.ON APRIL 2ND a device looking like a snow machine on the deck of the USS Hornet, a nonexistent aircraft-carrier anchored in San Francisco Gulf, began producing a haze of salty spray particles. The scientific collaboration responsible for the project, the Marine Cloud Whitening (MCB) program, led due to the College of Washington, is actually examining whether such aerosols might assist to slow down environment modification via a type of "geoengineering". What performs this phrase mean-- as well as why is it thus disputable?