.ON APRIL 2ND a contraption being similar to a snowfall maker on the deck of the USS Hornet, a nonexistent aircraft-carrier anchored in San Francisco Bay, started making a moisture of salty aerosol bits. The scientific collaboration behind the task, the Marine Cloud Brightening (MCB) program, led due to the Educational institution of Washington, is actually looking into whether such aerosols may help to reduce weather adjustment with a kind of "geoengineering". What does this condition method-- and why is it so disputable?