Why should it matter to sea levels if ice shelves from the Antarctica break away from the main land, through climate change ?
It is true that floating ice does not change sea levels when it melts, just as a glass of water will not over flow when the ice cubes in it melts. The concern is that these collapses could be the beginning of the break up of other ice shelves, which would allow increased glacial discharge into the sea from the main land. If for example the West Antarctic ice shelf were to break away, which is considered unlikely this century, scientists estimate this alone could raise the sea level by up to 20 ft.
