.ON APRIL 2ND a contraption looking like a snowfall machine on the deck of the USS Hornet, an obsolete aircraft-carrier anchored in San Francisco Bay, started generating a moisture of salty spray particles. The clinical partnership responsible for the task, the Marine Cloud Brightening (MCB) program, led by the Educational institution of Washington, is looking into whether such sprays may assist to reduce climate modification with a form of "geoengineering". What performs this term way-- and also why is it thus disputable?