Britain-based risk analysts Maplecroft confirmed that Australia is the world's worst polluter per capita in a September 9 report.
Its Climate Change Risk Report 2009/2010 said Australia's heavy reliance on burning fossil fuels for energy had pushed it to the number one position out of 185 nations on a list of the world's top climate vandals, overtaking the United States.
Canada, the Netherlands and Saudi Arabia round out the top five offenders.
By contrast, China emits about 4.5 tonnes per person. India emits only 1.16 tonnes. China has overtaken the US as the biggest single emitter of CO2.
Australia's energy use was also one of the most unsustainable in the industrialised world, said Maplecroft. It ranked Australia at "extreme risk" of being "unable to obtain energy from low carbon sources and operating, investing and lending in an energy intensive country".
The report also assessed emissions from land use change, such as deforestation and unsustainable industrial agriculture. Peru, Brazil and Venezuela were ranked as the countries at greatest risk, said Maplecroft's CO2 Emissions from Land Use Change Index.
However, nations that pollute the least are the most vulnerable to the impacts of climate change. Somalia, Haiti, Afghanistan, Sierra Leone and Burundi are at most risk from environmental breakdowns associated with climate change.
Poor nations such as Nepal, Bangladesh, Sri Lanka, Pakistan, India, the Philippines and Indonesia were also ranked as extreme or high risk.
But big polluters Norway, Finland, Japan, Canada and New Zealand "are the countries best placed to weather the effects", the report concluded.
Of the 28 countries considered at "extreme risk" from global warming, 22 are in sub-Saharan Africa.