"Experts estimate that when environmental costs are deducted, the average annual GDP growth rate in China will be cut by as much as 2 percentage points," it said.

China posted 9.5 percent economic growth in 2004, its second straight year of expansion above 9 percent.

"Given that the country's economy is rapidly growing while its environment has been worsening, environmental officials and experts have been calling for the adoption of green gross domestic product throughout the country," the China Daily said.

Worried about over-investment that has depleted natural resources and polluted land and rivers, Beijing is trying to change the mentality of many officials still obsessed with rosy growth numbers, which are closely linked to their promotions.

Many analysts inside and outside China have questioned the reliability of Chinese data, prompting authorities last year to say they will start issuing revisions to growth data.

Wang Jinnan, chief engineer for the Chinese Academy for Environmental Planning, said similar calculations were being made at the state level, but results would not be posted until May.

While revising data could give a more realistic picture of regional growth and force officials to be more concerned about the environment, the plan would not be enough to turn things around, Chen Kun of the Chinese Society for Sustainable Development was quoted as saying.