Reuters: Commonwealth nations representing one-third of the world’s population threw their weight behind accelerating efforts to clinch an "operationally binding" U.N. climate deal in Copenhagen next month, their leaders said on Saturday. Leaders of the 53-nation Commonwealth meeting in Trinidad and Tobago used their summit to bolster a diplomatic offensive seeking wide consensus on how to fight global warming ahead of December 7-18 U.N. climate talks in the Danish capital. "We believe …