The world's coastal cities are some of the most beautiful, culturally vibrant and heavily populated urban areas. They are also some of the most popular places for summer vacations. However, rising sea levels threaten these areas.
The Earth's oceans rose by an average 7.7 inches (195 mm) between 1870 and 2004, according to a study in Geophysical Research Letters. Projections by the U.S. National Research Council warn that the seas could rise a further 22 to 79 inches (56 to 200 cm) during the 21st century.
Here are nine popular areas endangered by the encroaching ocean.
New Orleans faces a double threat from both land and sea.
The muddy foundation of the city is not firm enough to support the city. As New Orleans sinks into its feet of clay, the Gulf of Mexico is rising around it.
The disastrous flooding after Hurricane Katrina in 2005 put the Big Easy on defense mode, but even the best efforts may not be enough.
Much of New Orleans already lies 5 to 10 feet (1.5 to 3 meters) below sea level. A report from the U.S. Geological Survey warned that the ocean could rise 8 to 13 feet (2.5 to 4 meters) above the city by 2100.