Reuters: A key senator on Monday said the committee she leads should approve a bill to tackle global warming before a U.N. climate summit in December, and the U.S. energy secretary said he hoped the bill could be signed into law by then. “I believe we will get this bill out of my committee soon,” Senator Barbara Boxer, who chairs the Environment and Public Works Committee, told reporters after a meeting with U.N. Secretary-General Ban Ki-moon. “Certainly before Copenhagen, and we’re …