Animation of the Earth showing the effects on the landmasses of a sea level rise of 70 metres. The familiar outlines of the continents are drastically altered in this scenario. It has been calculated that the complete melting of the Greenland and Antarctica ice sheets would cause such a rise, with Greenland contributing some seven metres, and Antarctica more than 61m. Earth's sea level has fluctuated considerably even in the recent past: during the last glacial maximum some 20,000 years ago, so much water was stored as ice that sea levels were around 120 metres lower than today.