The target of reducing carbon intensity by 40-45 percent in 2020 relative to 2005 level set by China will not fall off behind the current promise and commitment made by rich countries, according to China's top energy expert.

He Jiankun, vice-chairman of China Expert Panel on Climate Change, led his research team to do the study on carbon intensity. As they convert the current emission reduction commitment by rich countries into the index of carbon intensity, they find that the rich countries must reduce the carbon intensity by 30-40 percent from 2005 to 2020, while the US will reduce it by 32 percent.

"Compared with the developed countries which have finished its industrialization process, China's target is really ambitious and challenging," he said.

Carbon intensity, or carbon emission per unit of GDP, is an index to measure the economic production based on greenhouse gas emissions.