.ON APRIL 2ND a gizmo appearing like a snowfall device on the deck of the USS Hornet, a defunct aircraft-carrier tied in San Francisco Gulf, began creating a moisture of salty spray fragments. The scientific partnership responsible for the job, the Marine Cloud Whitening (MCB) program, led due to the College of Washington, is actually checking out whether such sprays might help to slow environment modification with a type of "geoengineering". What does this term mean-- as well as why is it thus disputable?