If all of the ice in the polar regions melted, cities such as New York City, Philadelphia, New Orleans, Miami, Houston, Rio, Copenhagen, Amsterdam, Mumbai, Singapore, Hong Kong, and Tokyo would be completely inundated. This would be a catastrophe for the ecosystem on a scale that has never been seen before.These cities are all located on coasts, making them susceptible to the threat posed by increasing sea levels. If all of the ice in the polar regions were to melt at once, the ocean would rise by more than 60 metres. These cities, along with a great number of others located all over the world, would be submerged as a result.The aftermath of such a catastrophe would be devastating on a global scale. There would be an inconceivable amount of economic devastation, as well as the displacement of millions of people. The results of this would be catastrophic for the natural world.This is not a prediction of the future; rather, it is a possibility that is very likely to occur. The polar ice caps are melting at an alarming rate, and the implications will be catastrophic if something is not done to stop this process.