Tropical Pacific islands may see more frequent swings in extreme sea levels, in addition to the gradual sea level rise that is an established impact of climate change. El Niño events are associated with a see-saw in sea levels, with higher sea levels shifting eastward and lower sea levels experienced in the western Pacific. This is followed six months to a year later by a north-south see-saw with levels dropping about 30 cm in the southern hemisphere. In the South Pacific Islands, these events expose shallow marine systems, causing coral die-offs and foul smelling tides. Researchers at the University of Hawai’i and the Commonwealth Scientific and Industrial Research Organisation used modelling and tide-gauge analysis to show that projected changes in the behaviour of El Niño patterns and the response of the Pacific wind will result in a doubling of extreme sea level occurrences. This will have adaptation implications for Pacific island communities.