Population growth, urbanization and rising sea levels are building enormous vulnerability to flooding in Malé, a tiny island that is the capital of the Indian Ocean nation of Maldives. (Click for &lt;a href=&quot;//ngm.nationalgeographic.com/2013/09/rising-seas/steinmetz-photography#/08-maale-maldives-670.jpg&quot;&gt;larger version and National Geographic article&lt;/a&gt;.)