The climate of the Pacific Island region is influenced by a variety of factors, including trade wind regimes and movement of the South Pacific Convergence Zone (SPCZ), as well as the El Niño-Southern Oscillation (ENSO) and the Interdecadal Pacific Oscillation (Mimura et al., 2007). Due to these natural processes, the region is prone to considerable climate variability and weather-related disasters—including tropical cyclones, floods, coral bleaching and storm surges (World Bank, 2009). Within the context of this natural variability, observed, averaged South Pacific Ocean surface and island air temperatures (southwest of the SPCZ) have risen by between 0.6o and 1.0oC since 1910. Other observed changes in the Pacific region include increases in: the number of Category 4 and 5 storms in the southwest Pacific; tropical cyclone activity (east of 160oE), particularly in association with El Niño events; and a rise in Pacific basin sea levels at a rate of 0.77 millimeters per year (Mimura et al., 2007, and citations therein).
Projections of future changes in Pacific climatic conditions are uncertain due to the limited availability of historical data, weaknesses in existing modeling capabilities and an incomplete understanding of current climate focuses, such as ENSO. Within these limitations, studies anticipate that the Pacific region will experience warming of approximately 0.8o to 1.8°C by mid-century, reaching 1o to 3.1°C by the end of the century. Precipitation projections for the region are less certain; as too are projections regarding changes the characteristics of tropical cyclones and ENSO patterns. Sea level rise, projected to be 0.19 to 0.58 meters over the course of this century (2080 to 2099; Meehl et al., 2007), is of particular concern to the low-lying coral atoll countries of Kiribati, the Marshall Islands and Tuvalu (Barnett, 2001).
These projected and potential changes in the Pacific climate have raised concerns regarding potential impacts on the region’s coastal and marine resources, water resources, agricultural resources, human health, and forests. The possible impacts of projected and potential climatic changes on these sectors include:
- Coastal and marine resources: higher sea temperatures, rising sea levels and the potential for stronger storms could lead to the bleaching of corals, loss of wetlands, flooding of low-lying regions, erosion of coastlines, endangerment of mangroves, changes in fish circulation patterns, and damage to infrastructure—nearly all of which is located in coastal locations (FAO, 2008; Mimura et al., 2007; PNGMEC, 2000; SIMCTA, 2004; SMNREM, 2005).
- Water resources: higher temperatures, changes in precipitation patterns, salt water intrusion and existing challenges such as deforestation could compromise the availability and quality of water resources—an issue of particular importance for those Pacific Island states that have existing water scarcity concerns due to their size, geology and topography (Mimura et al., 2007; SMNREM, 2005; SIMCTA, 2004).
- Agricultural resources: approximately 70 per cent of the crops grown in the Pacific are dependent upon seasonal summer rains (FAO, 2008). Changes in the patterns of these rains, along with soil salinization, altered pest and disease patterns, and potentially higher risk of extreme weather events could reduce agricultural output and, by extension, negatively impact national economies.
- Human health: rising temperatures, more variable rainfall, and potentially more intense extreme weather events could result in greater incidence of vector- and water-borne diseases such as malaria, dengue fever and diarrhea (Mimura et al., 2007). Health may also be impacted by compromised food security, severe storms, drought and declines in water quality and quantity (PNGMEC, 2000).
- Forestry, biodiversity and nature: climate change could augment existing concerns related to deforestation and loss of biodiversity by leading to accelerated beach erosion, degradation and bleaching of coral reefs (Mimura et al., 2007) and changes in the growing conditions suitable for established ecosystems.
Identified adaptation needs and priorities
In light of these projected climatic changes and understood vulnerabilities, Pacific Island countries have identified a number of adaptation actors to reduce the vulnerability of particular sectors to the impacts of climate change. These adaptation actions include (CIES, 1999; FMFNP, 2005; KMELAD, 2007; MIEPA, 2000; PNGMEC, 2000; SIMCTA, 2004; SMNREM, 2005; TDE, 2005; VMIPU, 2007):
- Coastal and marine resources: land-use policies that encourage settlement away from low-lying areas; mangrove and reef protection measures; improved public awareness; establishment of early-warning systems; and marine breeding and restocking programs.
- Water resources: improved water catchment management; soil conservation measures; rainwater collection and desalinization; and water conservation programs, including demand management and leakage control.
- Agricultural resources: research into flexible farming options, salt-resistant crops and heat-tolerant species; cessation of crop production on marginal and sloping lands; agroforestry techniques; pest and disease management; and crop diversification.
- Human health: prevention and preparedness for epidemics; improved water safety and sanitation; malaria awareness programs; and improved medical services.
- Forestry, biodiversity and nature: enhanced research into the possible impacts of climate change on flora and fauna as well as ecosystem rejuvenation; reforestation and conservation programs; promotion of agroforestry; changes in land use policies; and generation of public awareness.
Source: Review of Current and Planned Adaptation Action: The Pacific. Contributing Authors: Rosemary Dohan, Hilary Hove, Daniella Echeverría, Anne Hammill, Jo-Ellen Parry (International Institute for Sustainable Development), 2011.