Reuters: The next U.S. president should signal a shift in global warming policies before taking office to help a U.N. meeting in Poland in December take steps to work out a new climate treaty, Poland said on Wednesday. Under President George W. Bush, the United States is the only rich nation opposed to the U.N.’s Kyoto Protocol capping greenhouse gas emissions until 2012. Many nations expect a shift under Bush’s successor, whether a Democrat or a Republican. "The American approach …