The world's 10 biggest polluters

1. China

China is the world's worst polluter nation with the highest overall annual emission of greenhouse gases (6,018 million tonne). However, in terms of per capita emissions it is ranked 44th in the world, emitting 4.5 tonne (per person).

It has a renewable energy target (15 per cent of total energy by 2020) and an energy efficiency target (20 per cent reduction by 2010). China has pledged to cut its carbon intensity goal by 40-45 per cent by 2020.

Meanwhile, Australia has the world's highest per capita carbon dioxide emissions from energy use, according to the Maplecroft's CO2 Energy Emissions Index. An average Australian emitted 20.58 tonne of carbon dioxide a year.

Canada was third, followed by the Netherlands and Saudi Arabia. The list of nations most vulnerable to the effects of climate change was topped by Somalia, followed by Haiti and Afghanistan.

China, India, Brazil and South Africa had rejected a Danish suggestion earlier to set a goal of halving world emissions by 2050, saying that rich nations must first set a model by cutting their emissions.

2. United States

The United States is the second worst per capita carbon emitter with for 19.78 tonne of emission per person. America is also ranked the world's second highest polluter with 5,903 million tonns of carbon dioxide emission.

President Barack Obama plans to cut emissions by 17 per cent from 2005 levels by 2020. The world's eyes will be on him when he addresses the Copenhagen summit on climate change next week.

3. Russia

Russia is ranked third with 1,704 million tonnes of carbon dioxide emission. Russia is ready to slash its greenhouse gas emissions by as much as 25 per cent, if other countries follow suit.

4. India

India is world's fourth biggest polluter with 1,293 million tonne of carbon dioxide emission. The average person in India emits just 1.16 tonne per person annually.

But with a rising population, the figures are likely to rise further. The government said it is ready to cut the amount of carbon dioxide (CO2) emitted per unit of economic output -- by between 20 and 25 per cent by 2020 from the 2005 levels.

5. Japan

Japan comes next in the list with 1,247 million tonne of carbon emission.

However, the greenhouse gas pollution fell by 6.2 per cent in Japan in the last financial year. Japan plans to slash greenhouse gas emissions by 25 per cent from 1990 levels by 2020 if developed countries take significant initiatives.

6. Germany

Germany is the 6th biggest polluter in the world with 858 million tonne of carbon dioxide emission. The United Nations says rich nations must cut greenhouse gas emissions steeply by 2020.

7. Canada

Canada which emits 18.81 tonne of carbon per person is the world 7th worst polluter, with an absolute carbon emmission of 614 million tonne.

Canada now plans to reduce emissions by 20 per cent compared with 2006 levels by 2020.

8. United Kingdom

The Uniited Kingdom's emission stands at 586 million tonnes of carbon dioxide emission. The European union agreed to cut emissions by 20 per cent to 2020, compared with 1990 levels.

According to the government records, emission have dropped in the UK.

9. South Korea

South Korea comes next in the worst polluters' list with 514 million tonnes of carbon dioxide emission. South Korea said it would cut greenhouse emissions 4 per cent below 2005 levels by 2020.

10. Iran

Iran has 471 million tonnes of carbon dioxide emission. Iran is worst hit by air and water pollution. The Caspian sea is highly polluted posing a grave threat to marine life and the ecology.