ABC News: President-elect Obama, in statements to governors, the nation and on the Web, is now promising a profound change in how the U.S. government — and explicitly the White House — will deal with global warming. “Denial is no longer an acceptable response,” he said in a recent radio address and Webcast. “The stakes are too high.” Obama is declaring that he will fight climate change head-on. His declarations come amid what are now persistent TV images and scientific reports …