.ON APRIL 2ND a device looking like a snowfall equipment on the deck of the USS Hornet, an obsolete aircraft-carrier moored in San Francisco Bay, started making a moisture of salted spray fragments. The scientific cooperation responsible for the job, the Marine Cloud Whitening (MCB) program, led due to the Educational institution of Washington, is checking out whether such sprays may aid to reduce environment adjustment through a kind of "geoengineering". What does this condition mean-- as well as why is it therefore questionable?