The amount of sunlight hitting the earth is reduced if the surface is reflective, for example by snow, cloud or even the ‘white horses’ on the top of waves.. However, high cloud also acts as a blanket, preventing the surface from releasing infra-red radiation during the night. So the optimum solution is to generate low-level cloud which disappears at night.

The Cloud Machine is an ocean-going vessel, wave-powered, producing a low-level cloud by using high-efficiency ‘fogging’ nozzles, as developed by the fire-fighting industry.

The basic machine would be about 1000m long (bit bigger than an oil tanker) by say 80m wide… big enough to straddle large waves comfortably. It moves parallel with the wave-front, thus harvesting the maximum amount of energy. Trailing behind is a further 2km of ‘spray boom’; basically a pipe with masts and spray heads every 10m.

The entire machine, wave harvester plus boom, starts fogging at dawn and releases cloud which drifts downwind during the day, eventually shading some 500 square kilometers. By varying the droplet size, the cloud can be engineered to dissipate (drop back into the ocean) by nightfall, thus leaving the sky clear for maximum infrared radiation during the hours of darkness.

Satellite guidance will lead such machines to areas of high local sea temperature and moderate winds. The resulting shading could be expected to reduce local heating in tropical oceans by up to 70%.

Deployment of a modest fleet of such vessels could result in moderation of ocean surface temperatures, particularly in hurricane-breeding zones.

Each machine achieves an effective heat reduction equivalent to the output of 16 central power stations.