Page - 126 - in Loss and Damage from Climate Change - Concepts, Methods and Policy Options

126 R.A. Jameset al. distinctioninpolicy,betweenextremeeventsandslowonsetevents, isnotconsistent with theway the events are studied by scientists; and losses anddamages inmany cases result from the interplaybetween incremental change (including “slowonset processes”)andrare(extreme)events.Forinstance,sealevelriseisoftenexperienced throughanincreaseintheheightofstormsurges.Gradually increasingtemperatures mayhave their largest impactduringadrought. Attribution to anthropogenic climate change requires a comparisonbetween the influenceofhumanGHGsand the influenceofotherpotential drivers.Thefirst cli- matechangeattributionstudiescompared the“forcing”onglobal temperature from anthropogenic GHGs and aerosols, with natural drivers including solar variations andvolcanic aerosols (Tett et al. 1999;Stott et al. 2000).Attributionofglobal tem- perature also, importantly, considers the role of naturalmodes of variability, such as theElNinoSouthernOscillationorAtlanticMulti-DecadalOscillation(e.g.Fyfe et al. 2010;Foster andRahmstorf 2011;Follandet al. 2013),whichcanmodify the global temperature fromyear toyearor evendecade todecade (Parker et al. 2007). At a regionalor local scale, the roleofnatural variabilityonweather andclimate is evenmorepronounced,andit is thereforeaveryimportantfactor toconsider inattri- bution of losses and damages. In addition, the climatic and environmental hazards which lead to losses and damages havemany other drivers besides anthropogenic emissions and natural variability, for example changes in land use (such as defor- estation, urbanisation, agricultural development)which have important influences, for example via the hydrological cycle,meaningmore confoundingvariables need tobe taken intoaccount inanattributionanalysis. To understand losses and damages, it is essential to not only study drivers of environmental hazards, but also to investigate other components of risk: influences onexposureandvulnerability(Huggeletal.2013;chaptersbyBouwer2018;Schinko etal.2018;Lopezetal.2018;Botzenetal.2018).Theextentof lossesanddamages during aflood, for example,will be determined by the scale of themeteorological and hydrological hazard, but also the exposure of populations (are there people living in the floodplain?), and their vulnerability (are houses flood-resilient? are there early warning systems and procedures for emergency response? do people have insurance?).Furthermore, losses anddamagesmight includemonetary losses, lossoflife,damagetoinfrastructure,detrimentaleffectsonecosystems,andadiverse array of non-monetary or non-economic losses and damages (NELs/NELD), such as loss of identity, or psychological distress (Serdeczny et al. 2016; Clayton et al. 2017; chapter bySerdeczny 2018).Attribution of such a range of quantifiable and non-quantifiablevariablesposes furtheruncertainties andchallenges. Attributing losses anddamagesmaystart to sound likean impossible challenge. As wewill explore, it is not currently possible, and it may never be possible, to generateacompleteinventoryoflossesanddamagesfromanthropogenicemissions. Yet that shouldnotpreventscientists fromseeking todevelopafullerunderstanding of the drivers of losses and damages, and it does notmean that the science that is already available is not useful for policy-makers, who are accustomed to dealing with incomplete informationanduncertainties.Thereareseveral importantfieldsof enquirywhich can already contribute evidence to help us understand how anthro-