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CLIMATE CHANGE AND COASTAL VULNERABILITY IN SMALL ISLAND STATES

CLIMATE CHANGE AND COASTAL VULNERABILITY IN SMALL ISLAND STATES. Leonard A. Nurse IPCC Coordinating Lead Author AOSIS Inter-Regional Preparatory Meeting for WSSD, January 7 - 11, 2002. BACKGROUND AND CONTEXT. Consensus of Marine and Coastal Scientists

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CLIMATE CHANGE AND COASTAL VULNERABILITY IN SMALL ISLAND STATES

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  1. CLIMATE CHANGE AND COASTAL VULNERABILITY IN SMALL ISLAND STATES Leonard A. Nurse IPCC Coordinating Lead Author AOSIS Inter-Regional Preparatory Meeting for WSSD, January 7 - 11, 2002

  2. BACKGROUND AND CONTEXT Consensus of Marine and Coastal Scientists “Global climate change will affect the physical, biological and biogeochemical characteristics of the oceans and coasts, modifying their ecological structure, their functions, and the goods and services they provide” (IPCC-TAR, p. 345, Chapter 6, Coastal Zones and Marine Ecosystems”). • In the case of small islands, coastal vulnerability to climate change will be enhanced as a consequence of: Sea-level rise Accelerated erosion Increased risk of storm flooding and inundation Elevated sea-surface temperatures

  3. COASTAL VULNERABILITY: CONSEQUENCES FOR SMALL ISLAND STATES Sea-LevelRise: • Although there are regional variations in the signal, sea level in the regions of the Small Island States is expected to rise by as much as 5mm yr-1, for next 100 yrs, as a result of GHG-induced global warming. Some of the consequences will be:  Coastal Land loss, especially on atolls (Pacific and Indian Oceans) and low limestone islands (Caribbean).E.g. on Majuro Atoll (Marshal Islands), 65 ha (80% dry land) would be lost. In extreme cases, abandonment of some atolls and small islands may be the only practical option, given (i) elevation a.m.s.l., and (ii) physical size. E.g. Maldives, Indian Ocean. Loss of coastal infrastructure. Practically all critical infrastructure is located at or near the coast on islands.

  4. COASTAL VULNERABILITY: CONSEQUENCES FOR SMALL ISLAND STATES (cont’d) BeachErosion • Model runs and observed data consistently project that accelerated beach erosion will be an inevitable threat facing small islands. While much present-day erosion is man-induced (sand mining, construction in active beach zone, infringement of building set-backs, etc.), empirical studies show that SLR is a significant contributory factor. Higher Water Levels + Higher Wave Amplitude = Increased Wave Energy  (a) In Trinidad, some beaches are retreating by as much as 2.0 m yr-1, where sea level has been rising at rate of 8-10 mm yr-1, during the past 15 years. (b) In Fiji, where sea level has risen by 1.0-1.5 mm yr-1, beaches at Viti Levu and Taveuni have retreated by some 30.0 m since 1960.

  5. CONSEQUENCES OF CLIMATE CHANGE FOR SMALL ISLAND STATES (cont’d) StormSurge,FloodRisksandInundation: • Although there is uncertainty about the future behaviour of tropical cyclones (hurricanes), flood risks and inundation from storm surge will be more severe. Even quantitatively small increases in relative sea level will have a disproportionate effect on flood levels (Non-linear relationship between SLR and inundation levels). Flood risk modeling (HADCM2, HADCM3, UKMO, 1999) suggests that by 2080, numbers facing severe floods in the Caribbean, Indian and Pacific Ocean regions would be 200 times higher than if there were no SLR. Recent studies in Cuba (Perez et al. 1999, based on HADCM2), identified 98 coastal settlements with a total population exceeding 50 000 persons, which would be completely inundated by a 1.0 m rise in sea-level.

  6. CONSEQUENCES OF CLIMATE CHANGE FOR SMALL ISLAND STATES (cont’d) Coralreefs: • Observational evidence shows that periodic warming of the ocean surface, as occurs in El Nino years, leads to coral bleaching. The major events of the past 20 years occurred at times when ocean temperatures have been about 10 C higher than the summer maximum. Most intense episode on record occurred during 1997-98 El Nino. On some islands >90% of live reefs affected. Increasing atmospheric CO2 is being accompanied by similar increases in the oceans. This is expected to lead to a reduction in the rate of calcification of reef -building corals by between 14-30% by 2050.

  7. CONSEQUENCES OF CLIMATE CHANGE FOR SMALL ISLAND STATES (cont’d) Tourism is a major revenue earner and generates significant employment. In addition the industry is almost entirely ‘coastal’. The impact of climate change on this sector will be both direct and indirect. • SLR will disrupt the sector through loss of beaches, the threat to physical plant and vital infrastructure. • The industry is also sensitive to other climate-related impacts, e.g. the loss of corals and other marine flora and fauna, which support the scuba diving industry. • The highest temperature changes are occurring in the middle- and high-latitudes. A large % of tourism is generated by the desire of visitors to ‘escape’ the cold winters of the North. Milder winter temperatures in these markets could reduce the appeal of islands as tourist destinations.

  8. COASTAL VULNERABILITY REDUCTION IN SIDS: GUIDING PRINCIPLES AND ACTIONS GuidingPrinciples • While we need financial and technical assistance to help us reduce our vulnerability to climate change, the response and overall strategy must be largely designed and implemented by SIDS. • In designing our response and adaptation strategies we should seek, wherever possible, to draw on the experiences, expertise and relevant skills of SIDS and other appropriate developing countries (Promotion of South-South cooperation). • We must also draw on indigenous skills and traditional knowledge that have helped to sustain many communities in the past.

  9. COASTAL VULNERABILITY REDUCTION IN SIDS: GUIDING PRINCIPLES AND ACTIONS (cont’d) BASICREQUIREMENTS Inventory of Coastal Resources and Uses • Define the nature of these resources (what are they: Coral reefs? Seagrasses? Offshore sand reserves ? Minerals?) • Location/ spatial distribution (Where are these resources?) • Quantification of resources (How much?) • Present status/trends: Are the beaches eroding or accreting? Are fish stocks dwindling or expanding?

  10. COASTAL VULNERABILITY REDUCTION IN SIDS: GUIDING PRINCIPLES AND ACTIONS (cont’d) We Need Tools for Reducing Coastal Vulnerability: • Training in key areas of marine and coastal science e.g. oceanography, marine biology, fisheries biology, marine geology, coastal geomorphology (Capacity Building). • Data collection and scientific research at the regional and local scales. For example, few SIDS have geodetic-controlled tide gauges or continuously recording marine meteorological stations (Research and Systematic Observation: UNFCCC Article 5). • Downscaling of GCMs to finer resolution (e.g. 50 km, 25 km), to better facilitate meaningful vulnerability assessment at the island scale (Capacity building and Transfer of technology).

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