Can seeding the atmosphere with sulfur dioxide combat climate change?

Wired: It was one of the largest public demonstrations in US history. On June 12, 1982, an estimated 750,000 protesters thronged Central Park in New York City, chanting "No nukes!" and bearing signs reading "Reagan is a bomb — both should be banned" and "Arms are for embracing." Some demonstrators called for unilateral US disarmament, others for renewing arms control talks with the Soviet Union. It was a diverse coalition that had been pulled together by Ken Caldeira, a 25-year-old activist and computer geek. Back then he was paying the rent doing software consulting on Wall Street, but his passion for the environment would eventually lead him to become one of the nation's leading experts on global warming.