.ON APRIL 2ND a device being similar to a snowfall device on the deck of the USS Hornet, an obsolete aircraft-carrier anchored in San Francisco Gulf, started generating a moisture of salted aerosol bits. The scientific collaboration behind the venture, the Marine Cloud Brightening (MCB) program, led due to the Educational institution of Washington, is actually looking into whether such aerosols may help to decrease weather change via a type of "geoengineering". What does this term way-- and why is it thus debatable?