Climate change in the Seychelles: implications for water and coral reefs

摘要

The Seychelles is a small island state in the western Indian Ocean that is vulnerable to the effects of climate change. This vulnerability led the Intergovernmental Panel on Climate Change (IPCC) in 2001 to express concern over the potential economic and social consequences that may be faced by small island states. Small island states should be prepared to adapt to such changes, especially in view of their dependence on natural resources, such as water and coral reefs, to meet basic human welfare needs. Analysis of long-term data for precipitation, air temperature, and sea-surface temperature indicated that changes are already observable in the Seychelles. The increase in dry spells that resulted in drought conditions in 1999 and the 1998 mass coral bleaching are indicative of the events that are likely to occur under future climate change. Pre-IPCC Third Assessment Report scenarios and the new SRES scenarios are compared for changes in precipitation and air surface temperature for the Seychelles. These intercomparisons indicate that the IS92 scenarios project a much warmer and wetter climate for the Seychelles than do the SRES scenarios. However, a wetter climate does not imply readily available water, but rather longer dry spells with more intense precipitation events. These observations will likely place enormous pressures on water-resources management in the Seychelles. Similarly, sea-surface temperature increases predicted by the HADCM3 model will likely trigger repeated coral-bleaching episodes, with possible coral extinctions within the Seychelles region by 2040. The cover of many coral reefs around the Seychelles have already changed, and the protection of coral-resilient areas is a critical adaptive option.