Agence-France Presse: Japan’s announcement Monday of a 25-percent cut in its greenhouse gas emissions could be a game-changer at the UN showdown on climate change in Copenhagen in December, observers said. It could sweep away the who-jumps-first obsession that has bedevilled the world climate talks for nearly two years, they said. "For a long time, everybody has been waiting for everybody else to move in the negotiations…. At this crucial point, the strong message from Japan is exactly what is …