Ice cube theory... Thing is, the ice caps that will melt are above sea level, so it'll be the same as having water with ice cubes at the rim of the glass, but half the ice cube sticking out the top. Then when it melts, the water will flow over top of the glass... Like when you get in a bath, if you were to fill it up as you were sat up in it, and filled it to the top, when you lay down/go underwater, it'll spill over the edge. Isn't that kinda the same as the ice caps melting? and how the seas will rise...