How much does sea level rise if all the worlds ice melts?
To a first approximation, if all the floating sea ice in the world melted, there would be no change in sea level at all, as the floating ice will have displaced its own weight of water. However, if land ice melts, that will raise sea level. All the world’s glaciers and small ice caps contain approximately 0.5 m of sea level equivalent between them, while the great Greenland and Antarctic ice sheets contain approximately 7 and 61 m respectively. Consequently, if all the wolrd’s ice melted in a very much warmer world, sea level would be approximately 70 m higher. However, when land ice melts the distribution of the mass of water around the global ocean is by no means uniform. A large melting would result in a modification in the Earth’s gravity field which would result in the sea level change being higher in some places than in others.
