60% of the population is below sea level, even. It's true that only 25% of the land area is below sea level (and another 25% less than 1 meter above it), but that happens to be the most densely populated area.
For example, if the sea were to spill over onto all below-sea-level land, Amsterdam would be an island, some 15 km off the new coastline. The Port of Rotterdam would still be there (25km offshore), but the rest of the city would disappear.
For example, if the sea were to spill over onto all below-sea-level land, Amsterdam would be an island, some 15 km off the new coastline. The Port of Rotterdam would still be there (25km offshore), but the rest of the city would disappear.