17.2.9.1. Settlement and Infrastructure

In most small island states (including high islands such as Seychelles, Reunion, and Fiji), narrow coastal plains provide attractive locations for settlement and a variety of infrastructure to support economic and social needs. Most of the population, settlements, and economic activities are concentrated in areas where competition for space is acute and where fragile ecosystems, aquatic and terrestrial, coexist. In most Caribbean islands, for example, more than 50% of the population live within 2 km of the coast. On atolls, most of the important infrastructure and population clusters often are less than 100 m from the shoreline. As the shortage of coastal space becomes increasingly acute in many small islands, land reclamation often is practiced as a solution to this need. Ironically, this practice exposes these islands to greater risk by attracting more settlement and infrastructure to already highly vulnerable locations.

As elsewhere, coastal development in most small islands has been undertaken in the past without taking climate change and sea-level projections into consideration. With currently projected rates of sea-level rise and flooding, coupled with the possibility of more intense and frequent extreme events such as cyclones (hurricanes) and associated storm surge, critical infrastructure such as social services, airports, port facilities, roads, coastal protection structures, tourism facilities, and vital utilities will be at severe risk. Furthermore, the capacity of most small island states to respond effectively to these threats is limited by their low adaptive capacity, which results from a combination of factors—including physical size (little opportunity to retreat), limited access to capital and technology, and a shortage of human resource skills.

In some countries, particularly the low islands and micro-atolls, resettlement within national boundaries may have to be considered as the only viable option. However, implementation of this strategy could become extremely complicated, especially for densely populated coastal lowlands such as in the Federated States of Micronesia (950 persons km^-2), Majuro, Marshall Islands (2,188 persons km^-2) and Male, Republic of Maldives (35,000 persons km^-2). In extreme circumstances, it may even become necessary to abandon some atolls altogether (Nurse et al., 1998). Such an option would be socially and culturally disruptive and would require access to substantial resources—which most of these countries may be unable to afford.

17.2.9.2. Human Health

Increased instability of weather patterns and large interannual variability in climate enhanced by ENSO forcing and GHG-induced climate change have catalyzed a new focus on possible health consequences in a changing climate (Epstein, 1997; Epstein et al., 1997; Hales et al., 1997; Woodward et al., 1998). Many tropical islands are now experiencing high incidences of vector- and water-borne diseases that are attributed to changes in temperature and rainfall regimes, which may be linked to events such as ENSO, droughts, and floods. In the Pacific, there is growing evidence that outbreaks of dengue are becoming more frequent and appear to be strongly correlated with the ENSO phenomenon (Hales et al., 1997, 1999a). Many of the small island states lie in the tropical zone, where the climate is suitable for the transmission of tropical diseases such as malaria, dengue, filariasis, and schistosomiasis.

Some of the small island states, such as the Bahamas, Kiribati, the Marshall Islands, and the Maldives, are a mere 3-4 m above mean sea level, which predisposes them to inundation with seawater and, as a consequence, salinization of freshwater supplies and flooding from sea-level rise. Furthermore, low-lying islands are particularly vulnerable to storms and cyclones; these also can adversely affect public water supplies. Vector-borne diseases such as malaria and dengue are particularly sensitive to warming and flooding. Filariasis and schistosomiasis are less sensitive to short-term seasonal climatic changes, but the epidemiology of these diseases could change with long-term effects of climate change. Water-borne diseases such as shigella, cryptosporidium, giardia, and amoebiasis could increase as a result of disruption of sewage and water systems by flooding (see Chapter 9).

It is also projected that, with temperature and rainfall changes, some vectors could extend their range, so there is likely to be wider transmission of some diseases (McMichael, 1996). For example, malaria—which previously tended to be confined largely to the western and central Pacific region—now appears to be extending east as far as Fiji. It also is worth noting that the interior uplands of many islands, which now are virtually free of vectors (e.g., Aedes aegypti mosquito) that transmit malaria, dengue, and other tropical illnesses—could become favorable breeding sites in a changing climate (disease-specific details appear in Chapter 9).

