The global warming that the world is beginning to experience will likely have a major impact on coastal and marine environments.

• The sea has an enormous capacity to store heat. Warmer water, combined with anticipated changes in ocean currents, could have a devastating impact on marine ecosystems and biodiversity.
• One potential result could be a reduction in the upwelling of nutrients, which would in turn reduce productivity in key fishing areas.
• Decreased growth may also be seen in coral reefs, with high concentrations of CO₂ in the water impairing the deposition of limestone required for coral skeletons (UNEP, 2002).

A significant sea level rise is one of the major anticipated consequences of climate change. This will cause some low-lying coastal areas to become completely submerged, while others will increasingly face short-lived high-water levels. These anticipated changes could have a major impact on the lives of coastal populations. The small island developing states (SIDS) will be especially vulnerable to the effects of sea level rise, and to changes in marine ecosystems, because of their major dependence on marine resources (UNEP, 2002).

The extent of future sea level rise will depend on a multitude of factors, and is therefore extremely difficult to predict. While rising sea levels will be exacerbated by thermal expansion of the warming oceans, and the melting of land ice, they will be partially offset by increased precipitation over Antarctica (Met Office UK, 2001).