That is considerably more than earlier estimates by the United Nations panel of climate experts (which in turn has been accused of exaggerating figures, and has admitted mistakes, in the constant controversies over climate change).
The Danish researchers have used other methods to come to their findings. A quick and sharp reduction of CO2-emissions is the only way to limit the rise of sea levels, according to the researchers.
Copenhagen (left) is one city that could be affected by a sharp rise in sea levels. Larger coastal cities in Asia could fare much worse, and the island nation of the Maldives is under threat of disappearing under rising sea waters.
An OECD-report (Competitive Cities and Climate Change) from 2008 gives examples of how U.S. coastal states could be affected by higher sea levels. A 0.3 sea level rise would erode approximately 15 to 30 meters of shoreline in New Jersey and Maryland, 30 to 60 meters in South Carolina and 60 to 120 meters in California.
In popular waterfront developments around the world, measures are taken avoid damage by floods. In the HafenCity development in Hamburg, for instance, bottom floors of residential buildings are occupied by garages.
But rising sea levels cause all kinds of concerns. In Stockholm, another example, there are fears that the important underground station in the Old Town could be flooded.
The Thames Barrier protects London from floods.