Humans have built about 500 islands out of the sea in recent decades. If ports, marinas, breakwaters, oil platforms, breakwaters and wind farms are added to that, human construction already affects 0.5% of the oceans. The percentage does not seem impressive but the cement is mostly concentrated on the narrow coastlines. China, with its miles and miles of fish farms, is leading an advance of land at the expense of water that will multiply in the next decade.
