United Press International: Australia has surpassed the United States as the world’s biggest per capita producer of carbon emissions, according to a report by a risk consultancy. The study by British-based Maplecroft released last week finds that Australia tops the CO2 energy emissions index, which measures how much carbon dioxide a country spews into the atmosphere relative to its population size. Carbon emissions are blamed for global warming. Coal-fired power stations, known for high CO2 emissions, …