Reuters: Cities in six continents joined up to form the world's largest alliance to combat climate change on Wednesday, a move intended to help making ground-level changes to slow global warming. More than 7,100 cities in 119 countries formed the Global Covenant of Mayors for Climate and Energy, a network for helping exchange information on such goals as developing clean energy, organizers said. Cities are responsible for an estimated 75 percent of carbon emissions contributing to climate change and consume...