Reuters: German Chancellor Angela Merkel signaled on Tuesday she would visit Copenhagen to push for a U.N. climate deal with other leaders next month, saying failure would set back climate cooperation by years. In Paris, the International Energy Agency (IEA) argued strongly for a U.N. carbon-capping deal, projecting that world use of fossil fuels would otherwise surge by 2030 and push up both energy prices and greenhouse gas emissions. "A failure of the climate conference in Copenhagen …