Independent (UK): Can the world reach a new deal to combat climate change without the world’s richest country, the world’s sole superpower? Such is the question looming over the Copenhagen climate change summit, now only three weeks away, as the international community waits anxiously to see if President Barack Obama can publicly commit the United States to action on global warming. If he does, it may bring a global agreement in its train. If he does not, the chances of a worthwhile deal in Denmark are …