Cloud Reflectivity Modification - Proposed Schemes - Seawater Spray

Seawater Spray

Various schemes have been suggested, such as that proposed by John Latham and Stephen Salter, which works by spraying seawater in the atmosphere to increase the reflectiveness of clouds. The extra condensation nuclei created by the spray will change the size distribution of the drops in existing clouds to make them whiter. The sprayers would use a fleet of around 1500 unmanned Rotor ships known as Flettner vessels to spray mist created from seawater into the air to thicken clouds and thus reflect more radiation from the Earth. The whitening is achieved as a result of the Twomey effect. In order to significantly cool the earth, the vessels have to spray sea water droplets at a rate of 50 cubic meter per second over a large portion of the Earth's ocean surface.

This technique can give >3.7 W/m2 of globally averaged negative forcing, which is sufficient to reverse the warming effect of a doubling of CO2.