Page - 269 - in Loss and Damage from Climate Change - Concepts, Methods and Policy Options

11 TheRoleof thePhysicalSciences inLossandDamage… 269 Fig.11.1 The uncertainty cascade in the modelling chain from climate model forcings to the estimation of the climate hazard (the physical impact of climate change). An estimation of the total riskshould includevulnerabilityandexposurescenarios that, incombinationwith theclimate hazard as inputs for an impactmodel, outputs the total impact on, for instance, lives, livelihoods, health, ecosystems, economies, societies, cultures, services, and infrastructure discussed,climatemodelshavesignificant limitationstosimulatetheclimatesystem at the scales relevant forextrememeteorological events (Trenberth2012;Trenberth andFasullo 2012). Therefore, an evaluation of the climatemodel skill (Stott et al. 2017) and the statistical reliability of themodel-based probabilities (Bellprat and Doblas-Reyes2016;Weisheimer et al. 2017) shouldbecarriedout to ensure robust estimates of attributable changes in climate hazards. For a detailed discussion on attributionwerefer the reader to thechapterbyJameset al. (2018) in thisbook. In summary, a comprehensive modelling approach to assess climate change inducedhazardsrequires thecombinedsimulationofall thedomains.Forfloodrisk, for instance, it requires themodellingof theatmosphereandocean, catchment river network, flood plains and indirectly affected areas. As discussed above, and illus- trated inFig. 11.1, considerable uncertainty is introduced in eachof themodelling steps involved, including uncertainties about the greenhouse gas concentrations’ scenarios, the representationof physical processes in theglobal climatemodel, the characterisationofnaturalvariability,themethodofdownscalingtocatchmentscales and thehydrological and inundationmodels’ structuresandparameterizations.