A group of US economists has stated that China is producing a much higher amount of carbon dioxide (CO2) than previously thought, which will hinder global efforts to stabilize atmospheric greenhouse gases. China is the second-largest emitter of CO2 in the world, and some studies suggest it may have already surpassed the United States in emissions. This report may increase pressure on China to commit to binding cuts, something it has so far refused to do. Researchers from the University of California, Berkeley, and UC San Diego published these findings in the May issue of the Journal of Environmental Economics and Management, projecting that China's CO2 emissions will increase by at least 11 percent annually between 2004 and 2010. Previous estimates, including those used by the UN's Intergovernmental Panel on Climate Change, predicted a 2.5 to 5 percent annual increase in CO2 emissions for the same period in the region that includes China. The article is being released at a time when energy and environment ministers from the top 20 greenhouse gas emitting nations are set to meet in Japan to discuss climate change, clean energy, and sustainable development. The G20, including major polluters such as the United States and China, are responsible for about 80 percent of global greenhouse gas emissions. There is increasing pressure on these countries to come to an agreement to stop and reverse the rising levels of CO2 emissions, which are the main contributor to global warming. According to U.S. researchers in a journal report, China is expected to see a significant increase in CO2 emissions by 2010 compared to 2000 levels, surpassing the carbon emissions reductions promised by developed countries during the first commitment phase of the Kyoto Protocol from 2008-2012. China is not required to reduce greenhouse gas emissions from 2008-2012 according to the Kyoto Protocol, but it has agreed to participate in talks with nearly 190 nations in Bali in order to create a new global pact to combat emissions starting in 2013. Researchers analyzed pollution data from 30 Chinese provinces and official waste gas emissions data to gain a more detailed understanding of CO2 emissions up to 2004. UC Berkeley assistant professor Maximillian Auffhammer noted that the growth rate of China's CO2 emissions is exceeding expectations, making it much more difficult to achieve the goal of stabilizing atmospheric CO2 levels. The report mentioned that one reason for the problem was a change in policy after 2000, which allowed provinces more control over constructing power plants. Richard Carson, an economics professor at UC San Diego, pointed out that while wealthier coastal provinces built modern power plants, poorer interior provinces used outdated technology. Carson also noted that the long lifespan of power plants means that these provinces are now stuck with high-emission plants.