Based on a brief review of existing carbon emission methods and models, the future carbon emissions for China was predicted up to 2050. The best probable emission range for China is 2.4-3.3 PgC/a in 2050, with per capita emissions of 1.7-2.3 ton C/cap. According to the upper limit of the best probable range, China's carbon emissions will peak in 2035, with the peak value of 4.4PgC/a and per capita emissions of 3.0 ton C/cap. The best probable range of cumulative emission for China for 2006-2050 is 102-156 Pg C. The cumulative per capita emission for 2006-2050 is 71-109 ton C/ cap, with the upper limit lower than that of America and comparable with developed countries. While for 1850-2005, cumulative per capita emissions for China were only 1/10 that of developed countries and 1/20 of America, which implies that in terms of cumulative per capita emissions, significant gap still exists between China and developed countries.

The authors analyzed carbon emissions, per capita carbon emissions and carbon intensity at provincial and regional levels in China between 1995 and 2007, using data of China’s provincial energy consumption and national fossil fuel carbon emissions. Carbon emissions and per capita emissions were significantly higher in east region than in middle and west regions, whereas carbon intensity was much higher in the latter two regions. Analysis of the Theil index shows that during 1995 and 2007 there was no significant change in the inter-provincial difference in carbon intensity. The decomposition analysis of inter-provincial carbon intensity difference shows that the difference was primarily caused by the intra-regional rather than inter-regional difference, highlighting that even within same region, provincial carbon efficiencies in making economic outputs were highly various. An analysis of stepwise linear regression suggests that fossil energy endowment, industry structure and energy consumption structure play a dominant role in determining provincial carbon intensity. These findings have important policy implications.

Based on historical data on per capita carbon emissions and three socio-economic indicators (industrialization level, urbanization level, and per capita GDP) for the global total and major developed and developing countries, the relationship between carbon emissions and socio-economic development were analyzed. The results show that the process of industrialization and urbanization as well as the accumulation of social wealth, are all inevitably accompanied by large amount of carbon emissions. Therefore, reducing carbon emissions can certainly limit social and economic development. Preliminary analysis suggests that the amount of cumulative per capita emissions corresponding with the peak of industrialization should be at least 40 ton C, though it varies from country to country. For developing countries, considerable carbon emissions quota is required for further industrialization and urbanization as well as improvement of living standards. Therefore, developing countries should fight for their emission rights and financial and technical support from developed countries in the climate negotiations.

Human induced CO₂ emissions have experienced three important periods: 1) 1850-2008, the period since the second industrial revolution; 2) 1950-2008, the rapid economy development period after the Second World War; and 3)1990-2008, the carbon reduction period highlighted by a sign of the “United Nations Framework Convention on Climate Change”. Using data of carbon emissions and population of the world from 1850 to 2008, the authors calculated historical cumulative carbon emissions and the cumulative per capita carbon emissions for the global, developed and developing countries, and analyzed characteristics of carbon emissions for the three periods for China and other major countries. The cumulative global emissions in the past 160 years were 345 PgC (1 PgC = 1015 g of carbon) ; both of the total and per capita carbon emissions in the developed countries were much higher than those in the developing countries for all the three periods. In 1850-2008, the total cumulative emission of the former was 2. 9 times higher than the latter (250 vs. 87 PgC) and the capita value was 11. 2 times higher (257 vs. 23 ton C/ cap) ; in 1950-2008, 2. 3 times higher (193 vs. 85 PgC) and 7. 7 times higher (169 vs. 22 ton C/cap) , respectively; and in 1990-2008, 1.9 times higher (75 vs. 54 PgC) and 5. 3 times higher (58 vs. 11 ton C/ cap). Although the difference in the historical emissions between the developed and developing countries is getting smaller towards the present, both total and per capita emissions of the former are still much higher than the latter, indicating that developed countries should take responsible for the enhanced atmospheric CO2 rising. The cumulative total and per capita emissions of China during the three periods were 31 PgC and 29 ton C/cap, 31 PgC and 28 ton C/cap, and 21 PgC and 16 ton C/cap, respectively. Since the reform and opening up (1980-2008), both the total and per capita emissions of China have experienced rapid growth, with the average annual increase of 0.05 PgC and 0.04 ton C/cap, respectively. These data suggest that China is losing its historical advantage with low per capita emissions, and therefore should take the policies of energy saving and carbon reduction for its sustainable development.