Reuters: The world will find it hard to get U.N.-led climate talks back on track in Mexico in 2010 after an unambitious deal agreed in Copenhagen set no firm deadline for a legally binding treaty. Mexico will host the next annual U.N. ministerial talks from Nov. 29 to Dec. 10, 2010 to build on a “Copenhagen Accord” that seeks to limit temperatures rising to no more than 2 Celsius above those recorded in pre-industrial times. But it does not spell out how to achieve that goal. For …