Abstract:This study calculated the energy structure of Yunnan Province by using a Markov chain, estimated carbon emissions from energy consumption based on an economic growth model and dynamic optimization theory, computed forest carbon sinks based on the CO2FIX model, and predicted net carbon emissions from 2007 to 2050. Furthermore, we analyzed the factors which influenced carbon emission reduction and the contribution of forest carbon sinks, and then investigated a low-carbon economy. The results showed that the curves of carbon emissions from energy consumption and net carbon emissions were an inverted "U" shape, with a peak value of 129.71 MtC in 2035 and 118.89 MtC in 2035. The percentage of coal in the energy structure of Yunnan decreased year by year, while oil, natural gas and non-carbon energy increased slowly, with the non-carbon energy component increasing the fastest among the three thus allowing the energy structure of Yunnan to probably reach a steady state in 2042. In addition, according to emissions targets required in China, an annual decreasing rate of energy intensity of 2.7% is needed. However, our models show that the predicted energy intensity of Yunnan does not reach these targets in the short term. This means that it is currently not possible to achieve the goal of our nation. If the non-carbon energy component in Yunnan's energy structure is improved to 20% in 2050, carbon emissions can be reduced by 12.3% and this is greater than the amount of carbon sinks in 2050, but lower than its peak. The construction of carbon sinks and the use of non-carbon energy are very effective ways to reduce carbon emissions. In terms of forest carbon sinks, the original forest plays a valuable role now and in the immediate future. But, any new forest also has a huge potential as a carbon sink, so afforestation should be encouraged while protecting the original. However, new forests have a growing period, so they cannot reach their full capacity as a carbon sink for many years. Therefore, from the standpoint of carbon sink accumulation, the original forest sinks are still an important part, and are irreplaceable. But these trees can only offset a portion of the provinces' total carbon emissions; what is more important is to radically reduce greenhouse gas emissions by improving the energy structure of the economy, by increasing the speed of technological progress being made and developing hydropower and other (in particular renewable) energy sources. It can also be shown that the per capita net carbon emissions have the same trend along with total carbon emissions, with a peak of 2.18 tC/person in 2035. The amount of per capita emissions is 1.17 tC globally, 1.12 tC in China, and 5.18 tC in the United States. However, in 2009 the amount of per capita emissions is 0.77 tC in Yunnan, below the national level, and is far lower than that of the United States. By 2020, the amount of per capita net carbon emissions will likely be 1.40 tC in China, and that of Yunnan, 1.69 tC, which is 0.29 tC more than that for the whole country.