Reuters: A growing number of Americans want the United States to regulate greenhouse gas emissions as the largest oil spill in U.S. history helps boost interest in petroleum alternatives, a poll by two universities found on Tuesday. About 77 percent of 1,204 Americans polled support regulating carbon dioxide as a pollutant, up 6 percentage points from January, according to the poll by researchers at Yale and George Mason universities. The oil catastrophe in the Gulf of Mexico that …