With respect to responding to challenges from climate change, the WCS Fiji program is primarily focused on adaptation to the perceived main climate hazards of tropical cyclones, floods, droughts, coastal erosion, and loss of coral reef habitat from coral bleaching. In order to provide appropriate recommendations to Fijian communities and government on which actions will be most effective to adapt management plans and structures to changing climatic conditions, we have reviewed the current state of knowledge of predicted climate impacts to the Fiji Islands and the South Pacific.
Current data indicate that while some aspects of climate-related environmental change in the region can be predicted with confidence, other areas remain highly uncertain. Data for air and sea surface temperature are reasonably robust. In Fiji, air temperatures have increased approximately 0.6 °C over the past 50 years (Fiji Meteorological Service, unpublished data). Surface air temperatures are predicted to increase by at least 2.5 °C by 2100 over the 1990 level (Lal 2004). Meanwhile, rainfall and tropical cyclone trends are less certain. Rainfall in Fiji has increased by approximately 10% during the wet season over the past 100 years, but there has been no corresponding increase during the dry season (Fiji Meteorological Service, unpublished data). Projections of future precipitation patterns are still unclear, with Intergovernmental Panel on Climate Change (IPCC) models indicating both increases and decreases in rainfall up to 10% over most small Pacific islands (Mimura et al. 2007). Scenarios for future tropical cyclone frequency and intensity are equally uncertain, with some models predicting no change and others predicting higher frequency or intensity (Mimura et al. 2007).
Given the high ratio of shoreline to land area across many South Pacific islands, coastal ecosystems and infrastructure are highly susceptible to damage from sea level rise. Long-term tide-gauge data between 1950 and 2001 from six island records show a mean rate of sea level rise of 2.0 mm yr-1 from monitoring sites across the tropical Pacific (Church et al. 2006), and partial assessments of the predicted impacts of sea level rise have been conducted for the largest island of Viti Levu (Gravelle and Mimura 2008). However, sea level rise impacts will not affect islands uniformly: for example, the Fiji Islands exhibited a diversity of tectonic processes throughout the Holocene and Quaternary with active uplifting, subsidence or maintenance of stable conditions occurring in different areas (Nunn and Peltier 2001). Moreover, it is often difficult to tease out effects of sea level rise from naturally occurring geomorphological processes that can and have been disrupted by anthropogenic alterations to coastlines (Webb and Kench 2010).
Because of data uncertainty and regional variability, development of accurate predictive models for the region has been challenging. A fine-scale (8 km horizontal resolution) regional climate model, the CSIRO Conformal-Cubic Atmospheric Model (C-CAM), has been recently used successfully to simulate past (1975-1984) annual maximum and minimum temperature and precipitation cycles at selected sites across Fiji (Lal et al. 2008) and has promise for locally-relevant future simulations. As new data on sea level rise are produced and used in conjunction with climate simulations from finer-scale models such as C-CAM, sector-specific vulnerability assessments for South Pacific Islands may become more robust. However, if judged by past records of climate policy development in the Pacific, even improved models may be of limited utility for decision making (Barnett and Campbell 2010). Instead, attention may be better focused on collating the large amount of existing data on social and environmental conditions that could be meaningfully used to assess vulnerability and adaptation to climate change in the region.
WCS Fiji is therefore focusing on managing for the predicted but uncertain impacts of flooding, drought, severe storms, coastal erosion and coral bleaching through implementation of community-based natural resource management strategies under an ecosystem-based management framework. At the same time, the WCS Fiji is increasing social capacity to adapt to climate fluctuations by strengthening community-based management structures, improving communications networks, and improving collaboration among a range of sectors and partners.
With respect to improving the resilience of Kubulau's coral reefs to climate-related disturbance, WCS Fiji adapted the reef resilience assessment methodology of Obura and Grimsditch (2009) to the local Fiji context. We are currently using data on a variety of reef indicators to design and reconfigure networks of marine protected areas (MPAs) to maximize future resistance to and resilience from climate disturbance while also spreading costs evenly among resource users. The recommendations for MPA placement will be coupled with recommendations for heightened protection across the entire fisheries management area of species such as grazers and top predators that confer higher resilience to reef communities.
Meanwhile, in order to reduce downstream impacts from climate-related flood disturbance, WCS Fiji and Wetlands International-Oceania (WIO) are closely collaborating to identify thresholds of land conversion beyond which downstream ecosystems are severely compromised. For example, a recent study by WCS Fiji and WIO demonstrated that loss of more than 50% catchment forest cover is associated with significant reductions in in-stream freshwater fish species richness, largely due to increased sedimentation (Jenkins et al. 2010). These effects are largely seasonal, with pronounced negative impacts during the wet season on biodiversity and food provisioning services in degraded catchments that will likely become more severe under predicted future climate scenarios (Jenkins and Jupiter 2011). WCS Fiji is using our science to develop recommendations for improved catchment management, including minimum sizes for riparian forest width, to preserve ecosystem integrity and essential services such as safe water provisioning.
To strengthen social resilience in Fijian land/seascapes, WCS Fiji, CORAL and Seaweb are piloting a new communications tool, the Community Educators Network Training, to help the local resource management committees deliver conservation and management messages to their constituents. Through tailored workshops, the management committee members learn how to draw upon traditional ecological knowledge as well as scientific information to empower them to communicate effectively in the village setting, particularly to target groups who have been previously under-represented in past management planning workshops, such as women and youth. To date, the training has resulted in increased enthusiasm for conservation, increased community organization, and improved awareness of how to mitigate threats to coastal and marine resources.
Finally, in order to assist communities to diversify sources of fuel, food and fiber, WCS is conducting surveys to document historical resource use patterns in response to past climate fluctuations in order to help communities modify behavior to adapt to future climate shifts. In addition, we have adapted the Community Risk Identification Tool-Adaptation and Livelihoods (CRiSTAL) to understand perceived threats from climate hazards and assess their impacts on community resources and local capacity to cope with climate disasters. Through these surveys, WCS Fiji will ensure that management plans developed with communities include appropriate disaster risk reduction activities.