The majority of the population lives near the coast, and this percentage is increasing. Those people (billions of them) will either be displaced, resulting in

The majority of the population lives near the coast, and this percentage is increasing. Those people (billions of them) will either be displaced, resulting in a huge humanitarian crisis, or spend enormous amounts of money and effort to create dykes and levies. Remember Hurricane Katrina's effect on New Orleans? If the world went the latter direction, such disasters would be a risk for every coastal city. And climate change will likely involve more frequent and intense storms...