.ON APRIL 2ND a gizmo resembling a snowfall maker on the deck of the USS Hornet, an obsolete aircraft-carrier anchored in San Francisco Bay, began generating a haze of salted spray bits. The scientific partnership responsible for the project, the Marine Cloud Brightening (MCB) program, led due to the Educational institution of Washington, is actually examining whether such aerosols may help to reduce climate improvement through a kind of "geoengineering". What performs this condition way-- and why is it therefore debatable?