries,or theymaybevery limited inscope,notcapturing those intangible impacts (Mechler et al. 2009). Thismakes assumptions and extrapolations neces- sary,which add to the degree of uncertainty forL&Dassessments. The chapter by Bouwer (2018) in thisbookdiscusses inmoredetail the interplaybetweenexposure and vulnerability and observed and expected losses due to anthropogenic climate change. 1Wenote that,while the IPCCAR5 refers to ‘physical impacts’ as the impacts of climate change on geophysical systems, including floods, droughts, and sea level rise, we use the term ‘hazard’ instead to refer to thephysical impacts.