.ON APRIL 2ND a device appearing like a snowfall device on the deck of the USS Hornet, a nonexistent aircraft-carrier anchored in San Francisco Bay, began creating a haze of salted spray bits. The scientific collaboration responsible for the job, the Marine Cloud Whitening (MCB) program, led due to the Educational institution of Washington, is examining whether such aerosols could assist to slow climate adjustment with a form of "geoengineering". What performs this phrase mean-- as well as why is it therefore debatable?