It is estimated that there are on Earth more than 20 million cubic kilometers of ice. If the whole mass melted, scientists estimate that sea levels would rise nearly 66 meters above the current flooding almost every coastal city we know today.
If we continue increasing the level of CO2 in the atmosphere at the current rate, it is estimated that the Earth‘s ice could disappear by the rise in the average temperature of the planet from the current 26 to 14 degrees Celsius This could happen by the sum of factors such as the albedo effect, ocean currents and the release of huge deposits of methane gas hydrates submarine in the Arctic Ocean.
On a map, the result could not be more apocalyptic. You can see here the maps full of National Geographic, or under some of the places they disappear forever.