‘Megayachts’ are environmentally indefensible. The world must ban them | Chris Armstrong

Roman Abramovich's yachts are said to emit more carbon than many small countries. This is unsustainable, and wrong

The rich gazed at their superyachts, and decided they were not enough. The new breed of megayachts, which are at least 70 metres (230ft) in length, may be the most expensive moveable assets ever created.

Roman Abramovich's custom-designed Eclipse is estimated to be worth upwards of $800m. When he tires of its swimming pool, submarine and armoured plating, he can use one of its helipads to fly to the $475m Solaris, which he also owns. On the way he might, perhaps, glimpse the $600m Azzam, commissioned by the former president of the United Arab Emirates.

Chris Armstrong is a professor of political theory at the University of Southampton in the UK and the author of A Blue New Deal: Why We Need a New Politics for the Ocean and the forthcoming Global Justice and the Biodiversity Crisis: Conservation in a World of Inequality