Rising sea levels due to climate change this century could have dangerous consequences for the tropical islands of the Pacific Ocean and the western Indian Ocean, as well as for Asian megacities. This was the conclusion reached by scientists from the French National Center for Scientific Research (CNRS) and the University of La Rochelle in France, who published an article in the journal Nature Climate Change.

Climate change from anthropogenic emissions of greenhouse gases includes not only global warming but also changes in climate cycles such as natural fluctuations in sea surface temperature called the Southern Oscillation (its opposite phases are called El Niño and La Niña). The scientists used a computer model to calculate how changes in natural fluctuations (or internal variability) might contribute to sea level rise in certain coastlines.

The Southern Oscillation has been found to contribute 20 to 30 percent to sea level rise in addition to the direct effects of global warming. For example, it is estimated that Manila will experience 18 times more coastal flooding by 2100 than in 2006 due to climate change alone. But in the worst case, they can occur 96 times more often due to the combination of global warming and the Southern Oscillation.

Inland climate variability will also lead to sea level rise along the west coast of the United States and Australia. Sea level rise will vary by region, as shifts in ocean currents will likely divert more water to certain coastlines, including the northeastern United States. Source