Bloomberg: President Barack Obama said he sees political “struggles” ahead as countries deliberate over ratification of a successor treaty to the Kyoto protocol on combating climate change. While it was “a mistake” not to ratify Kyoto, Obama said the U.S. will now focus its efforts on a conference in Copenhagen in December when world leaders will attempt to draw up a post-Kyoto treaty. “This is going to be a big, big project, and a very difficult one, and a very costly one — I don’t want …