Sea levels may rise by about one meter by 2100 if carbon emissions continue unchecked, according to a recent survey of experts, and the effects on coastal cities could be devastating.

A 2008 report from the OECD ranked the most exposed cities, identifying areas that would be exposed if sea levels rose 0.5 meters by 2070 and there was a once-in-a-century storm, accounting for larger storms in some areas (raising water an additional 0.5 meters to 1.5 meters), natural and artificial land shifts, and urban growth.

Calcutta, India could be hit hardest, with 14 million people and $2.0 trillion in assets exposed in 2070 — and the problem could get even worse by 2100.

Risk can be partially mitigated on a local level by flood and wind protection as well as city planning. Globally, it requires efforts to reverse rising carbon dioxide emissions, which are increasing the Earth's temperature and causing water to expand and land ice to melt into the ocean.

We averaged population and asset exposure ranks to determine the cities with the most to lose. We then mapped areas of the cities that could be affected by a sea level rise of less than two meter using data and a tool from a University of Arizona study. Our findings are displayed below starting with the most exposed. It should be noted that all coastal cities are at risk, not just the ones on this list.























































