.ON APRIL 2ND a gizmo resembling a snowfall maker on the deck of the USS Hornet, an inoperative aircraft-carrier tied in San Francisco Bay, began creating a mist of salted aerosol fragments. The scientific collaboration responsible for the project, the Marine Cloud Brightening (MCB) program, led by the Educational institution of Washington, is exploring whether such aerosols may assist to reduce temperature change via a form of "geoengineering". What performs this term way-- as well as why is it thus debatable?