.ON APRIL 2ND a gizmo being similar to a snow maker on the deck of the USS Hornet, a defunct aircraft-carrier tied in San Francisco Gulf, started producing a moisture of salty aerosol particles. The medical cooperation behind the venture, the Marine Cloud Whitening (MCB) program, led by the College of Washington, is checking out whether such aerosols could help to decrease temperature change by means of a form of “geoengineering”. What performs this term mean– and also why is it so questionable?