Agence France-Presse: French President Nicolas Sarkozy pledged Tuesday to work toward reaching a global deal on climate change at the Copenhagen conference in December. Sarkozy told Rajendra Kumar Pachauri, president of the Nobel prize-winning UN panel of climate experts, that the "challenge of a world agreement on climate change must be met," a statement from his office said. The French leader said the Group of Eight summit in Italy in July and a UN climate summit in September were key moments that …