In some regions—for example, the Pacific—it has been noted that extreme weather events appear to be occurring at a higher frequency than elsewhere (Timmerman et al., 1997). As a consequence, physical injuries arising from these events can be expected to increase.

It is well-established that vulnerability to such health risks will vary according to factors such as availability of quality health care, the present health status of the population, and availability of technical and other resources (McMichael, 1993; WHO, 1996). Unfortunately, health care facilities and related infrastructure in many small island states and other developing countries often are inadequate. Hence, the resilience of such states and their capacity to respond effectively to (or mitigate) increasing health threats posed by climate change is likely to be low.

A range of adaptation strategies for reducing the severity of possible climate change-related health threats has been proposed, and many of these measures may be successfully pursued in the small island states. Such measures include, inter alia, implementation of effective health education programs, preventive maintenance and improvement of health care facilities, cost-effective sewerage and solid waste management practices, and disaster preparedness plans (McMichael, 1996).

Adoption of efficient early warning systems also would be beneficial in vulnerable small islands (Stern and Easterling, 1999). This process would involve monitoring of health-risk indicators by improving the forecasting of conditions that are favorable to the outbreak of climate-sensitive diseases such as dengue, cholera, and malaria (Patz et al., 1996; IPCC, 1998; Epstein, 1999). Where large populations exist, as in urban areas, simple, low-cost measures could be implemented to control the vectors of dengue and other diseases, where a risk of transmission exists. At the individual level, insecticide-treated bed nets could provide protection against vectors of malaria and filariasis. Simple technology, such as the use of sari cloth to filter drinking water, reduces the risk of cholera transmission at the household level. Although some measures for adapting to climate change can be deferred, early implementation of preventive strategies could reduce current and future health "costs."

Climate change could have direct and indirect impacts on other economic and social sectors in some small islands. The insurance industry is one sector that is highly sensitive to the magnitude and frequency of various hazards, including climate-related phenomena such as tropical storms and floods. Because insurance premiums are based on assessment of risk of occurrence of a particular event, any indication of an increase in the frequency or intensity of phenomena such as tropical cyclones and floods is likely to trigger an increase in the cost of insurance. Within the past decade, insurance costs in the Caribbean have increased significantly, following the passage of a series of severe hurricanes that caused widespread socioeconomic dislocation, injury, and loss of life. Claims were so high that some reinsurance companies withdrew from the market; others imposed higher deductibles, separate conditions for windstorms, and a premium structure to minimize the risk of underinsurance (Murray, 1993; Saunders, 1993). Even in cases in which these systems did not make landfall in the insular Caribbean itself—as with Hurricane Andrew, which devastated southern Florida in the United States—an increase in insurance premiums in the islands subsequently occurred.

Certain traditional island assets (goods and services) also will be at risk from climate change and sea-level rise. These assets include subsistence and traditional technologies (skills and knowledge), community structure, and coastal villages and settlements. Sea-level rise and climate changes, coupled with environmental changes, have destroyed some very important and unique cultural and spiritual sites, coastal protected areas, and traditional heritage sites in the Federated States of Micronesia, Tuvalu, the Marshall Islands, Niue, and Kiribati and continue to threaten others (Kaluwin and Smith, 1997).

Although some of these assets fall into the category of nonmarket goods and services, they are still considered to be of vital importance in small island states. In Tuvalu, for instance (as in other Pacific atoll states), strong traditional ties to land and sea constitute a vital component of local cosmology (Sem et al., 1996). Some of these values and traditions are compatible with modern conservation and environmental practices; therefore, priority action is needed in the following areas: research into traditional knowledge and practices of conservation and environment control—which have sustained these societies for generations, even in the face of hazards, risk, and uncertainty; inventorying of traditional, heritage, and other cultural sites; encouragement of practices that marry use of modern science and technology with traditional wisdom; and more effective transmission of traditional knowledge to younger generations.

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