Ebbie-The North Pole has no land, only ice. The ice displaces enough water so that it is buoyant. I could calculate the exact percentage of ice aboce water to that below, but basically floating ice has little to no effect on the ocean's volume. The Antarctic ice sheets, on the other hand, are on land. If they were to melt. most of that water would enter the oceans, raising sea levels by (I believe) about 50 meters. While hardly the world-sea depicted by Waterworld, that would flood much of Florida and the Netherlands, and cut many coastlines deeply worldwide. It would also lead to increased temperatures around the world (ice reflects a staggering amount of sunlight into space), increasing the fertility of temperate and subarctic highlands throughout the world. While it would be a short-term disaster, the long-term effects are difficult to predict, given their dependence on weather patterns, which are utterly unpredictable.