.ON APRIL 2ND a gizmo resembling a snow device on the deck of the USS Hornet, an inoperative aircraft-carrier anchored in San Francisco Gulf, began generating a moisture of salted aerosol fragments. The medical cooperation behind the venture, the Marine Cloud Brightening (MCB) program, led by the College of Washington, is looking into whether such aerosols might aid to decrease weather modification with a form of "geoengineering". What performs this phrase way-- as well as why is it thus controversial?