Small islands addressing climate change: towards storylines of risk and adaptation – STORISK

The STORISK project involves 10 research teams having complementary disciplinary skills and using contrasting methods applying from the global scale (e.g., climate-ocean interactions modelling) to the local scale (estimation of the local impacts of climate change). One of the major challenges of this project is precisely to proceed to a co-construction of knowledge and cross-analysis of the data generated so as to provide robust knowledge on the possible futures of the Small Tropical Islands of the Indian and Pacific oceans. In this perspective, this project builds on both physical modelling and fieldwork, the latter being based on a case study approach. Case studies (Reunion Island, French Polynesia islands) are representative of the diversity of situations of French Small Islands, and they are complemented with a comparative analysis of French islands with other island territories (the Seychelles Islands, the Cook Islands and Kiribati) so as to guarantee the significant character of the results generated at the scale of Small Islands on the whole. The main methods used are climate-ocean interactions modelling, the estimation and attribution of sea level variations at different timescales, marine inundation modelling, modelling of the multi-centennial response of atoll reef islands to climate change-induced pressures, the completion of island topographic surveys including digital elevation models, the reconstruction of the trajectories of vulnerability of studied areas based on a multi-criteria approach, the reconstruction of chains of impacts of past climate-related events, the design of chains of risks of impacts of climate change, the completion of population surveys on the perception of coastal risks and climate change and of semi-structured interviews with concerned stakeholders, the co-organization with local partners of workshops for knowledge dissemination and for the co-construction of scenarios of possible island futures.

The STORISK project aims at producing the following results:
1. Develop a transdisciplinary methodological protocol to study climate-change related risks, based on the reconstruction of Trajectories of vulnerability and Chains of Impacts of extreme climate events and gradual climate-induced environmental changes.
2. Identify the drivers of Small Islands future vulnerability, paying a specific attention to under-researched drivers, such as ENSO, distant-source swells and ecological changes driving the coral growth.
3. Attribute the observed impacts at the local scale to specific drivers, i.e. climate variability or change, or natural vs. anthropogenic factors.
4. Highlight the diversity of the vulnerability profiles of small islands in the face of ocean climate-related hazards under climate change, as this is a key step to design appropriate adaptation strategies.
5. Move forward more robust scenarios on future storylines of risk, based on the consideration of changes not only in physical and environmental conditions, but also in societal parameters. The latter are under-researchers and under-considered, which constitutes a major research gap when addressing human societies' future.
6. Refine the understanding of uncertainty on the future impacts of climate change, in order to help reducing the weight of uncertainty in prospective approaches and thus allow the science/decision dialogues to move a step forward.
7. Develop an analytical framework to assess the risk of maladaptation and design, in close collaboration with stakeholders, context-specific trajectories of adaptation to climate change.
8. Strengthen collaboration with the decision-makers and practitioners involved in risk reduction and adaptation to climate change from the local to the national scale.

Based on these results, the STORISK team aims to bring key insights on:
- the clarification of the concrete risks of impacts of climate change at a local scale, which would not only improve knowledge, but also bring a major support to decision-making;
- the design of a robust typology of small islands highlighting differentiated vulnerability profiles in the face of climate change;
- the design of generic models of impacts highlighting the factors and processes driving the current and future impacts of climate change, and the major levers and barriers to be considered to reduce impacts;
- supporting risk reduction policies and adaptation to climate change strategies in French overseas territories, by bringing key insights on their current applicability and on their possible adaptations to the specific contexts of overseas territories.
Based on these elements, two major prospects are first, to make French research on Small Islands more visible at the international level, and second, to support the French public authorities in the design of risk reduction policies and adaptation to climate change strategies, which will also help building French leadership at the international level.

