.ON APRIL 2ND a gizmo being similar to a snow maker on the deck of the USS Hornet, an inoperative aircraft-carrier moored in San Francisco Bay, started making a haze of salty spray particles. The scientific partnership responsible for the job, the Marine Cloud Brightening (MCB) programme, led due to the University of Washington, is actually investigating whether such aerosols might help to decrease temperature improvement through a type of "geoengineering". What performs this condition way-- and also why is it therefore disputable?