The islands differ geomorphologically, from atolls with small, low islets and extensive lagoons, to raised limestone islands, to volcanic high islands with substantial topographic and internal climatic diversity (microclimates). They differ climatically as well, from wet western equatorial islands to seasonal tradewind environments [3]. Pacific Island landscapes and biodiversity are many and varied. Forested areas are still common in upland areas of high islands such as Hawai‘i, American Samoa, Pohnpei, and Kosrae. Mangrove forests fringe some islands, and form the breeding grounds for many valuable fish species and other marine life. Rich lagoons interlace other islands. Throughout the region, coral reefs are abundant and productive. In addition to hosting a wealth of marine life, the reefs also provide a natural form of coastal protection against storm wave and wind damage. Terrestrial resources of small-island states are generally limited. Oceanic islands have lower overall levels of biological diversity. Island species are much more likely to be endemic (found only on a single island or archipelago) and more susceptible to disruption by biological invasions and species loss [3].

Nukuoro Atoll, Source: NASA 2006. Nukuoro Atoll, one of 607 islands that make up the Federated States of Micronesia, is located just north of the equator. About 900 people live on the atoll whose lagoon is 6 kilometers in diameter. Forty-two patches of vegetation are located on the northeast and east portions of the atoll that face the dominant Easterly winds. The image shows the larger fields and settlement on the inland side of the largest forest patch protected from the wind. The land surface is probably slightly higher above sea level here because dunes build up preferentially on wind-facing slopes where beach sand is mobilized by wind. Swells driven by these winds can be seen approaching from the east-southeast (right) and wrapping around the atoll to produce an interference pattern on the downwind side.

The Pacific Islands are the home of an estimated 9,155,070 people in 2006 [2]. Approximately 1.7 million people live in the US Pacific Islands, with more than 70% located in Hawai‘i. Subsistence and commercial fisheries, tourism, and subsistence and semi-subsistence agriculture contribute greatly to Pacific island economies[3].

Bure, a traditional Fijian house. Source: Supin Wongbusarakum

Traditionally the Pacific Islands have close cultural, economic, and spiritual relationships with the land and sea. Clans and lineages in local social organizations and chiefly systems persist in many islands. They have retained an especially influential role in planning and decision-making in the RMI, many islands in the FSM, and American Samoa. To be effective environmental management in the islands relies on collaboration among various government and traditional decision-making authorities, each of which brings something unique to the process. Local and national decision-making and planning organizations are augmented by grassroots, regional, and international organizations. These organizations and institutional arrangements, if constructively engaged, can enhance the adaptive capacity and reduce the sensitivity of island coastal communities to climate change and variability [3].

A jewel-like Pacific atoll in Yap. Source: Ben Mieremet, NOAA Photo Library

Throughout the Pacific, islands vary greatly in geological, physical, and climatic features. The level of exposure and sensitivity to cyclones and to ENSO-related climatic variability is different from place to place. Nevertheless, characteristics such as limited land size, proneness to natural hazards, and external shocks enhance the vulnerability of islands to climate variability and change.

In most cases, small islands have low adaptive capacity, and adaptation costs are high relative to gross domestic product (GDP) [4]. According to the fourth assessment of the International Panel of Climate Change (IPCC), the potential impacts of climate change and variability were presented as follows [4]:

• Sea-level rise is expected to exacerbate inundation, storm surge, erosion and other coastal hazards, thus reducing the island size, threatening vital infrastructure, settlements and facilities that support the livelihood of island communities.

• Limited water resources in small islands are especially vulnerable to future changes and distribution of rainfall and are likely to be seriously compromised.

• Increasing sea surface temperature, rising sea level, and growing ocean acidity are very likely to affect the health of coral reefs and other near shore, marine and coastal ecosystems. These impacts exacerbate non-climate change stresses on the systems.

• Changes in the occurrence and intensity of El Niño-Southern Oscillation (ENSO) events are likely to have severe impacts on commercial and artisanal fisheries. Forests on many small islands can easily be decimated by violent cyclones or storms while increases in extreme events affect the adaptation responses of the slow-regenerating forests.

• Sea-level rise, inundation, seawater intrusion into freshwater lenses, soil salinization, and decline in water supply are very likely to adversely impact coastal agriculture. Away from the coast, changes in extremes (e.g., flooding and drought) are likely to have a negative effect on agricultural production.

• Effects of climate change on tourism are likely to be direct and indirect, and largely negative. Sea-level rise and increased sea water temperature will cause accelerated beach erosion, degradation of coral reefs, and bleaching. In addition, a loss of cultural heritage from inundation and flooding reduces the amenity value for coastal users. Water shortages and increased incidence of vector-borne diseases may also deter tourists.

• There is growing concern that global climate change is likely to impact human health, mostly in adverse ways. Increasing incidence of diseases has been observed. Examples include malaria, dengue, filariasis, schistosomiasis, and food- and water-borne diseases.

Children in Papua New Guinea.

The Pacific Island Countries have worked through regional organizations to address climate-related hazard risks and to initiate climate change adaptation programs (see organizations and programs in the Related Links). The islands have conducted assessments, developed observing and monitoring systems, developed risk reduction plans, and have prepared or are in the process of preparing National Adaptation Programmes of Action (NAPA) through the United Nations Framework Convention on Climate Change (UNFCCC) (see Samoa’s NAPA and Tuvalu’s NAPA). These plans enable access to funding to initiate adaptation measures. As a result of the Climate Variability and Change Workshops in the US Pacific Islands, several islands formed task forces to assess their risks and begin developing adaptation plans, similar to the plans promoted by SPREP’s Climate Programme that focus on developing awareness and support at policy levels and within local communities using participatory approaches for project implementation (see Stakeholder Dialogue, presentations by Taito Nakalevu).