DAEGU (South Korea): The challenge of providing sustainable energy to a growing global population at a minimal environmental impact dominated debate at the World Energy Congress on Monday."Today, less than one-third of the world's seven billion people consume more than two-thirds of its primary energy supplies," Khalid al-Falih, the president of the world's largest oil exporter, Saudi Aramco, said in a keynote address."But by 2050, a total of nine...