If AGW is true and sea levels rise significantly a lot of people who currently live in densely populated coastal areas will have their property and economic opp

If AGW is true and sea levels rise significantly a lot of people who currently live in densely populated coastal areas will have their property and economic opportunities destroyed by no fault of their own. For example, Wikipedia says that Bangladesh has 156 million people as of 2013, and that "most parts of Bangladesh are less than 12 m (39.4 ft) above sea level, and it is estimated that about 10% of the land would be flooded if the sea level were to rise by 1 m (3.28 ft)". Do you think millions of people will be able to migrate elsewhere, a large share of them even to other countries, without causing a lot of social conflicts? Just imagine all of those people want to immigrate to your country. What is the government going to do about that?