.ON APRIL 2ND a contraption being similar to a snow device on the deck of the USS Hornet, a nonexistent aircraft-carrier anchored in San Francisco Bay, began producing a haze of salty aerosol fragments. The medical partnership behind the job, the Marine Cloud Brightening (MCB) programme, led by the Educational institution of Washington, is examining whether such sprays could help to slow environment improvement by means of a type of "geoengineering". What does this term method-- as well as why is it thus questionable?