Associated Press: The head of the U.N.’s climate change body said Friday that he hopes the United States will take a more active role in fighting global warming once Barack Obama becomes president. “With President-elect Obama, my hope is that the U.S. can take on a leadership role and help to move the negotiations forward,” said Yvo de Boer, executive director of the United Nations Framework Convention on Climate Change. DeBoer spoke in a news conference at a U.N.-sponsored climate change …