Telecommunications in China pie charts). China's number of Internet users or netizens topped 137 million by the end of 2006, an increase of 23.4% from a year before and 162 million by June 2007, making China the second largest Internet user after the United States. The latest figure (December 2011) have China's internet users exceeding 513 million making it the largest internet user in the world. As of 2004, the largest concentration of Internet users were from Guangdong, Zhejiang, Fujian, Jiangsu, Liaoning, Shandong and Hubei provinces. Beijing, Shanghai and Tianjin also had a high concentration of Internet users, with 28% of Beijing's population
Climate change in the United States produced 6,930 mt (15.7% of the world's total). In the cumulative emissions between 1850 and 2007, the U.S. was at the top in terms of all world nations, involved with 28.8% of the world's total. China's emissions have outpaced the U.S. in CO2 from 2006 onward. The U.S. produced 5.8 billion metric tons of CO2 in 2006, compared to the 6.23 billion coming from China. Per capita emission figures of China are about one quarter of those of the U.S. population. The single largest source of greenhouse gas emissions in the U.S. is power generation. For example, data from 2012