The coast is kind of a favorites place. People love to visit, sit on the beach, and most of all, we really, really love to live there. But as much as humans like living near the ocean, we don't tend to like living in the ocean.
As the Earth gets warmer, melting ice caps and other forces could cause the average sea level to rise by as much as two meters by the year 2100. And to avoid living underwater, a lot of people might end up needing to move.