The "cloud ships" are favoured among a series of schemes aimed at altering the climate which have been weighed up by a leading think-tank. The project, which is being worked on by rival US and UK scientists, would see 1,900 wind-powered ships ply the oceans sucking up seawater and spraying minuscule droplets of it out through tall funnels to create large white clouds. These clouds, it is predicted, would reflect around one or two per cent of the sunlight that would otherwise warm the ocean, thereby cancelling out the greenhouse effect caused by Carbon Dioxide emissions. The unmanned ships would...