20 countries most at risk from sea level rise.

Every global shore touches the same ocean, and the ocean is rising.

Climate Central just completed a novel analysis of worldwide exposure to sea level rise and coastal flooding. We found that 147 to 216 million people live on land that will be below sea level or regular flood levels by the end of the century, assuming emissions of heat-trapping gases continue on their current trend.

By far the largest group — 41 to 63 million — lives in China. The ranges depend on the ultimate sensitivity of sea level to warming.

But even these figures may be two to three times too low, meaning as many as 650 million people may be threatened.

Our analysis relied on global data on elevation and population, but our experience using similar data in the U.S. strongly suggests that this global data is not as accurate or precise as more modern data sources. 

Comparing results for U.S. vulnerability using global data and state-of-the-art domestic data, we found that global elevation data led to major underestimates compared to modern U.S. elevation data (by a factor of 3 to 4), whereas global population data led to overestimates by a factor of 1.6 to 1.8. The net effect of global data was underestimation by a factor of 2 to 3.

http://www.wunderground.com/news/20-countries-most-risk-sea-level-rise-20140924