Previous estimates, researchers said, suggested the region that includes China would see a 2.5 percent to 5 percent annual increase in CO2 emissions between 2004 and 2010.

But a new analysis at the University of California-Berkeley and University of California-San Diego suggests the annual growth rate for China is at least 11 percent for the same time period.

The researchers' most conservative forecast predicts that by 2010, there will be an increase of 600 million metric tons of carbon emissions in China as compared with the year 2000 -- dramatically overshadowing the 116 million metric tons of carbon emissions reductions pledged by all the developed countries in the Kyoto Protocol.

Based upon their findings, the researchers said current global warming forecasts are "overly optimistic," and action is urgently needed to curb greenhouse gas production in China and other rapidly industrializing countries.

The study by University of California-Berkeley Assistant Professor Maximillian Auffhammer and University of California-San Diego Professor Richard Carson is to appear in the May issue of the Journal of Environmental Economics and Management and is available in the journal's online edition.