It depends. For example, I heard on National Public Radio (in the United States) alarmistic reports that the coast of South Carolina is sinking, and the federal government needs to spend thick billions of dollars on protecting properties there. I went to see it myself. There are vast wetlands on the Atlantic shore, and even a mild sea-level rise can put them underwater. But it was known for at least half a century that this land is sinking. The time for emergency action was for them fifty years ago. But, I saw new buildings being built on the shores today. Charleston, SC, is planning to double the number of residents by 2050. I could not afford to buy a condo there, but I am asked for my taxes being used to protect these properties from the land sinking. I believe that some of these properties can be saved, but the rich people living there can pay for that themselves. Everybody else should plan to move to higher ground. It is worth noting that the south England shores sink similarly, but as the terrain is high over there, the loss of land is barely noticeable.

Besides a few instances as this one, climate warming will benefit most of the United States. Farmers in north states might add new crops. Greenland might be habitable again. I read reports that due to climate change Siberia is opening new opportunities for farming and human settling. There are plenty of places and opportunities for people affected by the loss of land in some areas.