Australia overtakes U.S. in per capita CO2 emissions

The average Australian contributes 20.58 tons of CO2 to the atmosphere each year to cool homes, drive cars and generate electricity with coal, the UK-based risk assessment company Maplecroft said. The U.S. fell to second at 19.78 tons per inhabitant a year while Canada was third at 18.81 tons.

The ranking indicates how much more people in wealthier nations emit than those in large developing countries, a key argument used by China and India to push for emissions cuts in the U.S., Europe and Japan as the United Nations aims to write a climate-change treaty in Copenhagen in December.

The average Chinese person emits 4.5 tons of greenhouse gases a year and a typical Indian 1.16 tons, according to the survey. Because of populations in excess of 1 billion, the aggregate emissions of those two countries makes them the first and fourth-biggest emitters, according to the U.S. Department of Energy, which ranks the U.S. second and Russia third.

China and India argue that developed nations such as the U.S., Canada and Australia must cut emissions by 40 percent from 1990 levels in 2020, and that poorer countries need room to raise their greenhouse gases to allow them to develop.