The inventory lists CO2 emissions from more than 4,000 companies

Australians were found to be the world's worst polluters per capita, producing five times as much CO2 from generating power as China.

The US came second with eight tonnes of the greenhouse gas per head - 16 times more than that produced by India.

The US also produced the most CO2 in total, followed by China.

The Carbon Monitoring for Action (Carma) website is the first global inventory of emissions and looks at 50,000 power stations.

Its data was compiled by the Center for Global Development, a US think-tank.

Least efficient stations

Carma points out that while US power plants emit the most CO2, releasing 2.5bn tonnes into the atmosphere each year, Australian power stations are the least efficient on a per capita basis, with emissions of 10 tonnes, compared with the US's 8.2 tonnes.

TOP 10 EMITTERS National power sector emissions (in tonnes of CO2): US - 2,530 million China - 2,430 million Russia - 600 million India - 529 million Japan - 363 million Germany - 323 million Australia - 205 million South Africa - 201 million UK - 192 million South Korea - 168 million (Source: Carma/CGD)

China's power sector emits the second-highest total amount of carbon dioxide, pumping 2.4bn tonnes of the gas into the atmosphere annually.

However, its emissions are only one fifth of Australia's when measured on a per capita basis.

The UK's 192 million tonnes make it the ninth highest emitter, with per capita CO2 emissions of 3.2 tonnes.

The nation's largest power station, the coal-fired Drax plant, is deemed to be the 23rd most polluting power station in the world.

Powering change

Kevin Ummel, a research assistant at the Center for Global Development, hoped the online inventory would help the push towards a low carbon future.

"The experience of people in the environmental field has been that supplying the public and markets with information that they did not have has often led to improvements in environmental quality," he told BBC News.

CO2 EMISSIONS PER CAPITA Australia - 10.0 tonnes US - 8.2 tonnes UK - 3.2 tonnes China - 1.8 tonnes India - 0.5 tonnes (Source: Carma/CGD)

"There is no reason why this could not happen for carbon emissions."

He said that the data for power stations in the US, Canada, Europe and India came from official, verified reports.

For the power plants that did not have robust reports, Mr Ummel said a model was used to calculate the volume of emissions.

The figure is derived by taking factors such as fuel type, size, age and various other technical specifications in account.

"It turns out that if you have this information then you can predict emissions from the plants with a high degree of certainty," he said.

"Carma is built from a massive database provided by private sector (organisations). It includes every type of fuel and it includes power plants of almost any size.

"Not only do we have the massive plants, like Drax in the UK, but everything down to the solar panels on the local high school.

"We feel quite confident that no-one else has information in such detail."

The philosophy behind the website is to provide people with information that they currently do not have.

"In this website, we do not push a particular agenda or outcome," explained Mr Ummel.

"In fact, we are very interested to see how people choose to use the data."