Just last month, the U.S. National Oceanic and Atmospheric Administration declared only the third recorded global coral bleaching event. If the frequency of these events increases due to rising ocean temperatures, there is little doubt that these islands will be swallowed by the sea.
At current rates, sea-level rise will either submerge or make unlivable a host of islands within a century, maybe sooner.
Source: Melting ice a ticking time bomb for Pacific islands | Human Nature – Conservation International Blog