.ON APRIL 2ND a gizmo being similar to a snow machine on the deck of the USS Hornet, an inoperative aircraft-carrier moored in San Francisco Gulf, began producing a mist of salty aerosol particles. The medical partnership responsible for the venture, the Marine Cloud Whitening (MCB) program, led due to the Educational institution of Washington, is actually exploring whether such sprays may assist to slow temperature modification by means of a type of "geoengineering". What does this term way-- and also why is it so questionable?