In Next Decades, Frequency of Coastal Flooding Will Double Globally

The frequency and severity of coastal flooding throughout the world will increase rapidly and eventually double in frequency over the coming decades even with only moderate amounts of sea level rise, according to a new study released today in “Nature Scientific Reports.”

This increase in flooding will be greatest and most damaging in tropical regions, impairing the economies of coastal cities and the habitability of low-lying Pacific island nations. Many of the world's largest populated low-lying deltas (such as the Ganges, Indus, Yangtze, Mekong and Irrawaddy Rivers), also fall in or near this affected tropical region.

The new report from scientists at the U.S. Geological Survey, the University of Illinois at Chicago and the University of Hawaii shows that with just 10 to 20 cm (4 to 8 inches) of sea level rise expected no later than 2050, coastal flooding will more than double. This dramatic increase in coastal flooding results from rising sea levels combined with storm-driven flooding, including the effects of waves and storm surge.

In most coastal regions, the amount of sea level rise occurring over years to decades is small, yet even gradual sea level rise can rapidly increase the frequency and severity of coastal flooding. Until now, global-scale estimates of increased coastal flooding due to sea level rise have not considered elevated water levels due to waves, and thus have underestimated the potential impact.

Continue reading at USGS.

Photo via USGS.