The head of the Nobel Prize-winning U.N. climate panel is urging Japan to exercise leadership during the upcoming Group of Eight summit in setting midterm and long-term global targets to cut carbon emissions. "I would feel very happy if in the G8 meeting all the leaders agree that by 2020 the world has to cut its emissions by X percent and by 2050 it has to cut them by Y percent," Rajendra Pachauri, chairman of the Intergovernmental Panel on Climate Change, said in a recent interview in Tokyo.