WASHINGTON — U.S. researchers once devised a plan to cool the planet by firing artillery shells laced with alumina into the stratosphere.<br /><br />In 1992, researchers for the National Academy of Science published geoengineering options that included artillery shells containing UV-reflective alumina and 16-inch naval rifles.<br /><br />The plan would've seen these massive 1-ton shells half filled with alumina and half-filled with dispersal mechanisms and other materials. The scenario would see 40 10-barrel stations located on empty land areas or at sea due to noise, firing 5 shots per hour, for 24 hours a day for 250 days of the year.<br /><br />The scenario also envisaged the naval rifle firing a projectile containing alumina into the stratosphere. Once there it there it would disperse the substance. Alumina, like sulfur dioxide, can also reflect ultraviolet light.<br /><br />The academy's Committee on Science, Engineering and Public Policy drafted the plan in a 1992 publication titled 'Policy Implications of Greenhouse Warming: Mitigation, Adaptation, and the Science Base'.
