Reuters: G8 nations, papering over deep differences, said on Tuesday they would work toward a target of at least halving global greenhouse gas emissions by 2050 but emphasised they would not be able to do it alone. In a communique released during a summit in northern Japan, the Group of Eight leaders also agreed that they would need to set interim goals on the way to a “shared vision” for 2050 although they gave no numerical targets. Mention of mid-term goals was an advance …