Agence France-Presse: Almost half of Britons do not believe human behaviour is the main cause of global warming, a new poll showed Sunday, a day before world leaders begin crunch climate talks in Copenhagen. The ICM survey for The Sunday Telegraph newspaper found 52 percent of respondents thought humans were largely responsible for modern day rises in temperatures, but 39 percent said climate change had not yet been proven to be man-made. A further seven percent did not believe climate change was …