Reuters: Worries about the costs of combating climate change and rifts between European Union states are likely to strain 185-nation talks in Poland from Monday on a new U.N. treaty to fight global warming. The election of Barack Obama as U.S. president may, however, help the mood at the December 1-12 meeting of 9,000 delegates in the industrial city of Poznan since he has promised more action to slow warming than President George W. Bush. Yvo de Boer, head of the U.N. Climate Change …