Agence France-Presse: US President-elect Barack Obama has named his energy and environmental chiefs and vowed to bring in a new dawn for US leadership to combat climate change after eight years of Republican foot-dragging. Mr Obama nominated Nobel Prize-winning physicist Steven Chu as his energy secretary, placing the expert in renewable energy on the frontlines of climate change policy and the drive to end the nation’s dependence on foreign oil. “This will be a leading priority of my presidency and …