Trajectories of exposure and vulnerability of small islands to climate change

The authors thank the funding and logistical supports for the Back to the Future workshop (France, October 8–10, 2013) provided by the Corderie Royale de Rochefort, the Regional Council of Poitou-Charentes, the Conservatoire du Littoral, the Fondation de France, the Club Méditerranée, the Communautés d'agglomération de La Rochelle et du Pays Rochefortais, and the Université populaire du Littoral Charentais 17 and the French National Research Agency (CapAdapt project, ANR-2011-JSH1-004 01 and STORISK project, ANR-15-CE03-0003).This article advocates for a dynamic and comprehensive understanding of vulnerability to climate-related environmental changes in order to feed the design of adaptation future pathways. It uses the trajectory of exposure and vulnerability (TEV) approach that it defines as ‘storylines of driving factors and processes that have influenced past and present territorial system exposure and vulnerability to impacts associated with climate variability and change.’ The study is based on the analysis of six peer-reviewed Pacific island case studies covering various geographical settings (high islands vs low-lying reef islands, urban vs rural) and hazards associated with climate variability and change; that addressed the interactions between natural and anthropogenic driving factors; and adopted multidecadal past-to-present approaches. The findings emphasize that most urban and rural reef and high islands have undergone increasing exposure and vulnerability as a result of major changes in settlement and demographic patterns, lifestyles and economies, natural resources availability, and environmental conditions. The article highlights three generic and successive periods of change in the studied islands’ TEV: from geopolitical and political over the colonization-to-political independence period; to demographic, socio-economic, and cultural from the 1960s to the 1980s; culminating in the dominance of demographic, socio-economic, cultural, and environmental drivers since the 1980s. Based on these empirical insights, the article emphasizes the existence of anthropogenic-driven path-dependency effects in TEV, thus arguing for the analysis of the temporal dimensions of exposure and vulnerability to be a prerequisite for science to be able to inform policy- and decision-making processes toward robust adaptation pathways.PostprintPeer reviewe

Habitability of low-lying socio-ecological systems under a changing climate

Funder: Prince Albert II of Monaco Foundation; doi: http://dx.doi.org/10.13039/501100011592Funder: International Atomic Energy Agency; doi: http://dx.doi.org/10.13039/501100004493Funder: Institut de Recherche pour le Développement; doi: http://dx.doi.org/10.13039/100012947Climate change will push the planet worryingly close to its boundaries, across all latitudes and levels of development. One question therefore is the extent to which climate change does (and will) severely affect societies’ livelihoods, health, well-being, and cultures. This paper discusses the “severe climate risks” concept developed under Working Group II’s contribution to the Fifth and Sixth Assessment Reports of the Intergovernmental Panel on Climate Change (IPCC, AR5, and AR6). Focusing on low-lying coastal socio-ecological systems (LCS) and acknowledging that attempts to define “severe” climate risk have been problematic at the level of global syntheses, we argue for a more place- and people-based framing relating to “habitability under a changing climate.” We summarize habitability in terms of five habitability pillars: land, freshwater, food, settlement and infrastructure, and economic and subsistence activities; we acknowledge social and cultural factors (including perceptions, values, governance arrangements, human agency, power structures) as critical underlying factors rather than as separate pillars. We further develop the habitability framing and examine climate risk to future human health and habitability for three climate “hotspot” archetypes (arctic coasts, atoll islands, densely populated urban areas). Building on the IPCC AR6 framing of severe climate risks, we discuss three key parameters describing severe climate risks in LCS: the point of irreversibility of changes, physical and socio-ecological thresholds, and cascading effects across various habitability dimensions. We also highlight the variability of severe risk conditions both between coastal archetypes and within each of them. Further work should consist of refining the case study framing to find the right balance between capturing context-specificities through real-world local case studies and commonalities derived from more generic archetypes. In addition, there is a need to identify appropriate methods to assess irreversibility, thresholds, and cascading effects, and thus severe climate risks to habitability

Status of global coastal adaptation

The state of progress toward climate adaptation is currently unclear. Here, we apply a structured expert judgement to assess multiple dimensions shaping adaptation (equally weighted: risk knowledge, planning, action, capacities, evidence on risk reduction, long-term pathway strategies). We apply this approach to 61 local coastal case studies clustered into four urban and rural archetypes, to develop a locally-informed perspective on the state of global coastal adaptation. We show with medium confidence that today’s global coastal adaptation is half-way to the full adaptation potential. Urban archetypes generally score higher than rural ones (with a wide spread of local situations), adaptation efforts are unbalanced across the assessment dimensions, and strategizing for long-term pathways remains limited. The results provide a multi-dimensional and locally-grounded assessment of global coastal adaptation, and lay new foundations for international climate negotiations by showing that there is room to refine global adaptation targets and identifying priorities transcending development levels