U.S. President Barack Obama : Leaders will work together on climate change . At Italy summit , leaders pledge to slash greenhouse gas emissions . Leaders pledge aim to achieve a 50 percent reduction in global emissions by 2050 . Summit takes place in heart of disaster zone where about 500 people died .
U.S. President Barack Obama : Leaders will work together on climate change . At Italy summit , leaders pledge to slash greenhouse gas emissions . Leaders pledge aim to achieve a 50 percent reduction in global emissions by 2050 . Meeting takes place in heart of quake zone where about 300 people died .