.ON APRIL 2ND a gizmo being similar to a snowfall device on the deck of the USS Hornet, an invalid aircraft-carrier anchored in San Francisco Bay, started creating a mist of salty spray fragments. The clinical collaboration responsible for the project, the Marine Cloud Brightening (MCB) program, led due to the University of Washington, is checking out whether such aerosols may aid to reduce temperature modification with a kind of “geoengineering”. What does this phrase way– and why is it thus questionable?