Global warming causes the melt of polar ice. If the entire ice on greenland melts, the sea-level will rise up to 7 meters/23 feet. Many regions in the world will be affected, primarily asia,
worst of all Shanghai.
But other coast or river bank areas will also be flooded, such as in the UK, USA, Japan or the Netherlands. People will be able to move landwards. But their homes, entire cities and beautiful landmarks will be lost forever.