How high will sea levels rise? Previous estimates that seemed far off or alarmistic are becoming reality. Today’s coastlines will look much different in 2100 and marine biologists are worried about the fate of Greenland and the Antarctic. In the analysis of the global impact of rising sea levels, research has extended its scope to inform governments on measures that may become necessary. For example, when will coastal areas have to be evacuated because the cost of protecting them is above their value? Great Britain is already seeing the effects.