DUVAT V.K.E., MAGNAN A., 2017. Hurricanes: rescue natural Defences. Nature, vol. 550, 43, doi: 10.1038/550043b.
DUVAT V., MAGNAN A., WISE R., HAY J., FAZEY I., HINKEL J., STOJANOVIC T., YAMANO H., BALLU V., 2017. Trajectories of exposure and vulnerability of small islands to climate change. WIREs Climate Change, e478. doi: 10.1002/wcc.478
DUVAT V., SALVAT B., SALMON C., 2017. Drivers of shoreline change in atoll reef islands of the Tuamotu Archipelago, French Polynesia, Global and Planetary Change, 158, 134-154. doi: 10.1016/j.gloplacha.2017.09.016
DUVAT V., PILLET V., 2017. Shoreline changes in reef islands of the Central Pacific: Takapoto Atoll, Northern Tuamotu, French Polynesia. Geomorphology, 282: 96-118. doi: 10.1016/j.geomorph.2017.01.002
DUVAT V., VOLTO N., SALMON C., 2017. The impacts of Category 5 Tropical Cyclone Fantala (April 2016) on Farquhar Atoll, Seychelles Islands, Geomorphology, 298, 41-62. doi: 10.1016/j.geomorph.2017.09.022
GATTUSO J.-P., MAGNAN A.K., 2017. Océan : les risques liés au climat. pp. 220-221 In A. Euzen, F. Gaill, D. Lacroix, P. Cury (Dir.) – L’océan à découvert, CNRS Éditions, Paris, ISBN 978-2-271-11652-9.
EDMUNDS P. J., COMEAU S., LANTZ C., ANDERSSON A., BRIGGS C., COHEN A., GATTUSO J.-P., GRADY J. M., GROSS K., JOHNSON M., MULLER E. B., RIES J. B., TAMBUTTÉ S., TAMBUTTÉ E., VENN A., CARPENTER R. C., 2016. Integrating the effects of ocean acidification across functional scales on tropical coral reefs. BioScience 66, 350-362.
DUVAT V., MAGNAN A., ETIENNE S., SALMON C., PIGNON-MUSSAUD C., 2016. Assessing the impacts of and resilience to Tropical Cyclone Bejisa, Reunion Island (Indian Ocean), Natural Hazards, 83: 601-640. doi: 10.1007/s11069-016-2338-5
MAGNAN A.K., DUVAT V.K.E., 2016. Trajectoires de vulnérabilité et adaptation au changement climatique à la Réunion. Policy Brief Iddri n°08/16/Climat, 4 p.

The STORISK project (48 months) aims to develop a transdisciplinary and innovative methodological protocol to improve knowledge and understanding of small island societies’ vulnerabilities and adaptive capacities to the impacts of both climate-related extreme events (i.e., tropical cyclones, distant-source swells and ENSO) and gradual changes in climate/ocean parameters (i.e., sea level rise, ocean warming and acidification).
In this perspective, this project relies on two complementary approaches based on concepts developed by its main contributing teams, those of Chains of impacts and Trajectories of vulnerability, which have led to the development of a first methodological protocol that will be refined in STORISK. This protocol will allow the reconstruction of both comprehensive Chains of impacts of climate-related extreme events and climate change, and of Trajectories of vulnerability for small tropical islands (both mountainous and low-lying). These two approaches are complementary, as the former allows apprehend vulnerability through an in-depth analysis of the impacts of extreme events (including resilience) while the latter focuses on a territory’s development to capture, through the analysis of its strengths and weaknesses, the root causes of its vulnerability. The key hypothesis on which the STORISK project is based on is that small islands have differentiated vulnerability profiles and will therefore experience diversified “storylines of risk” under climate change.
The two key scientific challenges of this methodological development are first, to integrate in a coherent way all research areas concerned with the assessment of current and future risks (from climate and marine inundation modelling to risk perception and to the assessment of the risk of maladaptation), and second to consider and evaluate uncertainty (i.e., sources, extent and implications on island systems’ vulnerability) in order to build realistic scenarios at the local scale. Based on a dynamic approach of vulnerability (i.e., reconstructing trajectories of vulnerability on empirical bases instead of considering the current state of vulnerability) integrating both the driving factors and processes controlling changes in vulnerability, STORISK intends to move knowledge (and methodologies) on future vulnerability a step forward. Beyond its specific benefits for the selected small islands, it will indeed bring more general outcomes on how to apprehend future vulnerability to support the design of robust adaptation strategies in coastal areas at large.
The STORISK approach will thus allow translate both current climate-related risks and future risks induced by climate change in “storylines of risk”. These concrete and robust “storylines” that are rooted in the past and current features of small islands will allow engage a fruitful dialogue with local to national and regional stakeholders on risk reduction strategies and adaptation pathways.
This project mainly focuses on French overseas territories of the South-Western Indian Ocean (Reunion Island and the Eparses Islands) and the Central Pacific Ocean (French Polynesia). It considers both undisturbed and little disturbed environments (i.e., uninhabited and rural settings) and highly disturbed environments (atoll capitals) to better investigate the contribution of nature- and human-related drivers to island vulnerability and to highlight the high diversity of island systems and of their future responses to climate stressors in a changing climate. Because the results obtained from case studies will be put into perspective with the situation of neighbouring islands, STORISK will bring general insights on the situation of small islands.