.ON APRIL 2ND a device looking like a snow equipment on the deck of the USS Hornet, a nonexistent aircraft-carrier moored in San Francisco Bay, began producing a mist of salted aerosol bits. The scientific cooperation responsible for the venture, the Marine Cloud Whitening (MCB) program, led due to the College of Washington, is actually investigating whether such aerosols could help to decrease climate adjustment by means of a kind of "geoengineering". What does this condition method-- as well as why is it therefore controversial?