Climate change, impacts and vulnerability in Europe ... - MemoFin.fr

IntroductionAs a general rule, key messages are formulated atthe highest level of precision that is justified by theunderlying data. Furthermore, related statementswith different levels of precision (e.g. observationvs. projection) are clearly separated to indicate theprecision of each individual statement.Explicit information on the pedigree of informationand uncertaintyKey messages make explicit whether and howkey sources of uncertainty have been consideredin the underlying dataset wherever relevant andfeasible. For example, a key message on futureclimate change would indicate how many emissionsscenarios and climate models were considered toproduce the dataset.1.7 Definition of vulnerability and risk1.7.1 Diverse use of termsThe terms vulnerability and risk are often used todescribe the potential (adverse) effects of climatechange on ecosystems, infrastructure, economicsectors, social groups, communities and regions.These terms are attractive because they are bothintuitively understandable to a large audience androoted in several scholarly communities contributingto climate change impact, vulnerability and riskassessments. However, the fact that these termsare used rather differently across, and sometimeswithin these scholarly communities, can give riseto misunderstandings (Füssel, 2007; O'Brien et al.,2007). In general, use of the terms vulnerability andrisk is unproblematic if they are applied in a rathergeneric, intuitive sense. However, whenever one ofthese terms is used quantitatively (e.g. to comparethe vulnerability of different regions or populationgroups) or to advise on suitable actions to reducevulnerability or risk, it is necessary to specify clearlyhow the term is understood.This EEA report includes contributions that use theterm vulnerability according to its use in the climatechange, disaster risk and public health communities.The distinction between the various concepts isexplained below and also in the IPCC SREX (IPCC,2012).The EEA accepts the existence of various definitionsand interpretations of vulnerability and risks inclimate change science and policy. The approach inthis report was therefore not to choose one specificdefinition of vulnerability and risk over others but toprovide further clarification where needed. Hence,the use of these terms in this report always followsthe underlying literature, and further explanation isprovided where needed.The term vulnerability is generally used to describethat a valued characteristic of a system (e.g. theincome basis of a community or the carbon stock ofa forest ecosystem) is threatened due to exposureto one or more stressors (e.g. extreme weatherevents or long-term climate change). Different usesof vulnerability in the climate change context aredistinguished by the following factors:• whether they consider only internalcharacteristics of the vulnerable system or alsocharacteristics of the external stressor(s) it isexposed to;• whether they refer to human systems, naturalsystems, coupled human-environment systemsand/or built infrastructure;• whether they consider only short-onset events(e.g. tropical cyclones) or also continuouschanges (e.g. long-term changes in meantemperature);• whether they consider climate change inisolation or together with other environmentaland/or socio‐economic developments;• the level of aggregation and the extent of valuejudgements required for doing so (e.g. foraggregating market and non‐market impacts, foraggregating impacts affecting different groupsof people at different points in time, and foraggregating impact projections associated withdifferent levels of uncertainty);• the level of quantification (e.g. high/medium/low vs. exact numbers).1.7.2 'Outcome' interpretation of vulnerability toclimate changeThe IPCC in its AR4 defined vulnerability (toclimate change) as follows: 'Vulnerability is afunction of the character, magnitude, and rate of climatechange and variation to which a system is exposed,its sensitivity, and its adaptive capacity.' (IPCC,2007b, p. 883) (see Figure 1.2). According to thisdefinition, vulnerability is an integrated measureof the expected magnitude of adverse effects to asystem caused by a given level of certain externalstressors, taking into account feasible adaptation.Climate change, impacts and vulnerability in Europe 201245