Reuters: Italy, France and Britain called on Monday for major developing economies like China and India to sign up for a goal of halving the world’s greenhouse gas emissions by 2050 at this week’s expanded G8 summit in Italy. Italian Foreign Minister Franco Frattini said the “extremely ambitious” goal would be the focus of the second day of the summit on Thursday, when U.S. President Barack Obama will chair a meeting of the 17-member Major Economies Forum (MEF). The MEF, which groups …