Guardian: The Guardian has teamed up with more 50 papers worldwide to run the same front-page leader article calling for action at the climate summit in Copenhagen, which begins tomorrow. This unprecedented project is the result of months of negotiations between the papers to agree on a final text, in a process that mirrors the kind of diplomatic wrangling among the world’s governments that is likely to precede any potential deal on climate change. Fifty-six papers in 45 countries …