Agence France Presse: French President Nicolas Sarkozy on Friday told the world’s biggest carbon polluters that global warming was becoming a driver of hunger, unrest and conflict, with the war in Darfur a concrete example. "Climate change is already having a considerable impact on security," Sarkozy said in a speech to ministers from 16 economies that together account for 80 percent of the planet’s greenhouse-gas emissions. Water scarcity and rivalry for farmland and fishing resources …