No abstract

Small island developing states are vulnerable to the impacts of climate change, including more intense and frequent extreme weather, warming temperatures, coastal erosion, inundation, and coral bleaching. Locally-specific natural resource threats, associated with population growth and tourism, exacerbate these systemic risks, which are particularly acute where community well-being is subsistence-based and directly reliant on ecosystem services. Garden productivity is falling as the cropping/fallow cycle intensifies and culturally and there is loss of observance of traditional resource taboos, eroding the effectiveness of customary management. Ecosystem based adaptations (EbA) provide a fruitful range of interventions and are beginning to attract development funding. We undertook a social benefit cost analysis for a suite of interconnecting EbAs for Tanna in Vanuatu. We found that funds targeted at increasing the productivity of the gardens returns significant social benefit. This also reduces pressure on natural resource threats and can potentially be adopted by all households on Tanna. In addition, increasing the community's capacity to balance formal forest and reef conservation with customary management can provide small, but nevertheless important complimentary benefits. Our programme design included interlinking activities, including a series of demonstration garden plots, extension officers, community radio, a community ranger programme and a tree nursery.

Communities in Pacific small island states face a range of threats to their management of natural resources, exacerbated by change-related risks, all against the backdrop of social and economic transition. Ecosystem-based adaptation (EbA) describes a class of interventions that manage climatic change-related risks, which is argued to be relevant for such communities. Understanding local constraints and enabling conditions for EbA implementation is important in informing project implementation. We used Qmethodology to reveal principle discourses within a community in Vanuatu and among stakeholders with knowledge of the challenges confronting that community. We analysed stakeholders to determine whether particularly-held discourses correlate with demographic attributes. Our research revealed three principle discourses we called Strong Kastom, Kastom + Health and Tentative Modernity. Perspectives from each discourse need to be taken into account when identifying and evaluating adaptation options. Our results suggest adaptation interventions are more likely to resonate with the community if they support customary natural resource management, reflect traditional knowledge, provide opportunities for generating income, and promote gender equity in decision-making. Our results also suggest external practitioners do not necessarily consider income generation as being important to community livelihoods. Ignoring a community's perspectives, values, and priorities risks undermining the viability of EbA projects.

Climate change impacts, sea level rise, and changes to the frequency and intensity of storms, in particular, are projected to increase the coastal land and assets exposed to coastal erosion. The selection of appropriate adaptation strategies requires an understanding of the costs and how such costs will vary by the magnitude and timing of climate change impacts. By drawing comparisons between past events and climate change projections, it is possible to use experience of the way societies have responded to changes to coastal erosion to inform the costs and selection of adaptation strategies at the coastal settlement scale. The experience of implementing a coastal protection strategy for the Gold Coast’s southern beaches between 1964 and 1999 is compiled into a database of the timing, units, and cost of coastal protection works. Records of the change to shoreline position and characteristics of local beaches are analysed through the Bruun model to determine the implied sea level rise at the time each of the projects was completed. Finally, an economic model updates the project costs for the point in the future based on the projected timing of sea level rise and calculates a net present value (NPV) for implementing a protection strategy, per km, of sandy beach shoreline against each of the four representative concentration pathways (RCP) of the Intergovernmental Panel on Climate Change (IPCC) to 2100. A key finding of our study is the significant step-up in expected costs of implementing coastal protection between RCP 2.6 and RCP 8.5—from $573,792/km to $1.7 million/km, or a factor of nearly 3, using a social discount rate of 3%. This step-up is by a factor of more than 6 at a social discount rate of 1%. This step-up in projected costs should be of particular interest to agencies responsible for funding and building coastal defences.

Ecosystem service valuation (ESV) can inform land-use change policy and adaptation responses to climate change in Pacific Small Island Developing States. Despite Small Island Developing States communities relying acutely and directly on ecosystem service (ES) flows, methodologies must contend with limited valuation data and challenges. We undertake ESV to generate coefficients we then apply to mapped habitat extents for Vanuatu. We find the contribution of ESs to the people of Vanuatu is considerable and significantly larger than its gross domestic product. Therefore, policies that support ecologically sustainable exploitation of ESs are paramount in promoting community well-being. We also identify and discuss context-specific methodological challenges, which, if not addressed, risk distorting valuations, supporting perverse policy responses, and eroding confidence in ESV. We make recommendations to address the challenges of accounting for ecosystem condition, data gaps, and consideration of customary benefits, provide context to the interpretation of our results, and suggest where further research can ameliorate risks.