.ON APRIL 2ND a gizmo being similar to a snowfall equipment on the deck of the USS Hornet, a nonexistent aircraft-carrier moored in San Francisco Bay, began creating a haze of salted spray particles. The clinical partnership behind the task, the Marine Cloud Whitening (MCB) program, led by the Educational institution of Washington, is exploring whether such aerosols could assist to slow down climate change through a type of “geoengineering”. What does this term method– and also why is it therefore disputable?