Telegraph: With 75 days to go until the Copenhagen summit on climate change, greater urgency is about to be injected into the search for an agreement. World leaders are gathering at the United Nations in New York today for discussions that could determine if there will be a deal and, if so, whether it will be one that makes any difference. In one sense, reaching a strong agreement is even more important than its precise details. The momentum that is building around the world behind the need to cut …