.ON APRIL 2ND a gizmo looking like a snowfall maker on the deck of the USS Hornet, an obsolete aircraft-carrier moored in San Francisco Bay, started generating a mist of salty spray particles. The clinical collaboration responsible for the task, the Marine Cloud Brightening (MCB) program, led due to the University of Washington, is actually looking into whether such aerosols may assist to decrease climate adjustment via a kind of "geoengineering". What does this condition way-- and also why is it thus debatable?