.ON APRIL 2ND a contraption being similar to a snow equipment on the deck of the USS Hornet, a defunct aircraft-carrier tied in San Francisco Bay, began producing a haze of salty aerosol fragments. The scientific partnership responsible for the venture, the Marine Cloud Brightening (MCB) programme, led due to the College of Washington, is actually investigating whether such aerosols may aid to reduce environment change via a kind of “geoengineering”. What performs this term mean– as well as why is it so controversial?