Miami was built in a swamp. The only Pacific islands sinking are those where they have drained the aquifer under the island due to population growth, and are now sinking into it. For the sea level to rise, Antarctica and/or Greenland ice-caps need to melt: that will take tens of thousands of years.

I think you believed Al Gore’s science fiction mocumentary: large chunks of it are lies.

http://www.telegraph.co.uk/news/earth/earthnews/3310137/Al-Gores-nine-Inconvenient-Untruths.html