Business Green: The latest round of UN climate change talks drew to a close over the weekend with diplomats confident progress had been made on the vexed topic of climate financing, but frustrated by the increasingly fractious stand-off between the US and China. Relations between the two superpowers hit a new low at the close of the week-long talks in the northern Chinese port city of Tianjin, with the US accusing China of undermining the existing Copenhagen Accord and one senior Chinese official …