How scientists are creating a glimpse of the climate change future
3 November 2010 Last updated at 18:39 GMT
Every year the world loses thousands of hectares of land as rising sea levels engulf coastal areas.
By the end of this century the sea is expected to rise another 18 to 59cm, threatening heavily populated coastlines such as Bangladesh and entirely destroying other nations such as the Maldives.
Most of these projections are based on theory, as nobody knows exactly how the earth will react to climate change.
But in the world's longest-running carbon dioxide experiment in Maryland, scientists have created a unique salt marsh that simulates the environment of the future.
Jane O'Brien met senior scientist Pat Megonigal at the Smithsonian Environmental Research Center to discover what they have learned so far.