Agence France-Presse: Former US vice president Al Gore said Saturday he was optimistic that a global deal to combat climate change would be agreed at a summit in December. In an interview with The Guardian, the Nobel Prize winner said he thought the world had reached a “political tipping point” and would reach agreement when negotiators convene in Copenhagen in December to hammer out a treaty. “There is a very impressive consensus now emerging around the world that the solutions to the economic …