.ON APRIL 2ND a contraption appearing like a snow device on the deck of the USS Hornet, an obsolete aircraft-carrier tied in San Francisco Bay, started producing a mist of salty spray particles. The clinical partnership responsible for the project, the Marine Cloud Brightening (MCB) programme, led due to the University of Washington, is actually looking into whether such sprays may help to decrease environment improvement through a kind of "geoengineering". What performs this term way-- as well as why is it thus disputable?