Agence France-Presse: Official smiles and breezy confidence were firmly on display after the latest round of UN talks that aim to build a landmark treaty on climate change. But only six months are left for completing a deal as fiendish in its complexity as it is unprecedented in ambition. Can it be done? In the corridors of Bonn’s Maritim Hotel, where the 12-day round unfolded under the UN Framework Convention on Climate Change (UNFCCC), many delegates seemed to have quietly acknowledged the …