.ON APRIL 2ND a gizmo being similar to a snow equipment on the deck of the USS Hornet, an invalid aircraft-carrier moored in San Francisco Bay, started making a moisture of salted aerosol particles. The medical cooperation responsible for the venture, the Marine Cloud Brightening (MCB) program, led by the University of Washington, is exploring whether such sprays might help to slow environment improvement through a type of "geoengineering". What does this phrase mean-- as well as why is it so questionable?