"When the Arctic Ocean ice melts, it never raises sea level because floating ice is floating ice, because it's displacing water," O'Brien said. "When the ice melts, sea level actually goes down.

"I call it a fourth grade science experiment. Take a glass, put some ice in it. Put water in it. Mark level where water is. Let it met. After the ice melts, the sea level didn't go up in your glass of water. It's called the Archimedes Principle."