Reuters: U.S. President Barack Obama forged a climate deal with emerging economic powers on Friday, breaking a deadlock at U.N.-led talks, but said the world still had "much further to go" in the fight against global warming. All sides conceded the agreement, which fell far short of United Nations ambitions for the Dec. 7-18 talks, was imperfect but said it was a starting point for a coordinated international effort to avert the catastrophic impacts of climate change. "This progress did …